text:
Main Anatomy of Abdomen and Lower Limb
Anatomy of Abdomen and Lower Limb
Vishram Singh
Categories: Medicine\\Anatomy and physiology
Publisher: Elsevier India
ISBN 13: 978-81-312-1569-2
artery1404
lateral1270
anterior1253
posterior1198
medial1147
ligament845
vein687
inferior635
fascia579
femoral509
iliac500
superficial485
lower limb449
inguinal412
abdomen390
transverse379
arteries322
tibial317
obturator309
pelvis297
liver294
gluteal288
plantar284
longus271
tendon271
adductor268
abdominal wall265
lymph262
cutaneous257
lumbar255
bladder254
peritoneum254
abdomen and lower254
fossa253
ligaments251
dorsal250
popliteal249
peroneal247
pubic240
colon233
urethra227
femur226
perineal223
duct222
sacral222
flexor209
rectum208
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Lingua: english
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Page i
ANATOMY OF
ABDOMEN AND LOWER LIMB
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Page iii
Vishram Singh, MS
Professor & Head, Department of Anatomy,
Professor-in-charge, Medical Education Unit,
Santosh Medical College, Santosh University, Ghaziabad, NCR, Delhi.
Examiner in National and International Universities;
Member, Editorial Board, Indian Journal of Otology; Medico-legal Advisor, ICPS, India.
Consulting Editor, ABI, North Carolina, USA.
Formerly at: GSVM Medical College, Kanpur; King George's Medical College,
Lucknow; Al-Arab Medical University, Benghazi (Libya);
All India Institute of Medical Sciences, New Delhi.
Reed Elsevier India Private Limited
Mosby, Saunders, Churchill Livingstone, Butterworth-Heinemann and
Hanley & Belfus are the Health Science imprints of Elsevier.
© 2011 Elsevier
All rights are reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form
or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the
Medical knowledge is constantly changing. As new information becomes available, changes in treatment, procedures,
equipment and the use of drugs become necessary. The authors, editors, contributors, and the publisher have, as far as it is
possible, taken care to ensure that the information given in this text is accurate and up-to-date. However, readers are strongly
advised to confirm that the information, especially with regard to drug dose/usage, complies with current legislation and
standards of practice.
Published by Elsevier, a division of Reed Elsevier India Private Limited.
Registered Office: 305, Rohit House, 3 Tolstoy Marg, New Delhi-110 001.
Corporate Office: 14th Floor, Building No. 10B, DLF Cyber City, Phase-II, Gurgaon-122 002, Haryana, India.
Managing Editor (Development): Shabina Nasim
Development Editor: Goldy Bhatnagar
Manager – Publishing Operations: Sunil Kumar
Manager – Production: NC Pant
Typeset by Olympus Infotech Pvt. Ltd., Chennai, India (www.olympus.co.in).
Printed and bound at EIH Ltd–Unit Printing Press, IMT Manesar, Gurgaon.
Page v
Late Smt. Ganga Devi Singh Rajput
an ever guiding force in my life for achieving knowledge through education
Mrs. Manorama Rani Singh
for tolerating my preoccupation happily during the preparation of this book
Dr. Rashi Singh and Dr. Gaurav Singh
for helping me in preparing the manuscript
Late Professor (Dr.) AC Das
for inspiring me to be multifaceted and innovative in life
Professor (Dr.) A Halim
for imparting to me the art of good teaching
My Students
for appreciating my approach to teaching anatomy and
transmitting the knowledge through this book
Page vii
This textbook on abdomen and lower limb has been carefully planned for the first year MBBS students. It follows the revised
anatomy curriculum of the Medical Council of India. Following the current trends of clinically-oriented study of Anatomy,
I have adopted a parallel approach – that of imparting basic anatomical knowledge to students and simultaneously providing
them its applied aspects.
To help students score high in examinations the text is written in simple language. It is arranged in easily understandable
small sections. While anatomical details of little clinical relevance, phylogenetic discussions, and comparative analogies have
been omitted, all clinically important topics are described in detail. Brief accounts of histological features and developmental
aspects have been given only where they aid in understanding of gross form and function of organs and appearance of common congenital anomalies. The tables and flowcharts summarize important and complex information into digestible knowledgecapsules. Multiple choice questions have been given chapter-by-chapter at the end of the book to test the level of understanding
and memory recall of the students. The numerous simple 4-color illustrations further assist in fast comprehension and retention
of complicated information. All the illustrations are drawn by the author himself to ensure accuracy.
Throughout the preparation of this book one thing I have kept in mind is that anatomical knowledge is required by clinicians
and surgeons for physical examination, diagnostic tests, and surgical procedures. Therefore, topographical anatomy relevant
to diagnostic and surgical procedures is clinically correlated throughout the text. Further, Clinical Case Study is provided at
the end of each chapter for problem-based learning (PBL) so that the students could use their anatomical knowledge in clinical
situations. Moreover, the information is arranged regionally since while assessing lesions and performing surgical procedures,
the clinicians encounter region-based anatomical features. Due to propensity of fractures, dislocations, and peripheral nerve
lesions in the lower limb there is in-depth discussion on joints and peripheral nerves. Similarly due to high incidence of
abdominal hernias and tumors involving abdominopelvic viscera, the inguinal region and abdominal viscera are described in
detail.
As a teacher, I have tried my best to make the book easy to understand and interesting to read. For further improvement of
this book I would greatly welcome comments and suggestions from the readers.
At the outset, I express my gratitude to Dr P Mahalingam, Chancellor, Santosh University, Ghaziabad, NCR, Delhi for providing
an appropriate academic atmosphere and encouragement which helped me a lot in preparing this book.
I am highly grateful to Dr VK Arora, Vice Chancellor, Santosh University for appreciating my work.
I sincerely thank my colleagues in the Department, Professor Nisha Kaul, Dr Ruchira Sethi, and LK Padhy, for their cooperation, critical review of the text and figures, and assistance.
My special thanks is also due to Dr Ruchira Sethi for helping me in the preparation of the index of this book.
It is a special pleasure to acknowledge Professor Poonam Kharb, Hindustan Medical College, Greater Noida for being generous
to see the proofs of abdomen.
I am thankful to Mr Sumeet Rohatgi (Elsevier) for helping me during initial stages of this project.
I gratefully acknowledge the feedback and support of fellow colleagues in anatomy, particularly,
Professors AK Srivastava (Head of the Department), Ashok Sahai, PK Sharma, Mahdi Hasan, and Dr Punita Manik,
King George's Medical College, Lucknow.
Professors Versha Katira (ex-Head of the Department of Anatomy) and Krishna Garg, Santosh World Medical Academy,
Ghaziabad.
Dr NC Goel, Hind Institute of Medical Sciences, Barabanki.
Professors Rani Kumar (Head of the Department), Shashi Wadhwa, Raj Mehra, and Ritu Sehgal, AIIMS, New Delhi.
Professors Gayatri Rath (Head of the Department), RK Suri, and Dr Hitendra Loh, Vardhman Mahavir Medical College and
Safdarjang Hospital, New Delhi.
Professors Veena Bharihoke (Head of the Department) and Dr Rajeev Bhardwaj, UCMS, Shahadra, Delhi.
Professors GS Longia (Head of the Department), People's Dental Academy, Bhopal.
Professors AK Asthana (Dean) and Satyam Khare (Head of the Department), Subharti Medical College, Meerut.
Professor Ramji (Head of the Department), BRD Medical College, Gorakhpur.
Professors Gajendra Singh (Director) and SK Pandey, Institute of Medical Sciences, BHU, Varanasi.
Professor RK Srivastava (Head of the Department & Vice Principal), Rama Medical College, Kanpur.
Professors SL Jethani (Head of the Department), RK Rohtagi, Namita Mehrotra, and Dr Deepa Singh, Himalayan Institute
of Medical Sciences, Jolly Grant, Dehradun.
Professors Shipra Paul (Head of the Department) and Shashi Raheja, Lady Harding Medical College, New Delhi.
Professors JM Kaul (Head of the Department) and Smita Kakkar, Maulana Azad Medical College, New Delhi.
Professors SD Joshi (Head of the Department and Dean) and SS Joshi, Sri Aurobindo Institute of Medical Sciences, Indore.
Professor S Ghatak (Head of the Department), Army College of Medical Sciences, New Delhi.
Professor Suresh P Rathode (Head of the Department), Government Medical College, Bhavnagar (Gujarat).
Professor GP Paul (Head of the Department), Modern Dental College and Research Center, Indore (MP).
Dr Pradeep Bokariya, Mahatma Gandhi Institute of Medical Science, Sevagram, Wardha.
Professors Dr Sundara Pandian (Head of the Department) and Dr SN Kazi, SRM Medical College, Potheri, Chennai.
I gratefully acknowledge the help and cooperation received from the staff of Elsevier, a division of Reed Elsevier India Pvt Ltd.,
especially Mr Vidhu Goel (Director, Clinical Education and Reference Division), Mrs Shabina Nasim (Managing Editor), and
Mrs Goldy Bhatnagar (Development Editor). I highly appreciate the sincerity and dedication of Mrs Shabina Nasim and
Mrs Goldy Bhatnagar.
Page xi
Introduction and Overview of the Abdomen
Osteology of the Abdomen
Anterior Abdominal Wall
Inguinal Region/Groin
Male External Genital Organs
Abdominal Cavity and Peritoneum
Abdominal Part of Esophagus, Stomach, and Spleen
Liver and Extrahepatic Biliary Apparatus
Duodenum, Pancreas, and Portal Vein
Small and Large Intestines
Kidneys, Ureters, and Suprarenal Glands
Posterior Abdominal Wall and Associated Structures
Pelvic Walls and Associated Soft Tissue Structures
Perineum
Urinary Bladder and Urethra
Male Genital Organs
Female Genital Organs
Rectum and Anal Canal
Introduction to the Lower Limb
Bones of the Lower Limb
Front of the Thigh
Medial Side of the Thigh
Gluteal Region
Back of the Thigh and Popliteal Fossa
Front of the Leg and Dorsum of the Foot
Lateral and Medial Sides of the Leg
Back of the Leg
Page xii
Sole of the Foot
Arches of the Foot
Joints of the Lower Limb
Venous and Lymphatic Drainage of the Lower Limb
Innervation of the Lower Limb
Appendix: Multiple Choice Questions
INTRODUCTION AND
OVER VIEW OF THE ABDOMEN
CHAPTER OUTLINE
After studying this chapter, the student should be able to:
Abdominal cavity
define the abdomen and discuss its cavity in detail
– Boundaries
give a brief account of boundaries and contents of the
abdominal cavity, pelvic cavity, and perineum
Pelvic cavity
briefly describe the abdominal viscera and discuss their
briefly describe the pelvic viscera and discuss their
Abdominal viscera
Pelvic viscera
Adrenal glands (suprarenal glands)
Seminal vesicles
Golden facts to remember
The abdomen is the lower part of the trunk below the diaphragm. Its walls surround a large cavity called the abdominal cavity. The abdominal cavity is much more extensive than
what it appears from the outside. It extends upward deep to
the costal margin up to the diaphragm and downward within
the bony pelvis. Thus, a considerable part of the abdominal
cavity is overlapped by the lower part of the thoracic cage
above and by the bony pelvis below.
The abdominal cavity is subdivided by the plane of the
pelvic inlet into a larger upper part, the abdominal cavity
proper and a smaller lower part, the pelvic cavity.
Clinically the term abdominal cavity stands for abdominal cavity proper.
Clinically the importance of the abdomen is manifold.
To the physician, the physical examination of the patient
is never complete until he/she thoroughly examines the
abdomen.
To the surgeon, the abdomen remains an enigma because
in number of cases the cause of abdominal pain and nature
of abdominal lump remains inconclusive even after all possible investigations. To the obstetrician and gynecologist, the
examination of the pelvis and perineum is extremely important. To the venereologist, the main territory of examination
is confined to the external genitalia. To summarize many
branches of medicine such as general surgery, gastroenterology, nephrology, urology, obstetrics, gynecology, and venereology are all confined in the abdomen.
ABDOMINAL CAVITY (FIG. 1.1)
The abdominal cavity is the largest cavity of the body. Its
boundaries and contents are as follows:
The boundaries of the abdominal cavity are:
Superiorly: Diaphragm, which separates it from the
thoracic cavity.
Inferiorly:
Continues with the pelvic cavity at the pelvic
inlet.
Anteriorly: Anterior abdominal wall, formed by muscles.
Posteriorly: Posterior abdominal wall, formed by lumbar
vertebrae and muscles.
Laterally:
Lower ribs and parts of muscles of the anterior
abdominal wall.
• The diaphragm forming the superior boundary moves up and
down with respiration.
• The anterior abdominal wall is firm and elastic.
Thoracic cage
Costal margin
10th rib
cavity proper
Pelvic inlet
Pelvic diaphragm
Fig. 1.1 Abdominal cavity.
Firmness of anterior abdominal wall protects the abdominal viscera
and its elasticity allows the expansion of the abdominal viscera.
The posterior abdominal wall is osteomuscular and rigid. Its rigidity provides support to the abdominal organs.
CONTENTS (FIGS 1.2 AND 1.3)
The organs and glands of digestive and urinary systems
occupy most of the abdominal cavity. These organs and
glands are listed below:
Stomach, small intestine, and most of the large intestine.
Liver, gallbladder, and pancreas.
Two kidneys and upper part of the ureters.
Adrenal glands (also known as suprarenal glands).
Other structures include blood vessels, lymph vessels,
nerves, spleen, and lymph nodes.
The pelvic cavity is roughly funnel shaped. Its boundaries
and contents are as follows:
The boundaries of the pelvic cavity are:
Superiorly: Continuous with the abdominal cavity at the
pelvic inlet.
Pelvic diaphragm.
Posteriorly: Sacrum and coccyx.
Anteriorly: Pubic bones.
Hip bones.
Transverse colon
Part of omentum (cut)
Descending colon
Ascending colon
Fig. 1.2 Organs occupying the anterior part of the abdominal cavity.
Inferior surface
of diaphragm
Splenic artery
Right adrenal gland
Right kidney
Left kidney
Left ureter
Sigmoid colon
Fig. 1.3 Organs occupying the posterior part of the abdominal cavity. (The broken line shows the position of the stomach.)
The part of pelvis below the pelvic diaphragm is termed perineum
(Fig. 1.1).
The pelvic cavity contains the following structures:
1. Loops of the small intestine.
2. Sigmoid colon, rectum, and anal canal.
3. Urinary bladder, lower part of the ureters, and urethra.
4. Reproductive organs:
(a) Prostate gland, seminal vesicles, vas deferens, and
ejaculatory ducts in male.
(b) Uterus, uterine tubes, ovaries, and vagina in
female.
The pelvic and urogenital diaphragms forming the inferior boundary
of the pelvic cavity support the pelvic viscera and regulate the act
of defecation, micturition, and parturition.
The walls of the abdominal cavity and most of the viscera
present within it are covered or enclosed by an extensive
Right ureter
Ductus deferens
Seminal vesicle
Pubic bone
Anal canal
Fig. 1.4 Structures present in the male pelvis.
Uterine tube
Fig. 1.5 Structures present in the female pelvis.
serous membrane called peritoneum. The peritoneum consists of parietal and visceral layers, which are continuous with
each other and enclose a potential space called peritoneal
cavity.
• All the abdominal viscera are intra-abdominal but extraperitoneal
except the ovaries in female.
• The peritoneal cavity is a closed sac in the male but in the
female it is an open sac and communicates to the exterior
through the openings of the uterine tubes.
Clinical correlation
• The upper part of the abdominal cavity is overlapped by the
lower thoracic region and the lower part by the gluteal region.
Therefore, the penetrating wounds of these regions frequently involve the abdominal viscera also.
• The upper abdominal contents such as liver and spleen fill
the concavity of the diaphragm. Therefore, it is easy for the
surgeons to reach these organs through the thorax and
diaphragm or through the anterior abdominal wall.
(Contd)
• The mobile diaphragm forms the upper boundary/limit of
the abdominal cavity, the abdominal contents descend with
it on deep inspiration. This is made use of in clinical examination of certain organs, such as liver and enlarged spleen,
which can be palpated through the anterior abdominal wall,
inferior to the costal margin on deep inspiration, though
hidden by the thoracic cage in quiet respiration.
The perineum is an area outlined by the diamond-shaped
pelvic outlet. Its boundaries and contents are as follows:
The small intestine is a convoluted tube connecting stomach
with the large intestine. It is about 6 m in length and extends
from pyloric sphincter to the ileocecal junction. The small
intestine is located in the central and lower parts of the
abdominal cavity surrounded by the large intestine. It consists of three parts: (a) duodenum, (b) jejunum, and (c) ileum.
The duodenum is proximal short curved (c-shaped) portion and is about 25 cm long. It is the widest and most fixed
part of the small intestine. The ducts from gallbladder and
liver, and pancreas enter it.
The jejunum is the name given to the upper two-fifth of
the remainder of the small intestine and the lower three-fifth
is termed ileum.
The boundaries of perineum are:
Anteriorly: Pubic symphysis.
Posteriorly: Coccyx.
Ischiopubic rami (anteriorly) and sacrotuberous
ligaments (posteriorly).
The roof of perineum is formed by the pelvic diaphragm
and its floor is formed by the skin.
The contents of perineum are external genitalia (penis and scrotum with its contents in male and vulva in female) and anus.
The abdominal viscera includes stomach and intestines, their
associated glands (liver and pancreas), blood and lymph vessels, spleen, kidney, and suprarenal glands.
The main functions of the small intestine are digestion of
food and absorption of nutrients.
The large intestine begins at the end of the ileum as cecum
terminates at the anus. It is about 1.5 m long and forms an
arch around the coiled up small intestine. For descriptive
purposes, it is divided into following seven parts:
Cecum and appendix.
Ascending colon.
Transverse colon.
Descending colon.
Sigmoid colon.
Rectum.
Anal canal.
The main functions of the large intestine are as follows:
The stomach is the most dilated part of the digestive tube. It
is J-shaped and located in the abdominal cavity below the
diaphragm slightly to the left of the midline. The capacity of
the stomach is about 1500 ml in the adult.
The main functions of the stomach are as follows:
1. Churning and breaking of food and mixing it with the
gastric juice secreted by specialized glands in its mucosa.
2. Storing the food temporarily.
3. Secreting intrinsic factor needed for absorption of
vitamin B12.
1. Absorption of water and salts.
2. Formation and excretion of faeces.
The liver is the largest gland of the body. It is located in the
upper right part of the abdominal cavity. It has two main lobes:
right and left. The right lobe is much larger than the left lobe.
Some important functions of the liver are as follows:
1. Metabolism of carbohydrate, fat, and protein.
2. Detoxification of drugs and poisons.
3. Storage of glycogen and fat-soluble vitamins (ADEK).
4. Secretion of bile.
The gallbladder is a pear-shaped organ located on the under
surface of the right lobe of the liver. It receives bile from the
liver, which it stores and concentrates. When fatty food
enters the duodenum, the bile is poured into the intestine
through the bile duct by the contraction of the walls of the
bladder.
Jaundice: It is a clinical condition characterized by yellowing of
the skin and sclera of the eyes. It occurs when bile enters the
blood in liver diseases such as hepatitis or cirrhosis of the liver
where the liver cells break down and release bile into the blood.
Bile also enters into the blood when outlet of bile from the
gallbladder to intestine through the bile duct is blocked.
at the back of the abdominal cavity on the left side behind
the stomach.
The main functions of the spleen are as follows:
1. Destruction of red blood cells.
2. Production of fresh lymphocytes for the blood stream.
The kidneys are two bean-shaped organs situated on the
posterior abdominal wall, one on each side of the vertebral
column, behind the peritoneum. The right kidney usually
lies at a slightly lower level than the left.
The main function of the kidney is to secrete and excrete urine.
The composition of blood must not vary beyond certain limits if the
tissues of the body are to remain healthy. This regulation depends
on the removal of harmful waste products and maintenance of
water and electrolyte balance.
The pancreas is elongated, soft, pale, and finely lobulated
grey gland. It is about 12–15 cm in length and lies transversely across the posterior abdominal wall. It consists of
broad head, neck, body, and narrow tail. The head of gland
lies within the curve of the duodenum, the body behind the
stomach, and tail in front of the left kidney. The tail extends
as far as the spleen.
The ureters are two tubes, which connect the kidneys to the
urinary bladder. Each ureter is usually 25 cm long with a
diameter of about 3 mm.
The pancreas is an exo-endocrine gland. The function of
exocrine pancreas is to produce pancreatic juice containing
enzymes that digest carbohydrates, proteins, and fats.
The function of endocrine pancreas is to secrete hormones, insulin, and glucagon, which control the blood glucose level.
The ureters transport urine from the kidneys to the urinary
Diabetes mellitus: Deficiency of insulin results in diabetes
mellitus. The blood sugar level rises above the renal threshold
and glucose is lost in the urine.
The spleen is a large wedge-shaped mass of vascular and
lymphoid tissue. It is purplish-red in color and lies high up
There are two suprarenal glands—right and left. Each gland
caps the upper pole of the corresponding kidney. The right
gland is triangular whereas the left gland is semilunar in
shape. Each gland consists of two parts: cortex and medulla.
The function of cortex is to secrete a number of steroid hormones, which are responsible for: (a) maintenance of electrolyte and water balance, (b) maintenance of blood sugar
concentration and of liver and muscle glycogen, and (c) control of inflammatory reactions.
The function of medulla is to secrete adrenaline and noradrenaline in the blood, which serve as neurotransmitters.
The pelvic viscera in males are urinary bladder, prostate, and
rectum; and in females are urinary bladder, uterus, and rectum.
The urinary bladder is a reservoir of urine. Its size, shape,
and position vary with the amount of urine it contains.
When empty it lies in the pelvic cavity, but when distended
with urine it expands upward and forward into the abdominal cavity. The bladder can hold up to 500 ml (rarely 600 ml)
of urine, though this would cause pain. The desire to empty
the bladder is felt when it contains around 250–300 ml of
The two ureters enter into it through its posterior wall.
The urethra leaves the bladder at its neck. The neck of the
bladder is the lowest and most fixed part of the urinary bladder. A thickening of smooth muscle called internal urethral
sphincter surrounds the opening of the urethra.
The urinary bladder stores urine and expels it into the urethra.
The urethra is a narrow canal that extends from the internal
urethral orifice in the urinary bladder to the external urethral orifice.
In a male, the urethra is about 18–20 cm long and in a
female, it is about 4 cm long.
In a male, the urethra serves as a common passage for both
semen and urine whereas in a female, the urethra discharges
urine from the body.
The seminal vesicles are two small fibromuscular pouches
lying between the base of the bladder and the rectum.
The seminal vesicles secrete an alkaline fluid containing nutrients to sperms and forms about 60% of the seminal fluid.
The ejaculatory ducts are two narrow tubes about 1 cm long.
The duct of seminal vesicle and ductus deferens unite to form
ejaculatory duct. They traverse the prostate gland to open into
the urethra within the gland (prostatic part of urethra).
The ejaculatory ducts expel the secretions of testes and seminal
vesicles into the prostatic urethra.
The uterus is a hollow, thick-walled, muscular organ situated
in the pelvic cavity between the urinary bladder and the rectum. It is pear shaped and flattened anteroposteriorly. In the
majority of women it leans forward (anteflexion) and bends
forward (anteversion) almost at a right angle to the vagina.
In erect posture, the uterus lies in almost horizontal position.
The uterus is divided from above downward into following three parts: (a) fundus, (b) body, and (c) cervix. The
cervix protrudes into the vagina through its anterior wall
and opens into it at the external os.
Above on either side, it communicates with the uterine
tubes, which open into it. Below it communicates with the
The functions of the uterus after puberty are:
The prostate is a fibromuscular glandular gland, which surrounds the commencement of the urethra in the male. It is
situated in the pelvic cavity behind the pubic symphysis and
in front of the rectum. It is about the size of chestnut and is
traversed by the urethra and ejaculatory ducts.
The function of the prostate is to secrete a thin, milky fluid,
which forms about 30% of the semen, and gives it a milky
appearance. The prostatic secretion is alkaline in nature and
provides nourishment to the sperms.
1. Responsible for menstrual cycle (MC).
2. Provides implantation to zygote in its wall.
3. Allows growth and development of the embryo and fetus.
The vagina is fibromuscular tube, which extends obliquely
downward and forward from the uterus to the vestibule of
vagina – the elliptical space between the labia. It is situated
between the urinary bladder in front, and the rectum and
anal canal behind. However, the vagina has no secretory
glands though it is kept moist by the cervical secretions.
The functions of the vagina are as follows:
1. Act as a receptacle for penis during coitus.
2. Provides an elastic passage to the baby during child birth.
There are two uterine tubes. Each tube is about 10 cm long,
which extends from the side of the uterus (between the fundus and body) to the ovary where it opens into the peritoneal
It is divided into the following parts from distal to the
proximal end: (a) infundibulum, (b) ampulla, (c) isthmus,
and (d) intramural.
Right lumbar
Right iliac fossa
Epigastric
Hypogastric
Left lumbar
Left iliac fossa
The functions of uterine tubes are as follows:
1. Transports the ovum from ovary to its lumen and provides an ideal site for fertilization.
2. Transports the fertilized ovum to uterine cavity for
implantation.
The ovaries are female gonads. Each ovary is about the size
and shape of almond and is situated in shallow fossa on the
lateral wall of the pelvic cavity behind and below the distal
end of the uterine tube.
The ovaries begin to function at puberty and continue
to discharge ova at monthly intervals from about the age of
13 years to about the age of 45 years.
Disorders of the abdomen: The disorders of the abdomen and
pelvis are numerous; the important ones are as follows:
(a) Hernia: It is the protrusion of an organ through the wall,
which contains/retains it. The common abdominal hernias
are inguinal, umbilical, femoral, and incisional; the order
reflecting their frequency.
(b)Abdominal pain: Many intra-abdominal diseases present
with pain only. The two important features of an abdominal
pain are its site and its nature. If a clinician knows about
these features, he/she has a good chance of making a correct
diagnosis. In general: (a) The upper abdominal pain mostly
occurs due to involvement of gallbladder, stomach,
Fig. 1.6 Regions of the abdominal cavity.
duodenum, and pancreas. (b) The central abdominal pain
usually occurs due to involvement of small bowel and kidneys. (c) The lower abdominal pain occurs due to involvement of urinary bladder, uterus, cecum, and sigmoid colon.
(c) Abdominal mass: The common causes of abdominal masses
are: hepatomegaly (enlargement of liver), splenomegaly
(enlargement of spleen), hydronephrosis (enlargement of the
kidney), pseudocyst of pancreas, mesenteric cysts, carcinoma of stomach, enlargement of gallbladder, accumulation
of feces, retention of urine in urinary bladder, ovarian cyst,
pregnant uterus, uterine fibroids, and appendicular mass.
(d) Abdominal distension: The six common causes of
abdominal distension are Fetus, Flatus (gas in intestine),
Feces (impaction of feces in bowel), Fat, Fluid (ascites),
and Fibroids.
The names of six conditions that cause abdominal
distension start with the letter 'F'.
The distension (prominent abdomen) is normal in front
and young children due to following reasons:
– Their gastrointestinal tract contains a considerable
amount of air.
– Their liver is relatively large in size.
– Their abdominal muscles are relatively less toned.
Regions of the abdomen: By convention, the abdominal cavity is
divided into nine regions (Fig. 1.6). This facilitates the description
and position of organs it contains.
Largest gland in the body
Most dilated part of the digestive tube
Pelvic organ with thickest muscular walls
Most of the abdominal cavity is occupied by
Organs and glands of the digestive system
Bulk of semen is formed by
Secretion of seminal vesicles
Commonest cause of abdominal distension in married female
Lower ribs and costal cartilages
Lumbar vertebrae
Features of typical lumbar vertebrae
Features of atypical fifth lumbar vertebra
Special features of lumbar vertebrae
Anatomical position
Special features (attachments and relations)
define the costal margin and describe its formation
enumerate the identifying features of lumbar vertebrae
classify the lumbar vertebrae into typical and atypical
vertebrae and discuss the special features of typical
discuss the general and special features of the sacrum
present a brief account of the coccyx and describe
elucidate the parts of hip bone and briefly discuss their
identify parts of bony pelvis and briefly discuss their
understand the given clinical case and answer the related
– General features
– Special features
– Ossification
Bony pelvis
– Anatomical position
Clinical case study
The osteology of abdomen deals with the bones of the
abdomen and pelvis.
The bones of the abdomen and pelvis are as follows
(Fig. 2.1):
Lower ribs and costal cartilages.
Lumbar vertebrae.
Sacrum.
Coccyx.
Hip or innominate bone.
The ribs and costal cartilages are described in detail in
Anatomy of Upper Limb and Thorax. The costal cartilages of
7th, 8th, 9th, and 10th ribs articulate with each other to form
the costal margin. The 11th and 12th ribs are shorter and do
not articulate either with the transverse processes of 11th
and 12th thoracic vertebrae or with the adjacent costal cartilages. As a result they can move independently of the other
ribs hence are termed floating ribs.
The lumbar vertebrae consist of same elements as the thoracic vertebrae but are more massive in keeping with the
greater load, which they have to transmit. There are five lumbar vertebrae out of which first four (L1 to L4) are typical
and fifth (L5) is atypical.
Identifying features of the lumbar vertebrae are as follows:
1. Massive reniform bodies.
2. Absence of costal facets on the body.
3. Absence of foramina transversaria in the transverse
4. Presence of accessory and mammillary processes.
5. Thick quadrilateral spinous processes.
(L1, L2, L3, L4)
GENERAL FEATURES (FIG. 2.2)
1. The body is massive and reniform.
2. Its transverse diameter is more than the anteroposterior
diameter.
3. It is constricted in front and at the sides.
4. The size of the body increases progressively from first to
fifth lumbar vertebra.
Xiphoid
Lower ribs
and costal
cartilages
Costal
Iliac crest
Tubercle of
iliac spine
Pectineal
symphysis
Fig. 2.1 Bony landmarks on the anterior abdominal wall.
5. The length of the body is slightly greater anteriorly. This
contributes to the forward convexity of the lumbar vertebral column.
6. The body has no costal facets on its sides.
Vertebral Foramen
1. It is triangular in shape.
2. It is larger than in the thoracic vertebrae but smaller
than in the cervical vertebrae.
Vertebral Arch
Pedicles
– The pedicles are short and strong processes.
– They project backward from the upper parts of the body;
as a result, the inferior vertebral notches are much deeper
than the superior ones.
Laminae
– The laminae are short, thick, and broad plates.
– They are directed posteromedially.
– The overlapping between the laminae of the adjoining
vertebrae is minimal.
– The spine is quadrilateral in shape.
– It projects almost backward.
Transverse processes
– The transverse processes are thin and tapering.
– They are homologous to the ribs in the thoracic region.
– The posteroinferior aspect of each transverse process presents a small rough elevation called accessory process. This
represent the true transverse process of the vertebra.
Superior articular
Mammillary process
Transverse process
Pedicle
Mammillary
Inferior vertebral
Inferior articular
Superior articular process
Accessory process
Fig. 2.2 Typical lumbar vertebra: A, superior view; B, lateral view; C, posterior view.
– A vertical ridge near the tip marks the anterior surface of
each transverse process.
Superior articular processes
– The facets on the superior articular processes are concave,
which project backward and medially.
– The superior articular processes lay farther apart than the
inferior articular processes.
– Their posterior borders are marked by a rough elevation
called mammillary process.
Inferior articular processes
– The inferior articular processes lie nearer to each other
than the superior articular processes.
– They bear convex articular facets, which face forward and
laterally.
(thick, short, and
pyramidal in shape)
Superior articular facet
(face more backward
than medially)
FEATURES OF ATYPICAL FIFTH LUMBAR
VERTEBRA (L5)
The fifth lumbar vertebra presents the following atypical
(distinguishing) features (Fig. 2.3):
1. The transverse processes are thick, short, and pyramidal
in shape. Their base is attached to the whole thickness of
Fig. 2.3 Fifth lumbar vertebra: A, as seen from above; B, as
seen from the side.
the pedicle and encroaches on the side of the body. They
seem to be turned upward.
The spine is small, short, least substantial, and rounded
at the tip.
The body is largest of all lumbar vertebrae. The vertical
height of the anterior surface of the body is more than
that of the posterior surface. This difference is responsible for sharp/prominent lumbosacral angle (120°).
The superior articular facets look more backward
than medially and inferior articular facets look more
forward than laterally as compared to typical lumbar
vertebrae.
The distance between the inferior articular processes is
equal or more than that between the superior articular
Fawcett's rule for identification of individual lumbar vertebrae
(Fig. 2.4): According to this rule, an individual lumbar vertebra can be
identified if it is looked from behind. A four-sided figure can be constructed by joining the four articular processes. The quadrangular figure thus constructed differs in different lumbar vertebrae as given in
the box below.
Shape of quadrangular figure
• Trapezium with top broader
than base
• 1st/2nd lumbar
L1/L2
Fig. 2.4 Quadrangular figures formed by joining the articular
process of lumbar vertebra (Fawcett, H.E. 1932).
Table 2.1 Characteristic features of the lumbar vertebrae
• Rectangle with long
• 3rd lumbar
• Square
• 4th lumbar vertebra
Massive and kidney shaped
Triangular and relatively
smaller than in cervical
Long and slender with
accessory process on the
posterior surface of base of
each process
Articular processes
• Superior articular facets
directed posteromedially
• Inferior articular facets
directed anterolaterally
Spinous process
Short, thick, broad, and
hatchet shaped
The characteristic features of typical lumbar vertebrae are
summarized in Table 2.1.
SPECIAL FEATURES OF LUMBAR
VERTEBRAE (FIG. 2.5)
The special features include attachment of muscles and ligaments, which are described below:
1. Anterior longitudinal ligament is attached on the upper
and lower borders of lumbar vertebral bodies anteriorly.
2. Posterior longitudinal ligament is attached on the upper
and lower borders of lumbar vertebral bodies posteriorly.
Psoas major muscle
Psoas fascia
Anterior longitudinal ligament
Thoracolumbar fascia
Quadratus lumborum
Crus of diaphragm
Anterior layer
Posterior longitudinal ligament
Posterior layer
Faint ridge on the front
of transverse process
Thoraco-lumbar fascia
Multifidus
Erector spinae
Fig. 2.5 Attachments of the lumbar vertebra.
3. Right crus of diaphragm is attached on the front of
upper three lumbar vertebral bodies.
4. Left crus of diaphragm is attached on the front of upper
two lumbar vertebral bodies.
5. Psoas major arises by fleshy slips from upper and lower
borders of all lumbar vertebrae.
6. Tendinous arches of psoas major are attached across the
constricted parts of the bodies on each side.
7. Ligamenta flava are attached to the laminae of adjacent
8. Posterior layer of thoraco-lumbar fascia is attached to
the spinous processes of lumbar vertebrae.
9. Supraspinous and interspinous ligaments are attached
to the spinous processes of lumbar vertebrae.
10. Erector spinae and multifidus muscles are attached to
11. Middle layer of thoraco-lumbar fascia is attached to the
tips of transverse processes of the all lumbar vertebrae.
12. Medial and lateral arcuate ligaments of diaphragm are
attached to the tips of transverse processes of L1 vertebra.
13. Anterior layer of thoraco-lumbar fascia is attached to
the faint ridge on the front of transverse processes.
14. Multifidus and intertransverse muscles are attached to
the mammillary processes.
15. Iliolumbar ligaments are attached to the tips of the
transverse processes of the fifth lumbar vertebra.
16. Accessory and mammillary processes provide attachment to the medial intertransverse muscles.
A lumbar vertebra ossifies from three primary centers and
five secondary centers. The sites of appearance and age of
fusion are given in Table 2.2.
Table 2.2 Ossification of a lumbar vertebra
Ossification centers
Primary centers (appear
between 7th and 8th week
of intrauterine life)
• One for body
• Two for two halves of the
• Two halves of vertebral
arch fuse during 1st year
• Vertebral arch fuses
with the body during
Secondary centers
(appear at about puberty)
• Two for annular epiphysis
of the upper and lower
surfaces of the body
• Two for tips of the
• Two for mammillary processes
• One for the tip of the spine
The portions derived from
secondary centers fuse
with rest of the bone at
about 25 years
• Sacralization of the fifth lumbar vertebra: It is the fusion of
the fifth lumbar vertebra with the sacrum. The fusion may
be complete or incomplete. The transverse process of L5
may articulate with ala of sacrum and/or ilium and compress the L5 spinal nerve. This condition occurs in about
5% of normal individuals.
• Spina bifida: It occurs due to nonfusion of two halves of the
vertebral arch. In this condition the meninges and spinal
cord are exposed and may herniate out in the midline
through the gap. (For details see Clinical and Surgical
Anatomy by the author.)
• Spondylolisthesis: It is the forward slipping of the fifth lumbar
vertebra over the sacrum. Sometimes the inferior articular
processes, laminae, and spine of L5 vertebra are separated
from the rest of the vertebra, which slip forward on the
sloping superior surface of the sacrum. This condition may
clinically present as backache and pain radiating along the
course of the sciatic nerve—sciatica (also see p. 507).
• Cauda equina syndrome: It is caused due to compression of
cauda equina—a leash of nerve roots of L2 to S1 around the
filum terminale. Clinically, it presents as:
(a) Flaccid paraplegia.
(b) Saddle-shaped anesthesia.
(c) Late bladder and bowel involvement leading to incontinence of urine and feces.
(d) Impotence.
(e) Absence of knee and ankle jerks.
The sacrum (Latin sacrum ⫽ sacred) is large flattened
triangular/wedge-shaped bone formed by the fusion of five
sacral vertebrae (Fig. 2.6). The sacrum articulates on either
side with the hip bone to form the sacroiliac joint. The functions of sacrum are as follows:
1. Forms posterior part of the bony pelvis.
2. Supports the vertebral column.
3. Transmits the weight of the body to the pelvic girdle
through the sacroiliac joints.
To keep the sacrum in anatomical position, hold it in such a
way that:
1. Its smooth pelvic surface faces downward and forward;
and its rough dorsal surface faces upward and backward.
Sacral canal
Sacral promontory
Vertical sacral crests
Median sacral crest
Transverse ridges
Intermediate sacral
Anterior sacral
foramina
Inferolateral angle
of sacrum
Apex of sacrum
Lateral sacral
Dorsal sacral
Auricular surface
Lateral sacral crest
Fig. 2.6 General features of sacrum: A, pelvic surface; B, dorsal surface; C, lateral surface.
Sacral cornu
2. Upper surface of the body of the first sacral vertebra
slopes forward at an angle of about 30°.
3. Upper end of the sacral canal is directed almost upward
and slightly backward.
In an articulated skeleton, the sacrum is placed obliquely like a wedge
between the two hip bones. Owing to its oblique situation, it forms an
angle with the lumbar vertebral column called lumbosacral angle. It
measures about 140° in male and 135° in female.
The sacrum presents the following general features:
1. Base.
2. Apex.
3. Four surfaces: pelvic, dorsal, and two lateral (right and
left) surfaces.
4. Sacral canal.
The base of the sacrum is directed upward and forward. It is
formed by the superior surface of the first sacral vertebra. It is
divided into three parts: median part and right and left lateral
parts. The median part is formed by the oval upper surface of
the body of the first sacral vertebra. Its anterior border is
termed sacral promontory. The right and left lateral parts are
fan shaped and represent the upper surfaces of lateral masses
of sacrum called alae. The lateral masses represent the fused
costal and transverse elements of the sacral vertebrae.
1. Body of the first sacral vertebra articulates with the fifth
lumbar vertebra of upper surface.
2. Vertebral foramen lying behind the body is triangular
and leads into the sacral canal.
3. Pedicles are short and directed backward and laterally.
4. Laminae are quite oblique.
5. Transverse processes are massive and fused with corresponding costal transverse element of lower sacral vertebrae to form the broad sloping lateral masses called alae
of sacrum.
6. The spinous process forms the first spinous tubercle.
7. The superior articular processes are prominent and project upward. They flank the superior opening of sacral
canal.
1. It is a lower narrow blunt extremity formed by the inferior surface of the body of the fifth sacral vertebra.
2. It bears an oval facet for articulation with coccyx to form
the sacrococcygeal joint.
Pelvic Surface (Fig. 2.6A)
The pelvic surface of sacrum is concave and directed downward and forward. It presents the following features:
1. Four transverse ridges that indicate the lines of fusion of
five sacral vertebrae.
2. Lateral to transverse ridges are four anterior sacral foramina
through which ventral rami of upper four sacral nerves
come out.
3. The part of bone lateral to foramina is the lateral mass.
Dorsal Surface (Fig. 2.6B)
The dorsal surface of sacrum is rough, irregular, and convex.
1. In the median plane, there is median sacral crest that
bears three or four spinous tubercles representing spinous processes of fused sacral vertebrae.
2. Lateral to median crest, the posterior surface is formed
by fused laminae of upper four sacral vertebrae.
The laminae of the fifth sacral vertebra fail to join
behind, forming a U-shaped gap called sacral hiatus.
3. Lateral to laminae are four articular tubercles in line with
superior articular process of the first sacral vertebra.
4. The inferior articular processes of the fifth sacral vertebra project downward as sacral cornua on either side of
sacral hiatus.
The most prominent features on the dorsal surface of sacrum are as
• Five vertical crests:
– Median sacral crest, formed by the fusion of sacral spines.
– Two intermediate sacral crests, one on either side of median
crest, are formed by the fusion of articular processes of sacral
– Two lateral sacral crests, one on each side of lateral to
intermedial crest, are formed by the fusion of transverse
processes of sacral vertebrae.
• Sacral hiatus
Lateral Surfaces (Fig. 2.6C)
Each lateral surface is the lateral aspect of lateral mass
formed by the fusion of transverse and costal elements of
sacral vertebrae.
1. It is wide above and narrow below.
2. Lower narrow part turns abruptly medially to form the
inferolateral angle of the sacrum.
3. Upper wider part bears an inverted L-shaped auricular
surface anteriorly and a deeply pitted area posteriorly.
The auricular surface is so called because of its resemblance to the auricle of the external ear. It extends on to
the upper three or three and half sacral vertebrae.
2. Coccygeal (C×1) nerves.
3. Filum terminale.
1. The sacral canal is formed by the superimposed vertebral
foramina of the sacral vertebrae.
2. The upper end of the canal is directed upward in line
with vertebral canal of lumbar vertebrae, and its lower
end opens at sacral hiatus.
3. The sacral canal communicates with the pelvic and dorsal
sacral foramina through the intervertebral foramina.
• Sacralization: The term sacralization means incorporation
of the fifth lumbar (L5) or first coccygeal vertebra (C1) in
the sacrum. In sacralization the number of sacral foramina
is increased unilaterally or bilaterally.
• Lumbarization: In this condition, the first sacral (S1) vertebra is separated from the sacrum and fused with the fifth
lumbar vertebra (L5). As a result, the number of sacral
foramina is reduced to three pairs.
Contents of Sacral Canal
1. Lower part of cauda equina (sacral and coccygeal nerve
roots).
3. Spinal meninges.
4. Lateral sacral vessels.
SPECIAL FEATURES (ATTACHMENTS AND
RELATIONS) (FIG. 2.7)
The dural tube and arachnoid mater extend up to the second sacral
vertebra.
1. The upper surface of the body of the first sacral vertebra
articulates with the L5 vertebra to form the lumbo-sacral
joint.
Structures Emerging through Sacral Hiatus
1. Fifth sacral (S5) nerves.
Sympathetic trunk
Lumbosacral trunk
Median sacral artery
Iliolumbar artery
Sympathetic trunks
Obturator nerve
Ventral rami of
sacral nerve
Coccygeus
Area related to
Erector spinal
Fig. 2.7 Special features of sacrum: A, pelvic surface; B, dorsal surface.
2. The smooth medial part of ala is related to the following
four structures from medial to lateral side (Fig. 2.7A):
(a) Sympathetic chain
(b) Lumbosacral trunk
(c) Iliolumbar artery
(d) Obturator nerve
The ventral ramus of L5 nerve is so taut that it
grooves the ala.
3. The rough lateral part of the ala gives origin to iliacus
muscle anteriorly and attachment to the lumbosacral
ligament posteriorly.
2. The lower narrow part of the lateral surface opposite the
inferolateral angle gives attachment to four structures.
From behind forward these are:
(a) Gluteus maximus.
(b) Sacrotuberous ligament.
(c) Sacrospinous ligament.
(d) Coccygeus.
The last structure (i.e., coccygeus) encroaches on the
pelvic surface of the sacrum.
The differences between male and female sacrum are
given in Table 2.3.
Sacral index: It is the ratio between the length and breadth of the
sacrum and is expressed by the formula, breadth ⫻ 100/length.
The sacral index is higher in females than males. The average
sacral index in a female is 116 and in a male it is 112.
It bears an oval facet, which articulates with the body of first
coccygeal vertebra to form the sacrococcygeal joint.
Pelvic Surface
It presents the following particular features (Fig. 2.7B):
1. The median sacral vessels are related to the pelvic surface in the median plane.
2. The sympathetic trunks are related to the pelvic surface
along the medial margins of pelvic sacral foramina.
3. The upper two-and-half sacral vertebrae are related to
the parietal peritoneum except for the site of attachment
of the medial limb of the sigmoid mesocolon.
4. The lower two-and-half vertebrae are related to the rectum, but separated from S3 vertebra by bifurcation of
the superior rectal artery.
5. The piriformis muscle arises from the bodies of middle
three sacral vertebrae in an E-shaped fashion.
6. The pelvic sacral foramina transmit ventral rami of the
corresponding upper four sacral nerves and a branch
from lateral sacral arteries.
Dorsal Surface
It presents the following particular features (Fig. 2.7C):
1. The four dorsal foramina transmit the dorsal rami of the
corresponding upper four sacral spinal nerves.
2. The erector spinae muscle arises from an elongated
U-shaped linear area involving the continuous rows of
the spinous and transverse tubercles.
3. The multifidus arises from the area enclosed by U-shaped
origin of erector spinae. The dorsal rami of upper four
sacral spinal nerves reach the surface by piercing multifidus and erector spinae muscles.
Lateral Surfaces
The auricular surface/facet articulates with the corresponding
auricular surface of the ilium to form sacroiliac joint.
1. The rough area behind the auricular surface gives attachment to strong interosseous sacroiliac ligament.
The ossification of sacrum is not of much clinical interest.
However, students should simply know that since the sacrum
is a composite bone formed by the fusion of five sacral vertebrae, it ossifies by multiple centers.
COCCYX (FIG. 2.8)
The coccyx, or tailbone, is a small, triangular bone formed by
the fusion of four rudimentary coccygeal vertebrae, which
progressively reduce in size from above downward. The tip
of coccyx lies at the level of the upper border of the pubic
symphysis. The coccyx can be palpated in the natal cleft.
1. The word "coccyx" is derived from the Greek word
"cuckoo", a bird. The tailbone was so named because its
shape resembled the bird's beak.
2. Morphologically coccyx represents the tail (tailbone).
3. The number of coccygeal vertebrae may vary from three
to five.
The coccyx is directed downward and forward, making a
continuous curve with the sacrum. It presents the following
Base.
Apex or tip.
Pelvic surface.
Dorsal surface.
Lateral margins.
Table 2.3 Differences between male and female sacrum
Base of sacrum
Width of articular area (body of S1 vertebra)
is more than the length of ala of one side,
i.e., body is broad and alae are narrow
Width of articular area (body of S1 vertebra) is
either equal or less than the length of ala
of one side, i.e., body is narrow and alae are broad
Sacral index
Less (sacrum is relatively longer and narrower)
More (sacrum is relatively shorter and broader)
• Smoothly curved, "C" shaped
(curvature of the pelvic surface is gradual
from above downward)
• Concavity of sacrum is shallower
• Abruptly curved, "J" shaped (lower part of
pelvic surface abruptly curves forward,
curvature being most marked between S1 and
S2 segments and between S3 and S5 segments)
• Concavity of sacrum is deeper
• Extends on to the upper 3 or
3½ of sacral vertebrae
• Relatively larger and less obliquely set
• Concavity of dorsal border of auricular
surface is less marked
• Extends on to the upper 2 or 2½
of sacral vertebrae*
• Relatively smaller and more obliquely set
• Concavity of dorsal border of auricular surface
is more marked
Cornu
Levator ani
Sphincter ani externus
Fig. 2.8 Coccyx: A, pelvic surface; B, dorsal surface.
1. It is formed by the upper surface of the body of the first
coccygeal vertebra.
2. It articulates with the apex of sacrum to form a cartilaginous sacrococcygeal joint.
4. A pair of bony processes called coccygeal cornu project
from the posterolateral aspects of the body of the first
coccygeal vertebra and are connected with the sacral
cornua by the intercornual ligaments.
The fifth sacral nerves after emerging from the sacral
hiatus pass laterally through the interval between the
body of the fifth sacral vertebra and the intercornual
ligaments.
The rudimentary transverse processes of the first coccygeal
vertebrae project laterally and upward from the side of
the base.
1. It is formed by the body of the fourth coccygeal vertebra.
2. It lies about 4 cm behind and above the anal orifice.
3. It provides attachment to sphincter ani externus and
anococcygeal ligaments.
Coccydynia: It is a clinical condition characterized by pain in
the coccygeal region. It occurs due to separation of coccyx
from sacrum following a fall directly on the coccyx.
1. It is related to the rectum.
2. It provides attachment on each side to the coccygeus
muscle in the upper two pieces and levator ani in the
lower two pieces of the coccygeal vertebra.
3. The ganglion impar, where the sympathetic trunks of
two sides meet, lies on the pelvic surface of first coccygeal vertebra deep to the rectum.
4. Anastomosis between the median sacral and inferior lateral sacral arteries and coccygeal body lies on the pelvic
surface distal to ganglion impar.
There are two hip bones, right and left. The hip bone is a large
irregular bone which articulates in front with the corresponding bone of the opposite side. Posteriorly, two hip bones
articulate with the sacrum. The pelvic girdle consists of two
1. It provides origin on each side to gluteus maximus.
2. It provides origin to sphincter ani externus at the tip.
3. It provides attachment to filum terminale on the first
PARTS (FIG. 2.9)
LATERAL MARGINS
Each hip bone consists of three parts: ilium, ischium, and
pubis, which are fused together at a cup-shaped hollow on
the outer aspect of the bone called acetabulum.
They provide attachment to sacrotuberous and sacrospinous
The ilium is the upper expanded part of the hip bone. It
presents the following features:
1. Iliac crest.
2. Three surfaces.
3. Three borders.
The coccyx ossifies from four primary centers, one for each
Gluteal surface
PSIS
Iliac fossa
Iliac tuberosity
Acetabulum
Ischium
Iliopectineal
Upper margin
of pubis
Pubis
Ischial
tuberosity
Ischial tuberosity
Ischial ramus
Body of pubis
Inferior pubic ramus
Fig. 2.9 Hip bone: A, lateral view; B, medial view (ASIS = anterior superior iliac spine, PSIS = posterior superior iliac spine).
Sacropelvic surface
It is the broad, flattened, sinuous ridge forming the upper
limit of the ilium. The highest point of iliac crest lies at the
level of intervertebral disc between L3 and L4 vertebrae.
– The anterior end of iliac crest presents a bony projection
called anterior superior iliac spine, which provides attachment to the lateral end of the inguinal ligament. The
anterior superior iliac spine is easily felt at the lateral end
of the fold of the groin.
– The posterior end of iliac crest also presents a bony projection called posterior superior iliac spine, which lies at
the level of spine of S2 vertebra and marked on the surface
as a small dimple on the lower part of the back.
– The outer lip of iliac crest, about 5 cm behind the anterior
superior iliac spine, presents a tubercle called tubercle of
the iliac crest.
Morphologically, the iliac crest is divided into anterior two-third (ventral segment) and posterior one-third (dorsal segment). The ventral
segment presents an inner lip, an outer lip, and an intermediate area.
The dorsal segment presents inner (medial) and outer (lateral) sloping surfaces.
1. Gluteal surface: It is the outer surface of the ilium. It is
divided into four areas by three gluteal lines. This surface is so named because it provides origin to gluteal
muscles (gluteus maximus, medius, and minimus).
2. Iliac fossa: It is a large, smooth, hollowed-out area on
the anterior part of inner/medial aspect of the ilium.
The upper two-third of this area gives origin to the iliacus
muscle. Posterior to iliac fossa lies the auricular surface
and tuberosity of ilium.
– A curved ridge called arcuate line of ilium separates
the iliac fossa (which forms the bony wall of greater
pelvis) from the part of ilium medial to acetabulum
(which forms the upper part of bony wall of lesser
pelvis).
3. Sacropelvic surface: It is situated behind the medial border
of the ilium and consists of three parts: iliac tuberosity,
auricular surface, and pelvic surface.
(a) The iliac tuberosity is a rough area below the dorsal
segment of the iliac crest.
(b) The auricular surface is ear-shaped articular surface
situated anteroinferior to the iliac tuberosity.
(c) The pelvic surface is situated anteroinferior to the
auricular surface.
1. Anterior border: It extends from anterior superior iliac
spine to the acetabulum.
2. Posterior border: It extends from posterior superior
iliac spine to the upper end of the posterior border of
ischium. It presents posterior inferior iliac spine and
greater sciatic notch.
3. Medial border: It extends from iliac crest to the iliopubic
eminence. It separates iliac fossa from sacropelvic surface.
The pubis is the anteroinferior part of the hip bone and
articulates with the pubis of the opposite hip bone to form
the symphysis pubis. It consists of three parts:
1. Body.
2. Superior ramus.
3. Inferior ramus.
It is flattened anteroposteriorly and presents the following
1. Pubic crest, pubic tubercle, and three surfaces (anterior,
posterior, and medial).
2. The pubic crest is the upper border of the body of pubis.
At the lateral end of the pubic crest is the pubic tubercle.
Superior Ramus
It extends from the body of pubis to the acetabulum above
the obturator foramen. It presents three borders (pectineal
line, obturator crest, and inferior border) and three surfaces
(pectineal, pelvic, and obturator).
– The pectineal line (also called pecten pubis) extends from
pubic tubercle to the iliopubic eminence.
– The obturator crest extends from pubic tubercle to the
acetabular notch.
– The inferior border is sharp and forms the upper margin
of the obturator foramen.
– The pectineal surface is situated between the pectineal
line and obturator crest. It is roughly triangular in shape
and extends from pubic tubercle to the iliopubic eminence.
– The pelvic surface is situated between the pectineal line
and inferior border of the superior ramus.
– The obturator surface is situated between the obturator
crest and inferior border.
Inferior Ramus
It extends from the lower and lateral part of the body of pubis
to fuse with the ramus of ischium to form conjoint ischiopubic
ramus on the medial side of the obturator foramen.
Arcuate line of ilium: It is thick, curved ridge extending from anteroinferior part of auricular surface of ilium to the iliopubic eminence.
Linea terminalis: It is formed by pubic crest, pectin pubis, iliopubic
eminence, arcuate line of ilium, and anterior margin of sacrum.
These bones are united by four joints:
The ischium is the posteroinferior part of the hip bone and
forms the posterior boundary of the obturator foramen. It
consists of two parts:
(a) Two synovial sacroiliac joints (posterosuperolaterally).
(b) Two fibrocartilaginous joints (pubic symphysis anteroinferiorly and sacrococcygeal joint posteroinferiorly).
2. Ramus.
– The body is thick and lies below and posterior to the
acetabulum. It presents two ends (upper and lower), three
borders (anterior, posterior, and lateral), and three surfaces (femoral, dorsal, and pelvic).
– The upper end of the body forms part (two-fifth) of the
acetabulum, whereas its lower end forms ischial tuberosity.
– The posterior border of the body is continuous with the
posterior border of the ilium and presents ischial spine
superior to the tuberosity. The ischial spine projects
posteromedially and separates the lesser sciatic notch of
the ischium inferiorly from the greater sciatic notch on
the posterior border of the ilium.
It is the position in which pelvis lies within the body in erect
posture with the upper margins of the pubic symphysis and
anterior superior iliac spines in the same coronal plane.
To keep the articulated pelvis in anatomical position,
place the pelvis in such a way that above three points touch
the vertical surface.
Ramus
The ramus arises from the lower part of the body and runs
forward, upward, and medially. It presents two surfaces
(anterior and posterior) and two borders (upper and lower).
The upper border forms the boundary of obturator foramen and lower border forms the lateral border of pubic arch.
The hip bone is described in detail in Chapter 21.
1. Posteriorly by sacral promontory and anterior margins
of alae of sacrum.
2. Anteriorly by upper margin of the pubic symphysis and
pubic crest.
3. On either side by arcuate line, iliopectineal eminence,
and pectin pubis.
The pelvis is divided into two parts: greater pelvis and lesser
pelvis by the pelvic inlet (superior pelvic aperture).
The pelvic inlet (also called pelvic brim) is formed
(Fig. 2.10):
GREATER PELVIS (FALSE PELVIS)
The term pelvis is derived from the Latin word, which means
basin.
The bony pelvis is formed by the following four bones
(a) Two hip bones, one on either side.
(b) Sacrum, behind.
(c) Coccyx, behind.
1. It is part of pelvis above the pelvic brim and is formed by
two iliac fossae.
2. The greater pelvis forms a part of posterior abdominal
wall, and contains sigmoid colon and coils of ilium.
LESSER PELVIS (TRUE PELVIS)
It is part of pelvis below the pelvic brim; clinically the term
pelvis is usually applied to the lesser pelvis. The lesser pelvis
is enclosed by sacrum and lower parts of the two hip bones
(below the pelvic inlet).
Components of pelvic brim
Anterior margin of
ala of sacrum
Arcuate line
Iliopectineal eminence
Pecten pubis
Upper margin of pubic symphysis
Fig. 2.10 Female pelvis (red line shows pelvic brim).
Separation of vertebral
arch from vertebral body
Pubic arch
Pelvic outlet
Sacrotuberous
Tip of sacrum
Fig. 2.11 Pelvic outlet.
Table 2.4 Sex differences of bony pelvis
displacement of
L5 vertebral body
False pelvis
Narrow and deep
Wide and shallow
Fig. 2.12 A, Spondylolysis; B, spondylolisthesis.
Transversely oval
True pelvis
(pelvic cavity)
Roomy and shallow
Long and narrow with
smoothly curved
Short and wide with
abruptly curved
near lower end
Subpubic angle
Narrow (70°)
Wide (90°–100°)
The short anteroinferior wall of the lesser pelvis is formed
by the pubic symphysis, whereas its long posterosuperior
wall is formed by the curve of sacrum and coccyx.
The pubic arch, the ischial tuberosities, and the coccyx
form the inferior pelvic aperture of the pelvis with coccyx
and ischial tuberosities being united by the sacrotuberous
ligaments (Fig. 2.11).
The true pelvis is described in detail in Chapter 14.
Table 2.4 enumerates the sex differences of the bony pelvis.
Largest lumbar vertebra
Fifth lumbar (L5)
All the lumbar vertebrae are typical except
Fifth lumbar vertebra which is atypical
Most prominent feature on the dorsal surface of the sacrum
Presence of five vertical crests
Sacred bone
A 65-year-old man visited a hospital and complained of
low backache and pain radiating to the posterolateral
aspect of the thigh. During the physical examination, on
running his fingers along the lumbar spinous processes,
the doctor found an abnormally prominent L5 spinous
process. He suspected spondylolisthesis. The diagnosis
was confirmed by sagittal MRI of the lumbosacral region.
1. What is spondylolysis?
2. What is spondylolisthesis?
3. In normal conditions which parts of the fifth lumbar
vertebra and sacrum interlock with each other.
1. A defect allowing part of vertebral arch of L5 vertebra
to be separated from the body. In this condition there
is separation of vertebral body from the part of vertebral arch bearing the inferior articular processes
(Fig. 2.12A).
2. When the defect is bilateral (vide supra), the body of
L5 vertebra slides anteriorly on the sacrum so that it
overlaps the sacral promontory. This condition is
called spondylolisthesis (Fig. 2.12B).
3. Normally inferior articular processes of L5 vertebra
interlock with the articular processes of the sacrum.
Fascia transversalis
– Extent
– Important features
Surface landmarks
– Bony landmarks
– Soft tissue landmarks
– Abdominal planes
Layers of the anterior abdominal wall
– Skin
– Superficial fascia
Muscles of the anterior abdominal wall
define the boundaries of anterior abdominal wall
enumerate the layers of anterior abdominal wall
define the umbilicus and discuss its anatomical,
embryological, and clinical significance
present a brief account of superficial fascia of anterior
abdominal wall
describe the anatomical basis of caput medusae and
formation of thoraco-epigastric vein
discuss the attachments, nerve supply, and functions of
muscles of anterior abdominal wall
define the rectus sheath, and discuss its formation and
importance in surgical incisions
Flat muscles
Structures derived from flat muscles
Vertical muscles
Functions of the anterior abdominal muscles
Rectus sheath
• Deep nerves of the anterior abdominal wall
Lower five intercostal nerves
Subcostal nerve
Iliohypogastric nerve
Ilioinguinal nerve
Deep arteries of the anterior abdominal wall
Superior epigastric artery
Musculophrenic artery
Inferior epigastric artery
Deep circumflex iliac artery
The anterior abdominal wall covers a large area in the body.
It is bounded above by the xiphoid process, and right and left
costal margins; below by the anterior part of the iliac crest,
fold of groin, pubic tubercle, pubic crest, and pubic symphysis; and on each side it is separated from the posterior
abdominal wall by the midaxillary line.
The anatomy of anterior abdominal wall is clinically very
important due to the following reasons:
1. The physical examination of the abdomen is mostly performed through the anterior abdominal wall.
2. Access to the abdomen and its contents is usually obtained
through the incision in the anterior abdominal wall.
3. Abdominal hernias mostly occur through the anterior
to reach the sternum. The costal margins run upward and
medially toward the side of the xiphoid process and enclosed
between them is the infrasternal (subcostal) angle. The costal
margin reaches its lowest level in the midaxillary line.
XIPHOID PROCESS
It lies at the apex of subcostal angle and its apex is sometimes
bent forward and hence easily palpable beneath the skin. The
xiphoid process lies at the level of T9 vertebra.
It forms the lower limit of the abdominal wall at the side and
can be traced forward to the anterior superior iliac spine. About
5 cm behind the anterior superior iliac spine a prominent
tubercle of iliac crest can be felt on the outer lip of the crest.
SOFT TISSUE LANDMARKS (FIGS 3.2 AND 3.3)
The surface landmarks such as costal margins, umbilicus,
anterior superior iliac spine, iliac tubercle, linea semilunaris,
etc., are important guides in orienting the clinician to the
location of the viscera in the abdominal cavity.
GROOVE OF GROIN
It extends downward and medially from anterior superior iliac
spine to the pubic tubercle. It overlies the inguinal ligament.
It is placed at the junction of the anterior abdominal wall
and the front of the thigh.
MIDLINE FURROW/GROOVE
BONY LANDMARKS (FIG. 3.1)
COSTAL MARGINS
The cartilages of the 7th, 8th, 9th, and 10th ribs form the
costal margins. The 7th costal cartilage is the lowest cartilage
It is a linear furrow, which extends from the xiphoid process
above to the pubic symphysis below. It corresponds to the
linea alba – a tendinous raphe, which separates the two rectus muscles from each other. The midline linear furrow
divides the anterior abdominal wall into right and left halves.
Transpyloric plane (Addison's plane)
Subcostal plane
Transtubercular plane
Tubercle of iliac crest
Anterior superior iliac spine
Inguinal ligament
Tip of coccyx
Fig. 3.1 Bony landmarks of the abdomen.
Pubic tubercle
Pubic crest
Pubic symphysis
Tip of 9th costal cartilage
Linea alba
Linea semilunaris
Linea transversalis
Linea gravidarum
(white lines of pregnancy)
Inguinal line (Poupart's line)
Holden's line
Line of Venus
Fig. 3.2 Visible skin creases/lines, seen on the front of abdomen.
Tip of 9th
costal cartilage
McBurney's line
(spino-umbilical line)
Anterior superior
Tendinous
McBurney's point
inguinal ring
Spermatic cord
Fig. 3.3 Bony and soft tissue landmarks of the abdomen and their relationship with gallbladder and spermatic cord.
TRANSVERSE FURROWS
It is an irregular, depressed or elevated scarred area in the
linear midline furrow, a little below its midpoint.
Two or three transverse furrows may sometimes be seen
crossing the rectus abdominis muscle and corresponds to the
tendinous intersections of the muscle.
It is a curved furrow, which extends from tip of the 9th costal
cartilage to the pubic tubercle. It lies few centimeters from
the median furrow and corresponds to the lateral margin of
the rectus abdominis.
It is a semilunar line with concavity facing upward, seen
mostly in females on the anterior abdominal wall between
the umbilicus and pubic symphysis.
ABDOMINAL PLANES
TRANSPYLORIC PLANE
It is an imaginary horizontal plane which passes through the
midpoint of the line joining the jugular (suprasternal) notch to
the symphysis pubis. It lies about one hand's breadth below the
xiphisternal joint. Anteriorly it passes through the tip of the
9th costal cartilage and posteriorly through the lower border
of the body of L1 vertebra.
It is an imaginary horizontal plane, which passes immediately below the costal margins. It passes anteriorly through
the lowest borders of costal cartilages of the 10th rib, and
posteriorly through the body of L3 vertebra.
TRANSUMBILICAL PLANE
It is a transverse plane that passes through the umbilicus (or
navel) and lies at the level of intervertebral disc between the
L3 and L4 vertebrae.
INTERTUBERCULAR PLANE
It is an imaginary horizontal plane which joins the tubercles
of the iliac crests. It is palpable 5 cm posterior to the anterior
superior iliac spines and passes through the upper part of the
body of L5 vertebra.
RIGHT AND LEFT VERTICAL PLANES (ALSO CALLED
MIDCLAVICULAR PLANES)
1. The skin of the anterior abdominal wall is thinner and
more sensitive than the skin of the posterior abdominal
2. The cleavage lines (Langer's lines) in the anterior
abdominal wall run horizontally. Therefore, the abdominal incisions preferably should be given horizontally. So
that wounds heal with invisible linear scars (Fig. 3.4).
3. The skin of the anterior abdominal wall presents in the
anterior midline a depressed area—the umbilicus made
up of cicatricial tissue, which represents the attachment
of fetal end of the umbilical cord.
4. In the multiparous women, the lower part of the anterior abdominal wall presents a number of irregularly
branched white lines called striae gravidarum. They
occur due to degenerative fibrosis of subcutaneous fat
because of undue stretching of the anterior abdominal
wall by the gravid uterus.
The umbilicus is of great anatomical, embryological, and
clinical importance hence discussed in detail in the following
text.
1. The umbilicus is the most obvious feature of the anterior
2. It is in fact a normal puckered scar in the abdominal wall
representing the site of attachment of the umbilical cord
in the fetus.
They pass from the midpoint of the clavicle superiorly to the
point midway between the anterior superior iliac spine and
the pubic symphysis inferiorly, i.e., midinguinal point.
The anterior abdominal wall is firm and elastic. It consists of
eight layers. From superficial to deep, these are as follows:
Superficial fascia.
External oblique muscle.
Internal oblique muscle.
Transversus abdominis muscle.
Fascia transversalis.
Extraperitoneal tissue.
Parietal layer of peritoneum.
The deep fascia is absent in the anterior abdominal wall to allow the
bulging of the abdominal wall as after taking meals, during pregnancy, etc. It is also absent in the penis, scrotum, and perineum.
Langer's lines
Vertical incision
(across Langer's lines)
Wide scar upon healing
Horizontal incision
(Parallel to Langer's lines)
Linear scar upon healing
Fig. 3.4 Cleavage (Langer's) lines/crease lines on the anterior
The position of umbilicus is variable:
Thus, there are four important embryological remnants at
the umbilicus (Fig. 3.5).
1. In adult, it lies at the level of intervertebral disc between
2. In newborn, it is slightly at a lower level due to poorly
developed pelvic region.
3. In old age, it comes down to lower level due to diminished
tone of the abdominal muscles.
Anatomical Significance
1. The level of umbilicus serves as water-shed line for
venous and lymphatic drainage. The venous blood and
lymph flow upward above the level of the umbilicus and
downward below the level of the umbilicus.
2. It indicates the level of T10 dermatome, i.e., skin around
the umbilicus is supplied by the 10th spinal segment.
3. It is one of the important sites of portacaval anastomosis.
Although the umbilicus is a scar in the anterior abdominal
wall, it is of immense cosmetic value particularly in the
females. Therefore, the surgical incision should never be
given across it.
The skin around the umbilicus is supplied by T10 spinal
segment. Therefore, visceral pain of appendicitis is referred
to the umbilicus (note the appendix is supplied by T10
spinal segment).
Embryological Significance
1. It is the meeting point of four folds of embryonic plate
(e.g., two lateral folds, head fold, and tail fold).
2. In embryonic life, a defect exists in the linea alba at this
site called umbilical ring, which provides passage to the
following structures:
(a) The midgut loop herniates into the umbilical cord
during fifth to tenth weeks of IUL (intrauterine life)
but returns back to the abdominal cavity during
tenth to twelfth week of intrauterine life.
(b) The two endodermal tubes (allantois and vitellointestinal duct) project into the umbilical cord. The
allantois is a diverticulum of endodermal cloaca. Its
proximal part gives rise to the urinary bladder and
distal part to urachus. The vitello-intestinal duct is a
diverticulum of midgut extending from the distal
part of ileum to the umbilicus. Sometimes its proximal part persists as Meckel's diverticulum.
(c) Umbilical vessels (two arteries, one vein) pass to and
fro between umbilical cord and placenta. The remnants of umbilical arteries are present in adult as
medial umbilical ligament and remnant of umbilical
vein as ligamentum teres.
Ligamentum teres (remnant of left umbilical vein).
Two medial umbilical ligaments (remnant of umbilical
arteries).
Urachus (remnant of allantois).
Congenital anomalies: The important congenital anomalies of
the umbilicus are fistulae and exomphalos.
(a) Fecal fistula: Failure of vitello-intestinal duct to obliterate
results in fecal fistula at the umbilicus.
(b) Urinary fistula: Failure of urachus to obliterate leads to
urinary fistula at the umbilicus.
(c) Exomphalos (or omphalocele): Failure of midgut loop to
return in the abdominal cavity result in the exomphalos.
Since the intestine protrude through a defect in all layers of
the abdominal wall at umbilical ring a thin transparent
membrane—the amnion—covers it.
In congenital umbilical hernia the intestine protrudes
through the umbilicus due to weakness of umbilical scar,
hence it is covered by the peritoneum.
The umbilicus is therefore considered as hotbed of
embryology by the clinicians.
For details refer to Clinical and Surgical Anatomy by the
author.
SUPERFICIAL FASCIA
The superficial fascia contains a variable amount of fat, maximum in the lower half of the anterior abdominal wall. The
anterior abdominal wall is the major site of fat accumulation
especially in the females leading to obesity.
Above the level of the line joining the two anterior superior iliac spines the superficial fascia consists of a single layer
Ligamentum teres
(remnant of left
umbilical vein)
Medial umbilical
ligament (remnant of
umbilical artery)
Median umbilical
ligament/urachus
(remnant of allantois)
Fig. 3.5 Four embryological remnants at the umbilicus.
Urogenital diaphragm
Scarpa's fascia
Perineal membrane
Fascia of penis
perineal pouch
Colles' fascia
Dartos muscle
Fig. 3.6 Extent of the membranous layer of superficial fascia of the abdomen (Scarpa's fascia): A, as seen in anterior view;
B, as seen in sagittal section.
but below this line it consists of two layers (Fig. 3.6): (a) a
superficial fatty layer (Camper's fascia) and (b) a deep membranous layer (Scarpa's fascia). The space between the two layers contains superficial, epigastric, circumflex iliac, external
pudendal vessels, and superficial inguinal lymph nodes.
CAMPER'S FASCIA (SUPERFICIAL FATTY LAYER)
This superficial fatty layer of superficial fascia of the abdomen
is continuous with the superficial fascia of the adjoining
areas of the body. Over the penis, it is devoid of fat, and in
the scrotum, it is replaced by an involuntary dartos muscle.
which also stretches across the pubic arch. The space
between the perineal membrane and Colles' fascia is
known as superficial perineal pouch.
• The line of attachment of Scarpa's fascia with the fascia latae is
marked on the surface by Holden's line, which begins a little lateral
to the pubic tubercle and extends laterally for about 8 cm.
• A potential space exists in the anterior abdominal wall between
Scarpa's fascia and aponeurosis of the external oblique. It is termed
superficial inguinal space.
This deep membranous layer of superficial fascia of the
abdomen is made up of elastic type of fibrous tissue.
Students must remember its following features:
The Scarpa's fascia bears two important clinical relations:
1. In the midline, it is attached to the linea alba.
2. On each side, it is separated from underlying external
oblique muscle by a layer of loose areolar tissue, which
disappears superiorly and toward the median plane.
3. Below,
(a) it crosses the inguinal ligament and gets attached to
the fascia latae of the thigh immediately below and
parallel to the ligament.
(b) it is prolonged over the penis to enclose it up to the
base of the glans and forms the fascia of the penis
(Buck's fascia).
(c) it covers the scrotum where it is replaced by dartos
muscle and then continue with the superficial fascia
of perineum—the Colles' fascia. The Colles' fascia
stretches across the pubic arch and is attached to
the posterior edge of the urogenital diaphragm/
posterior border of the perineal membrane,
It serves as a firm unit for suturing the superficial fascia
during closure of the anterior abdomen/perineum after
abdominal or pelvic surgery.
The Scarpa's fascia is continuous with the superficial perineal fascia (Colles' fascia) of the perineum and attached to
the fascia lata of thigh below the inguinal ligament. This
attachment corresponds on the surface as Holden's line.
Therefore, if male urethra is ruptured in the perineum, the
urine collects first in the superficial pouch of perineum and then
extravasate on to the anterior abdominal wall inferior to the
umbilicus in the superficial inguinal space (Fig. 3.7).
The presence of urine in this confined space where Scarpa's
fascia is attached makes the clinician to suspect urethral
rupture due to trauma. Clinically rupture of the urethra in the
perineum presents as follows:
Swollen perineum.
Swollen scrotum.
Swollen penis.
Swollen lower part of abdominal wall.
Collection of
extravasated urine
Buck's fascia
of urethra
Dartos
Fig. 3.7 Rupture of urethra in perineum and collection of
extravasated urine in superficial perineal pouch and superficial
inguinal space.
Iliohypogastric
nerve (L1)
Ilioinguinal
Fig. 3.8 Cutaneous nerves of the anterior abdominal wall.
CUTANEOUS NERVES (FIG. 3.8)
The skin of the anterior abdominal wall is almost entirely
supplied by the lower six intercostal and subcostal nerves.
Only the most inferior part is supplied by the first lumbar
nerve through the iliohypogastric and ilioinguinal nerves.
Anterior Cutaneous Branches
The anterior cutaneous nerves (seven in number) are derived
from the lower five intercostal, subcostal, and iliohypogastric
nerves. They pierce the anterior wall of the rectus sheath a
short distance away from the median plane, and divide into
medial and lateral branches to supply the skin.
The cutaneous branches from T7 to T10 are arranged in a
sequence with T7 near the xiphoid process and T10 close to
the umbilicus. The anterior cutaneous branch of iliohypogastric nerve emerges 2.5 cm above the superficial inguinal ring.
The ilioinguinal nerve lacks the lateral cutaneous branch and
its anterior cutaneous branch passes through the superficial
inguinal ring and supplies skin on the upper medial aspect of
the thigh, and skin of the scrotum or labium majus.
The dermatomes of the anterior abdominal wall are shown
in Figure 3.9.
Lateral Cutaneous Branches
1. The lateral cutaneous branches from lower two intercostal nerves emerge through the external intercostal
muscle and divide into a large anterior and small posterior branches to supply the skin.
2. The lateral cutaneous branches of subcostal and iliohypogastric nerves appear close to the iliac crest and descend
over it to supply the skin in the upper anterior part of the
gluteal region.
Fig. 3.9 Dermatomes on the anterior abdominal wall.
CUTANEOUS ARTERIES (FIG. 3.10)
1. Cutaneous branches of superior and inferior epigastric
arteries accompany the anterior cutaneous nerves.
2. Cutaneous branches of posterior intercostal arteries
accompany the lateral cutaneous nerves.
3. Superficial branches of femoral artery (superficial
external pudendal, superficial epigastric, and superficial
circumflex iliac) supply the skin of the abdomen below
the umbilicus.
Internal thoracic
Musculophrenic
Superior epigastric
Posterior intercostal
Inferior epigastric
Superficial epigastric
Deep circumflex
iliac artery
Superficial circumflex
Superficial external
pudendal artery
Fig. 3.10 Arteries of the anterior abdominal wall.
(a) The superficial external pudendal artery runs medially and passes in front of the spermatic cord to supply the scrotum (or labium majus) and penis.
(b) The superficial epigastric artery runs superomedially
across the inguinal ligament up to the umbilicus.
(c) The superficial circumflex iliac artery runs laterally
below the inguinal ligament toward the anterior
superior iliac spine to supply the skin of inguinal
Axillary vein
Lateral thoracic
CUTANEOUS (SUPERFICIAL) VEINS (FIG. 3.11)
They accompany the cutaneous arteries and drain as follows:
1. Below the umbilicus they run downward and drain into
the great saphenous vein in the groin and thus eventually in the inferior vena cava.
2. Above the umbilicus they run toward the axilla and
drain into the axillary vein and thus eventually in the
superior vena cava.
Small veins from the umbilicus run along the ligamentum teres to
drain into the portal vein.
Great saphenous
Fig. 3.11 Superficial veins of the anterior abdominal wall.
The superficial veins of the anterior abdominal wall
anastomose freely with each other and with the small veins
(paraumbilical veins) which drain the umbilicus.
In portal vein obstruction (Fig. 3.12A), when the venous
drainage through the liver is obstructed, the backflow
of blood may occur through paraumbilical veins toward the
umbilicus. As a result, the paraumbilical veins and superficial veins around the umbilicus become grossly distended
and tortuous. They radiate out from the umbilicus like
spokes of a wheel, producing a clinical sign called caput
medusae. This condition is so called because of its resemblance to the serpents on the head of the Medusa, a mythical lady in Greek mythology.
In caval obstruction (Fig. 3.12B) (i.e., obstructions of superior
and inferior vena cavae), the thoraco-epigastric vein connecting the saphenous and axillary veins opens up.
In superior vena cava obstruction, blood in the thoracoepigastric vein flows downward whereas in the inferior vena
cava obstruction it flows upward.
Thoraco-epigastric
Caput medusae
Fig. 3.12 Subcutaneous venous collateral circulation: A, portal obstruction; B, caval obstruction (superior vena cava obstruction on
the right side and inferior vena cava obstruction on the left side).
The thoraco-epigastric vein is formed by the anastomosis of lateral thoracic vein (a tributary of axillary vein) with the superficial epigastric
vein (a tributary of great saphenous vein).
Axillary
CUTANEOUS (SUPERFICIAL) LYMPH VESSELS (FIG. 3.13)
The lymph from the skin of the abdominal wall is drained
into axillary and superficial inguinal lymph nodes as follows:
1. Above the umbilicus, the lymph vessels run upward to
drain into the axillary lymph nodes (anterior/pectoral
group).
2. Below the umbilicus, the lymph vessels run downward and
laterally to drain into the superficial inguinal lymph nodes.
The infection or malignant tumor of the skin in the lower part
of the anterior abdominal wall may cause swelling in the groin
due to enlargement of superficial inguinal lymph nodes, and
similar lesions in the upper part of the abdomen may produce
swelling in the axilla due to enlargement of axillary lymph nodes.
MUSCLES OF THE ANTERIOR
The anterior abdominal wall consists of five pairs of muscles—
three pairs of flat muscles and two pairs of vertical muscles.
Superficial inguinal
Fig. 3.13 Superficial lymphatics of the anterior abdominal
On either side of midline, the three flat muscles are external oblique, internal oblique, and transversus abdominis; and
two vertical muscles are rectus abdominis and pyramidalis.
The three flat muscles are fleshy posterolaterally and
aponeurotic anteromedially. The aponeuroses of these muscles pass toward the midline to enclose the rectus abdominis
and pyramidalis, and then fuse with each other and with the
aponeuroses of the muscles of the opposite side in the
median fibrous raphe extending from the xiphoid process to
the pubic symphysis, forming the linea alba.
The insertion occurs as follows:
If you place your hands on either side of your abdomen with fingertips
just touching in the midline, the palms of your hands lie mainly over
the fleshy portions of flat muscles and fingers over their aponeuroses.
Thus, anterior part of the abdominal wall is mostly aponeurotic except
for the rectus abdominis and pyramidalis, which are enclosed within
the aponeurosis.
The three anterolateral flat muscles (external oblique, internal oblique, and transversus abdominis) form three distinct
layers in the anterior abdominal wall, similar to those in the
intercostal space, and as in the intercostal space the neurovascular structures lie between the internal oblique and
transversus abdominis muscles.
EXTERNAL OBLIQUE MUSCLE (FIG. 3.14)
The external oblique muscle arises from eight fleshy slips
from the outer surfaces (the middle of the shaft) of lower
eight ribs.
Most of the fleshy fibers run downward, forward, and medially in the same direction as the fingers do when you put the
hand inside the side pocket of your pantaloon.
The most posterior fibers pass vertically downward to be
inserted on to the outer lip of the anterior two-third of the
iliac crest. The posterior border of muscle is thus free.
2. The remaining fibers pass downward, forward, and medially to end in a broad aponeurosis, which is inserted into
the linea alba extending from the xiphoid process to the
pubic symphysis.
(a) The upper border of the aponeurosis is free and overlapped by the fibers of pectoralis major muscle.
(b) The lower border of the aponeurosis is free and
jumps from anterior superior iliac spine to the
pubic tubercle bridging across the muscles, nerves,
and vessels that enter the thigh from the abdomen.
The free lower border of the aponeurosis is thickened and
rolled inward to form the inguinal ligament.
• The upper four slips of origin interdigitate with the slips of serratus
anterior and lower four slips with the slips of latissimus dorsi.
• Above the pubic symphysis the aponeurosis presents a triangular
gap called superficial inguinal ring.
• Posterior-free border of muscle forms the anterior boundary of the
lumbar triangle.
• The lower-free border of aponeurosis forms the inguinal ligament.
• Muscle fibers become aponeurotic approximately at the midclavicular line medially and spino-umbilical line (line extending from the
umbilicus to the anterior superior iliac spine) inferiorly.
Posterior-free
Aponeurosis
Line of demarcation
between muscular and
aponeurotic parts of
the muscle
Superficial inguinal ring
formed by the lower-free border
Fig. 3.14 External oblique muscle.
Nerve Supply
By anterior rami of lower six thoracic spinal nerves (T7–T12).
INTERNAL OBLIQUE MUSCLE (FIG. 3.15)
3. Remaining fibers run upward, forward, and medially,
and end in a broad aponeurosis, which is inserted into the
7th, 8th, and 9th costal cartilages, and linea alba extending from the xiphoid process to the pubic symphysis.
This muscle is smaller and thinner than the external oblique.
It lies deep to external oblique and its fibers are oriented at
right angles to those of external oblique.
Internal oblique is supplied by the lower six thoracic
(T7–T12), iliohypogastric, and ilioinguinal nerves (L1).
It arises from before backward as follows:
TRANSVERSUS ABDOMINIS MUSCLE (FIG. 3.16)
1. Lateral two-third of the upper surface of the inguinal
ligament.
2. Anterior two-third of the iliac crest (intermediate area).
3. Thoraco-lumbar fascia.
Most of the fibers run upward, forward, and medially at right
angle to that of external oblique (as your fingers do when
you place your hand in front of the chest).
1. Most posterior fibers ascend vertically upward and
inserted by fleshy fibers into the lower border of lower
3rd or 4th ribs and their costal cartilages.
2. The fleshy fibers arise from inguinal ligament arch over
the inguinal canal and its contents, and then descend to
be inserted on to the pubic tubercle and pecten pubis.
These fibers fuse with the tendinous fibres of the transversus abdominis muscle to form conjoint tendon
which is inserted into the pubic crest and medial part of
the pecten pubis.
The transversus abdominis muscle is the innermost of three
flat abdominal muscles. It is narrow because the direction of
most of its fibers is horizontal/transverse.
It arises from:
1. Anterior two-third of the iliac crest (inner lip).
2. Lateral one-third of the upper surface of the inguinal
4. Inner surfaces of the lower six ribs and their costal
cartilage.
The muscle is inserted as follows:
1. Inguinal fibers arch backward forming the roof of the
inguinal canal, and then turn downward and medially
forming an aponeurosis which joins similar aponeurosis
of internal oblique to form conjoint tendon, through
which it is inserted into the pubic crest and medial part
of pecten pubis.
Thoraco-lumbar
Aponeurosis forming
anterior wall as well as
posterior wall of rectus
anterior wall of
conjoint tendon
Fig. 3.15 Internal oblique muscle.
1. Lower six costal cartilages
(inner surface)
1. Linea alba
2. Thoraco-lumbar fascia
3. Anterior 2/3rd of the
iliac crest (inner lip)
4. Lateral 1/3rd of
Pectineal line
2. Pubic crest
3. Pectineal line
Fig. 3.16 Origin and insertion of transversus abdominis muscle.
2. Remaining fibers end in a broad aponeurosis through
which it is inserted into the linea alba extending from
the xiphoid process to the pubic symphysis.
By the lower six thoracic nerves (T7–T12), and the iliohypogastric and ilioinguinal nerves (L1).
An important fact for students to remember is that external oblique
lies superficial to the lower ribs, internal oblique attaches to the
costal margin, and transversus abdominis muscle lies deep to the
lower ribs.
and medial part of the pectineal line (pecten pubis). The
important features of the conjoint tendon are as follows:
1. It forms the medial half of the posterior wall of the
inguinal canal and strengthens the anterior abdominal
wall of the canal opposite the superficial inguinal ring.
2. Medially, it blends with the anterior wall of the rectus
sheath.
3. Laterally, it may extend occasionally up to the interfoveolar ligament, a thickening in the fascia transversalis along
the medial border of deep inguinal ring. The interfoveolar ligament extends from the lower border of transversus abdominis to the superior ramus of the pubis.
The weakening of conjoint tendon due to old age or injury of iliohypogastric and ilioinguinal nerves predisposes the occurrence of direct
inguinal hernia.
The structures derived from flat muscles are as follows:
1. Inguinal ligament.
2. Conjoint tendon.
3. Cremaster muscle.
It is the lower-free border of external oblique aponeurosis
stretching between anterior superior iliac spine and pubic
tubercle (for details see p. 50).
CONJOINT TENDON (FALX INGUINALIS)
It is formed by the fusion of lower aponeurotic fibers of internal oblique and transversus abdominis muscles which arches
over the spermatic cord and is attached on to the pubic crest
CREMASTER MUSCLE (FIG. 3.17)
The cremaster mu


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Quick assists provide fast access to code refactoring operations.
To see the list of available Quick Assist Proposals simply press Ctrl+1.
Use the Up and Down arrows to select a proposal, then press Enter to apply it.
The proposals depend on the editing context.
For example, to split a function into 'extern' prototype and implementation, place the editor cursor on the function declaration and press Ctrl+1.
To extract a block of actions to a new method, select the block and press Ctrl+1.
Tip: Right-click in the editor and go to the Refactor submenu to see all refactoring operations.


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Beeswax is a wonderful, malleable and beneficial product that has a wide array of possible uses. This attractive book has a lot to offer for the intermediate do-it-yourselfer. In her debut book, businesswoman Ahnert provides an excellent introduction and solid technique instruction to make candles, lotions, and soaps with beeswax. The joint and muscle cream is unusual, as is the herb-infused oil base. In comparison, the section on wax candles seems perfunctory, and the use of wax in art and fabric applications is weak. Some ingredients and tools are very specialized and not available in neighborhood craft stores. VERDICT Go elsewhere for batik or candle making. The true strength of this book is its instructions for making homemade body products. While similar in coverage to Leeann Coleman and Jayne Barnes's Honey Crafting, Ahnert's book provides better body products and more detailed technical instruction. Strongly recommended.


text:
package consulapi

// Status can be used to query the Status endpoints
type Status struct {
	c *Client
}

// Status returns a handle to the status endpoints
func (c *Client) Status() *Status {
	return &Status{c}
}

// Leader is used to query for a known leader
func (s *Status) Leader() (string, error) {
	r := s.c.newRequest("GET", "/v1/status/leader")
	_, resp, err := requireOK(s.c.doRequest(r))
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var leader string
	if err := decodeBody(resp, &leader); err != nil {
		return "", err
	}
	return leader, nil
}

// Peers is used to query for a known raft peers
func (s *Status) Peers() ([]string, error) {
	r := s.c.newRequest("GET", "/v1/status/peers")
	_, resp, err := requireOK(s.c.doRequest(r))
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	var peers []string
	if err := decodeBody(resp, &peers); err != nil {
		return nil, err
	}
	return peers, nil
}

redpajama_set_name: RedPajamaGithub


Maximize 529 tax benefits by opening self/spouse accounts?
Hi, I'm a GA resident, opening 529 accounts for each of 3 kids. State will give tax deduction for up to $4000 of contributions per beneficiary if married filing jointly.
My question is, can I open accounts for myself and wife and contribute to get additional tax break and then transfer that money to one of the kids' accounts when the time comes?
Also, any rule for how long the money has to be in the account before it can be transferred?


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