What is the largest artery in the human body?
Artery of Adamkiewicz
In human anatomy, the artery of Adamkiewicz (also arteria radicularis magna) is the largest anterior segmental medullary artery. It typically arises from a left posterior intercostal artery at the level of the 9th to 12th intercostal artery, which branches from the aorta, and supplies the lower two thirds of the spinal cord via the anterior spinal artery.
Vein
The vessels that remove the deoxygenated blood from the heart muscle are known as cardiac veins. These include the great cardiac vein, the middle cardiac vein, the small cardiac vein, the smallest cardiac veins, and the anterior cardiac veins. Coronary veins carry blood with a poor level of oxygen, from the myocardium to the right atrium. Most of the blood of the coronary veins returns through the coronary sinus. The anatomy of the veins of the heart is very variable, but generally it is formed by the following veins: heart veins that go into the coronary sinus: the great cardiac vein, the middle cardiac vein, the small cardiac vein, the posterior vein of the left ventricle, and the vein of Marshall. Heart veins that go directly to the right atrium: the anterior cardiac veins, the smallest cardiac veins (Thebesian veins).
Vertebral artery
Inside the skull, the two vertebral arteries join to form the basilar artery at the base of the pons. The basilar artery is the main blood supply to the brainstem and connects to the Circle of Willis to potentially supply the rest of the brain if there is compromise to one of the carotids. At each cervical level, the vertebral artery sends branches to the surrounding musculature via the anterior spinal arteries.
The vertebral artery may be divided into four parts:
Great arteries
The great arteries originate from the aortic arches during embryonic development. The aortic arches start as five pairs of symmetrical vessels connecting the heart with the dorsal aorta but then undergo a significant remodelling, in which some of these vessels regress (aortic arches 1 and 2), the 3rd pair of arches contribute to form the common carotids, the right 4th will contribute to the base and central part of the right subclavian artery, while the left 4th will form the central portion of the aortic arch.
Trabecular arteries
Each of the larger branches of the artery supplies chiefly that region of the organ in which the branch ramifies, having no anastomosis with the majority of the other branches.
Hemodynamics
Immediately following the arterioles are the capillaries. Following the logic observed in the arterioles, we expect the blood pressure to be lower in the capillaries compared to the arterioles. Since pressure is a function of force per unit area, ("P" = "F"/"A"), the larger the surface area, the lesser the pressure when an external force acts on it. Though the radii of the capillaries are very small, the network of capillaries have the largest surface area in the vascular network. They are known to have the largest surface area (485 mm^2) in the human vascular network. The larger the total cross-sectional area, the lower the mean velocity as well as the pressure.
Artery
The anatomy of arteries can be separated into gross anatomy, at the macroscopic level, and microanatomy, which must be studied with a microscope. The arterial system of the human body is divided into systemic arteries, carrying blood from the heart to the whole body, and pulmonary arteries, carrying deoxygenated blood from the heart to the lungs.
Anastomosis
In circulatory anastomoses, many arteries naturally anastomose with each other; for example, the inferior epigastric artery and superior epigastric artery, or the anterior and/or posterior communicating arteries in the Circle of Willis in the brain. The circulatory anastomosis is further divided into arterial and venous anastomosis. Arterial anastomosis includes actual arterial anastomosis (e.g., palmar arch, plantar arch) and potential arterial anastomosis (e.g. coronary arteries and cortical branch of cerebral arteries). Anastomoses also form alternative routes around capillary beds in areas that don't need a large blood supply, thus helping regulate systemic blood flow.
Artery
The capillaries are the smallest of the blood vessels and are part of the microcirculation. The microvessels have a width of a single cell in diameter to aid in the fast and easy diffusion of gases, sugars and nutrients to surrounding tissues. Capillaries have no smooth muscle surrounding them and have a diameter less than that of red blood cells; a red blood cell is typically 7 micrometers outside diameter, capillaries typically 5 micrometers inside diameter. The red blood cells must distort in order to pass through the capillaries.
Body cavity
Anatomical structures are often described in terms of the cavity in which they reside. The body maintains its internal organization by means of membranes, sheaths, and other structures that separate compartments. The dorsal (posterior) cavity and the ventral (anterior) cavity are the largest body compartments. These cavities contain and protect delicate internal organs, and the ventral cavity allows for significant changes in the size and shape of the organs as they perform their functions. The lungs, heart, stomach, and intestines, for example, can expand and contract without distorting other tissues or disrupting the activity of nearby organs.
Ophthalmic artery
The next branch of the OA is the lacrimal artery, one of the largest, arises just as the OA enters the orbit and runs along the superior edge of the lateral rectus muscle to supply the lacrimal gland, eyelids and conjunctiva.
Aorta
The aorta is an elastic artery, and as such is quite distensible. The aorta consists of a heterogeneous mixture of smooth muscle, nerves, intimal cells, endothelial cells, fibroblast-like cells, and a complex extracellular matrix. The vascular wall consists of several layers known as the tunica externa, tunica media, and tunica intima. The thickness of the aorta requires an extensive network of tiny blood vessels called vasa vasorum, which feed the tunica externa and tunica media outer layers of the aorta. The aortic arch contains baroreceptors and chemoreceptors that relay information concerning blood pressure and blood pH and carbon dioxide levels to the medulla oblongata of the brain. This information is processed by the brain and the autonomic nervous system mediates the homeostatic responses.
Heart
The largest part of the heart is usually slightly offset to the left side of the chest (though occasionally it may be offset to the right) and is felt to be on the left because the left heart is stronger and larger, since it pumps to all body parts. Because the heart is between the lungs, the left lung is smaller than the right lung and has a cardiac notch in its border to accommodate the heart.
The heart is cone-shaped, with its base positioned upwards and tapering down to the apex. An adult heart has a mass of 250–350 grams (9–12 oz). The heart is often described as the size of a fist: 12 cm (5 in) in length, 8 cm (3.5 in) wide, and 6 cm (2.5 in) in thickness, although this description is disputed, as the heart is likely to be slightly larger. Well-trained athletes can have much larger hearts due to the effects of exercise on the heart muscle, similar to the response of skeletal muscle.
Inferior mesenteric artery
In human anatomy, the inferior mesenteric artery, often abbreviated as IMA, is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the left colic (or splenic) flexure to the upper part of the rectum, which includes the descending colon, the sigmoid colon, and part of the rectum. Proximally, its territory of distribution overlaps (forms a watershed) with the middle colic artery, and therefore the superior mesenteric artery. The SMA and IMA anastomose via the marginal artery of the colon (artery of Drummond) and via Riolan's arcade (also called the "meandering artery", an arterial connection between the left colic artery and the medial colic artery). The territory of distribution of the IMA is more or less equivalent to the embryonic hindgut.
Coronary artery ectasia
Coronary artery ectasia is a rare disease that occurs in only 0.3-4.9% of people in North America. Coronary artery ectasia is characterized by the enlargement of a coronary artery to 1.5 times or more than its normal diameter. The disease is commonly asymptomatic and is normally discovered when performing tests for other conditions such as coronary artery disease, stable angina and other acute coronary syndromes. Coronary artery ectasia occurs 4 times more frequently in males than in females and in people who have risk factors for heart disease such as smokers. While the disease is commonly found in patients with atherosclerosis and coronary artery disease, it can occur by itself and in both cases it can cause health problems. The disease can cause the heart tissue to be deprived of blood and die due to decreased blood flow, and blockages due to blood clots or spasms of the blood vessel. This blood flow disruption can cause permanent damage to the muscle if the deprivation is prolonged. Coronary artery ectasia also increases the chance of developing large weak spots in the affected coronary arteries, or aneurysms that can rupture and result in death. The damage can result in angina which is pain in the chest and is a common complaint in these patients.
Popliteal artery
The deepest (most anterior) structure in the fossa, the popliteal artery runs in close proximity to the joint capsule of the knee as it spans the intercondylar fossa. Five genicular branches of the popliteal artery supply the capsule and ligaments of the knee joint. The genicular arteries are the superior lateral, superior medial, middle, inferior lateral, and inferior medial genicular arteries. They participate in the formation of the periarticular genicular anastomosis, a network of vessels surrounding the knee that provides collateral circulation capable of maintaining blood supply to the leg during full knee flexion, which may kink the popliteal artery.The branches of the popliteal artery are:
Vascular myelopathy
Vascular myelopathy (vascular disease of the spinal cord) refers to an abnormality of the spinal cord in regard to its blood supply. The blood supply is complicated and supplied by two major vessel groups: the posterior spinal arteries and the anterior spinal arteries—of which the Artery of Adamkiewicz is the largest. Both the posterior and anterior spinal arteries run the entire length of the spinal cord and receive anastomotic (conjoined) vessels in many places. The anterior spinal artery has a less efficient supply of blood and is therefore more susceptible to vascular disease. Whilst atherosclerosis of spinal arteries is rare, necrosis (death of tissue) in the anterior artery can be caused by disease in vessels originating from the segmental arteries such as atheroma (arterial wall swelling) or aortic dissection (a tear in the aorta).
Ultrasonography of chronic venous insufficiency of the legs
The great saphenous vein,(GSV) a superficial vein, is the longest vein in the body. It has its origin in the dorsal venous arch of the foot, a superficial vein which connects the small saphenous vein with the GSV. It travels up the leg and medial side of the thigh to reach the groin, where it drains into the common femoral vein. Along the length of the GSV, it receives numerous tributaries, (from the subcutaneous layer) and drains into the deep veins via the perforator veins. When seen in a scan, the GSV and the Giacomini vein, together with the accessory saphenous vein (ASV), form an image resembling an eye which is referred to as the "eye sign" or "eye image". . All veins which are between the skin and the superficial fascia are tributaries and all veins which cross the deep fascia to join the deep venous system are perforator veins.
Subclavian artery
In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.
Thyroid ima artery
The thyroid ima artery (thyroidea ima artery, arteria thyroidea ima, thyroid artery of Neubauer or the lowest thyroid artery) is an artery of the head and neck. It is an anatomical variant that, when present, supplies blood to the thyroid gland primarily, or the trachea, the parathyroid gland and the thymus gland (as thymica accessoria) in rare cases. It has also been reported to be a compensatory artery when one or both of the inferior thyroid arteries are absent and in a few cases the only source of blood to the thyroid gland. It varies in origin, size, blood supply, and termination, and occurs in only 3–10% of the population. Because of the variations and rarity, it may lead to surgical complications.
Hemodynamics
Pressure drops gradually as blood flows from the major arteries, through the arterioles, the capillaries until blood is pushed up back into the heart via the venules, the veins through the vena cava with the help of the muscles. At any given pressure drop, the flow rate is determined by the resistance to the blood flow. In the arteries, with the absence of diseases, there is very little or no resistance to blood. The vessel diameter is the most principal determinant to control resistance. Compared to other smaller vessels in the body, the artery has a much bigger diameter (4  mm), therefore the resistance is low.
Body cavity
The thoracic cavity consists of three cavities that fill the interior area of the chest.
The diaphragm divides the thoracic and the abdominal cavities. The abdominal cavity occupies the entire lower half of the trunk, anterior to the spine. Just under the abdominal cavity, anterior to the buttocks, is the pelvic cavity. The pelvic cavity is funnel shaped and is located inferior and anterior to the abdominal cavity. Together the abdominal and pelvic cavity can be referred to as the abdominopelvic cavity while the thoracic, abdominal, and pelvic cavities together can be referred to as the ventral body cavity.
Subdivisions of the Posterior (Dorsal) and Anterior (Ventral) Cavities
The anterior (ventral) cavity has two main subdivisions: the thoracic cavity and the abdominopelvic cavity. The thoracic cavity is the more superior subdivision of the anterior cavity, and it is enclosed by the rib cage. The thoracic cavity contains the lungs and the heart, which is located in the mediastinum. The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity. The abdominopelvic cavity is the largest cavity in the body. Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.
Pulmonary vein
The pulmonary veins are the veins that transfer oxygenated blood from the lungs to the heart. The largest pulmonary veins are the four "main pulmonary veins", two from each lung that drain into the left atrium of the heart. The pulmonary veins are part of the pulmonary circulation.
Abdominal aortic aneurysm
Abdominal aortic aneurysm (AAA or triple A) is a localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm or more than 50% larger than normal diameter. They usually cause no symptoms except when ruptured. Occasionally, abdominal, back, or leg pain may occur. Large aneurysms can sometimes be felt by pushing on the abdomen. Rupture may result in pain in the abdomen or back, low blood pressure, or loss of consciousness, and often results in death.
AAAs occur most commonly in those over 50 years old, in men, and among those with a family history. Additional risk factors include smoking, high blood pressure, and other heart or blood vessel diseases. Genetic conditions with an increased risk include Marfan syndrome and Ehlers-Danlos syndrome. AAAs are the most common form of aortic aneurysm. About 85% occur below the kidneys with the rest either at the level of or above the kidneys. In the United States, screening with abdominal ultrasound is recommended for males between 65 and 75 years of age with a history of smoking. In the United Kingdom and Sweden, screening all men over 65 is recommended. Once an aneurysm is found, further ultrasounds are typically done on a regular basis.
Not smoking is the single best way to prevent the disease. Other methods of prevention include treating high blood pressure, treating high blood cholesterol and not being overweight. Surgery is usually recommended when an AAA's diameter grows to >5.5 cm in males and >5.0 cm in females. Other reasons for repair include the presence of symptoms and a rapid increase in size (more than one centimeter per year). Repair may be either by open surgery or endovascular aneurysm repair (EVAR). As compared to open surgery, EVAR has a lower risk of death in the short term and a shorter hospital stay, but may not always be an option. There does not appear to be a difference in longer term outcomes between the two. With EVAR there is a higher need for repeat procedures.
AAAs affect between 2 and 8% of males over the age of 65. Rates among women are one-fourth as high. In those with an aneurysm less than 5.5 cm the risk of rupture in the next year is less than 1%. Among those with an aneurysm between 5.5 and 7 cm, the risk is about 10%, while for those with an aneurysm greater than 7 cm the risk is about 33%. Mortality if ruptured is 85% to 90%. During 2013, aortic aneurysms resulted in 168,200 deaths, up from 100,000 in 1990. In the United States AAAs resulted in between 10,000 and 18,000 deaths in 2009.
Adrenal gland
The adrenal glands have one of the greatest blood supply rates per gram of tissue of any organ: up to 60 small arteries may enter each gland. Three arteries usually supply each adrenal gland:
These blood vessels supply a network of small arteries within the capsule of the adrenal glands. Thin strands of the capsule enter the glands, carrying blood to them.
Circulatory system
The human arterial system originates from the aortic arches and from the dorsal aortae starting from week 4 of embryonic life. The first and second aortic arches regress and forms only the maxillary arteries and stapedial arteries respectively. The arterial system itself arises from aortic arches 3, 4 and 6 (aortic arch 5 completely regresses).
Coronary arteries
The coronary arteries are the arteries of the coronary circulation, which transports blood into and out of the cardiac muscle. They are mainly composed of the left and right coronary arteries, both of which give off branches. Coronary arteries can also be categorized as Epicardial (above the epicardium) and Microvascular (close to the endocardium).
Trabecular arteries
The lienal artery is remarkable for its large size in proportion to the size of the organ, and also for its tortuous course. It divides into six or more branches, which enter the hilum of the spleen and ramify throughout its substance, receiving sheaths from an involution of the external fibrous tissue.
Vagina
Blood is supplied to the vagina mainly via the vaginal artery, which emerges from a branch of the internal iliac artery or the uterine artery. The vaginal arteries anastamose (are joined) along the side of the vagina with the cervical branch of the uterine artery; this forms the azygos artery, which lies on the midline of the anterior and posterior vagina. Other arteries which supply the vagina include the middle rectal artery and the internal pudendal artery, all branches of the internal iliac artery. Three groups of lymphatic vessels accompany these arteries; the upper group accompanies the vaginal branches of the uterine artery; a middle group accompanies the vaginal arteries; and the lower group, draining lymph from the area outside the hymen, drain to the inguinal lymph nodes. Ninety-five percent of the lymphatic channels of the vagina are within 3 mm of the surface of the vagina.
Heart
Heart tissue receives blood from two arteries which arise just above the aortic valve. These are the left main coronary artery and the right coronary artery. The left main coronary artery splits shortly after leaving the aorta into two vessels, the left anterior descending and the left circumflex artery. The left anterior descending artery supplies heart tissue and the front, outer side, and the septum of the left ventricle. It does this by branching into smaller arteries—diagonal and septal branches. The left circumflex supplies the back and underneath of the left ventricle. The right coronary artery supplies the right atrium, right ventricle, and lower posterior sections of the left ventricle. The right coronary artery also supplies blood to the atrioventricular node (in about 90% of people) and the sinoatrial node (in about 60% of people). The right coronary artery runs in a groove at the back of the heart and the left anterior descending artery runs in a groove at the front. There is significant variation between people in the anatomy of the arteries that supply the heart The arteries divide at their furtherst reaches into smaller branches that join together at the edges of each arterial distribution.
Radial artery
In human anatomy, the radial artery is the main artery of the lateral aspect of the forearm.
Pancreas
The pancreas receives blood from branches of both the coeliac artery and superior mesenteric artery. The splenic artery runs along the top margin of the pancreas, and supplies the neck, body and tail of the pancreas through its pancreatic branches, the largest of which is called the greater pancreatic artery. The superior and inferior pancreaticoduodenal arteries run along the anterior and posterior surfaces of the head of the pancreas at its border with the duodenum. These supply the head of the pancreas.
Liver cytology
Cytology is the name given to the branch of biology that deals with the formation, structure and functionality of the cells. Liver cytology specializes in the study of liver cells. The main liver cells are called hepatocytes; however, there are other cells that can be observed in a liver sample such as Kupffer cells (macrophages). The liver is the biggest gland of the body. It has a wide variety of functions that range from the destruction of old blood cells to the control of the whole metabolism of macromolecules. In the fetus, the liver works as a principal center for hematopoiesis, function that is later replaced by the bone marrow. This hematopoietic function is not normally seen after birth; however, in certain pathological conditions this function may still be seen. It is important to note that the liver is an essential organ and it is the only one in the body that has the ability to regenerate itself after surgery or damage.
Biofluid dynamics
The Heart, arteries, and veins (a network of tubes to carry blood) constitute the cardiovascular system or circulatory system of our body which transports the blood throughout the body. The heart can be thought of as a muscular pump, consisting of four chambers, and pulsatile muscles which pump and circulates the blood through the vasculature. Arteries, arterioles, capillaries, venules, and veins make up the vasculature. The cardiovascular system circulates about 5 liters of blood at a rate of approximately 6 l/m. The pulmonary and the systemic circulations are the two parts of the vasculature. The pulmonary circulation system consists of the network of blood vessels from the right heart to the lungs and back to the left heart. The rest of the blood flow loop is called systemic circulation system. The pulmonary and systemic circulations take the blood through large arteries first and then branches into smaller arteries before reaching arterioles and capillaries. After capillaries, the blood enters the venules before joining smaller veins first and then larger veins before reaching the right heart. Thus completing the cycle of blood going to heart and then coming from it and going to all parts of the body.
The tricuspid valve, right heart (right ventricle), pulmonary valve, pulmonary artery, lungs, pulmonary veins and right heart are the elements of the Pulmonary Circulation System. The process of gas exchange, that is, exchange of carbon dioxide with oxygen in the lungs is the main function of the pulmonary system. The de-oxygenated blood from the right ventricle is pumped to the lungs where the capillaries surrounding the alveole sacks exchange carbon dioxide for oxygen. The red blood cells and the hemoglobin present in the blood, which is the main carrier of oxygen in the blood are responsible for this exchange of gases before they are carried to the left ventricle of the heart. The systemic circulation is responsible for taking the oxygenated blood to various organs and tissues via the arterial tree before taking the deoxygenated blood to the right ventricle using the venous system (a network of veins). Arteries carry the oxygenated blood while the veins carry the deoxygenated blood.
Coronary arteries
There is also the conus artery, which is only present in about 45 per cent of the human population, and which may provide collateral blood flow to the heart when the left anterior descending artery is occluded.
Takayasu's arteritis
Takayasu's arteritis (also known as Takayasu's disease, "aortic arch syndrome," "nonspecific aortoarteritis," and "pulseless disease") is a form of large vessel granulomatous vasculitis with massive intimal fibrosis and vascular narrowing, most commonly affecting often young or middle-age women of Asian descent, though anyone can be affected. It mainly affects the aorta (the main blood vessel leaving the heart) and its branches, as well as the pulmonary arteries. Females are about 8–9 times more likely to be affected than males.
Esophagus
Many blood vessels serve the esophagus, with blood supply varying along its course. The upper parts of the esophagus and the upper esophageal sphincter receive blood from the inferior thyroid artery, the parts of the esophagus in the thorax from the bronchial arteries and branches directly from the thoracic aorta, and the lower parts of the esophagus and the lower esophageal sphincter receive blood from the left gastric artery and the left inferior phrenic artery. The venous drainage also differs along the course of the esophagus. The upper and middle parts of the esophagus drain into the azygos and hemiazygos veins, and blood from the lower part drains into the left gastric vein. All these veins drain into the superior vena cava, with the exception of the left gastric vein, which is a branch of the portal vein. Lymphatically, the upper third of the esophagus drains into the deep cervical lymph nodes, the middle into the superior and posterior mediastinal lymph nodes, and the lower esophagus into the gastric and celiac lymph nodes. This is similar to the lymphatic drainage of the abdominal structures that arise from the foregut, which all drain into the celiac nodes.The upper esophagus lies at the back of the mediastinum behind the trachea, adjoining along the tracheoesophageal stripe, and in front of the erector spinae muscles and the vertebral column. The lower esophagus lies behind the heart and curves in front of the thoracic aorta. From the bifurcation of the trachea downwards, the esophagus passes behind the right pulmonary artery, left main bronchus, and left atrium. At this point it passes through the diaphragm.
Common carotid artery
In anatomy, the left and right common carotid arteries (carotids) () are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.
Celiac artery
The celiac artery is the only major artery that nourishes the abdominal digestive organs that does "not" have a similarly named vein.
Artery
Arteries have a blood pressure higher than other parts of the circulatory system. The pressure in arteries varies during the cardiac cycle. It is highest when the heart contracts and lowest when heart relaxes. The variation in pressure produces a pulse, which can be felt in different areas of the body, such as the radial pulse. Arterioles have the greatest collective influence on both local blood flow and on overall blood pressure. They are the primary "adjustable nozzles" in the blood system, across which the greatest pressure drop occurs. The combination of heart output (cardiac output) and systemic vascular resistance, which refers to the collective resistance of all of the body's arterioles, are the principal determinants of arterial blood pressure at any given moment.
Aorta
Another system divides the aorta with respect to its course and the direction of blood flow. In this system, the aorta starts as the ascending aorta then travels superiorly from the heart and then makes a hairpin turn known as the aortic arch. Following the aortic arch, the aorta then travels inferiorly as the descending aorta. The descending aorta has two parts. The aorta begins to descend in the thoracic cavity, and consequently is known as the thoracic aorta. After the aorta passes through the diaphragm, it is known as the abdominal aorta. The aorta ends by dividing into two major blood vessels, the common iliac arteries and a smaller midline vessel, the median sacral artery.
Traumatic aortic rupture
Traumatic aortic rupture, also called traumatic aortic disruption or transection, is a condition in which the aorta, the largest artery in the body, is torn or ruptured as a result of trauma to the body. The condition is frequently fatal due to the profuse bleeding that results from the rupture. Since the aorta branches directly from the heart to supply blood to the rest of the body, the pressure within it is very great, and blood may be pumped out of a tear in the blood vessel very rapidly. This can quickly result in shock and death. Thus traumatic aortic rupture is a common killer in automotive accidents and other traumas, with up to 18% of deaths that occur in automobile collisions being related to the injury. In fact, aortic disruption due to blunt chest trauma is the second leading cause of injury death behind traumatic brain injury.
American Liver Foundation
The liver may be the largest organ in the body, weighing in at 3½ pounds, but it is neither the most popular nor the best understood. So when a diagnosis of liver disease is made, it can be a frightening and confusing time in the lives of many patients and their families. That's where the American Liver Foundation comes in.
Aorta
The aortic arches start as five pairs of symmetrical arteries connecting the heart with the dorsal aorta, and then undergo a significant remodelling to form the final asymmetrical structure of the great arteries, with the 3rd pair of arteries contributing to the common carotids, the right 4th forming the base and middle part of the right subclavian artery and the left 4th being the central part of the aortic arch. The smooth muscle of the great arteries and the population of cells that form the aorticopulmonary septum that separates the aorta and pulmonary artery is derived from cardiac neural crest. This contribution of the neural crest to the great artery smooth muscle is unusual as most smooth muscle is derived from mesoderm. In fact the smooth muscle within the abdominal aorta is derived from mesoderm, and the coronary arteries, which arise just above the semilunar valves, possess smooth muscle of mesodermal origin. A failure of the aorticopulmonary septum to divide the great vessels results in persistent truncus arteriosus.
Celiac artery
The celiac artery is an essential source of blood, since the interconnections with the other major arteries of the gut are not sufficient to sustain adequate perfusion. Thus it cannot be safely ligated in a living person, and obstruction of the celiac artery will lead to necrosis of the structures it supplies.
Coronary circulation
Under the most common configuration of coronary arteries, there are three areas of anastomoses. Small branches of the LAD (left anterior descending/anterior interventricular) branch of the left coronary join with branches of the posterior interventricular branch of the right coronary in the interventricular sulcus(groove). More superiorly, there is an anastomosis between the circumflex artery (a branch of the left coronary artery) and the right coronary artery in the atrioventricular groove. There is also an anastomosis between the septal branches of the two coronary arteries in the interventricular septum. The photograph shows area of heart supplied by the right and the left coronary arteries.
Knee
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee is vulnerable to injury and to the development of osteoarthritis.
Bühler's anastomotic artery
In human anatomy, Bühler's anastamotic artery (also called the arc of Bühler) is an anastomotic shunt joining the superior mesenteric artery and the celiac trunk in vertical orientation. As the aforesaid arteries arise separately from different levels of the abdominal aorta, the shunt provides limited collateral circulation should a blockage occur in the intervening arterial segment. Bühler's artery is a rare phenomenon present in up to 3% of the population, and is thought to be an unobliterated remnant of the ventral longitudinal anastomosis present during embryological development.
Macrovascular disease
Macrovascular disease is a disease of any large ("macro") blood vessels in the body. It is a disease of the large blood vessels, including the coronary arteries, the aorta, and the sizable arteries in the brain and in the limbs.
Trigeminal artery
The trigeminal artery is an artery that supplies the basilar artery with blood during human embryonic development. Normally, the trigeminal artery involutes after the formation of the posterior communicating artery. However, in some cases, the artery persists into adulthood and can cause medical complications, including intracranial aneurysms.
Artery
The aorta is the root systemic artery (i.e., main artery). In humans, it receives blood directly from the left ventricle of the heart via the aortic valve. As the aorta branches, and these arteries branch in turn, they become successively smaller in diameter, down to the arterioles. The arterioles supply capillaries, which in turn empty into venules. The very first branches off of the aorta are the coronary arteries, which supply blood to the heart muscle itself. These are followed by the branches off the aortic arch, namely the brachiocephalic artery, the left common carotid, and the left subclavian arteries.
Motion (physics)
The human heart is constantly contracting to move blood throughout the body. Through larger veins and arteries in the body, blood has been found to travel at approximately 0.33 m/s. Though considerable variation exists, and peak flows in the venae cavae have been found between . additionally, the smooth muscles of hollow internal organs are moving. The most familiar would be the occurrence of peristalsis which is where digested food is forced throughout the digestive tract. Though different foods travel through the body at different rates, an average speed through the human small intestine is . The human lymphatic system is also constantly causing movements of excess fluids, lipids, and immune system related products around the body. The lymph fluid has been found to move through a lymph capillary of the skin at approximately 0.0000097 m/s.
Aorta
The aorta supplies all of the systemic circulation, which means that the entire body, except for the respiratory zone of the lung, receives its blood from the aorta. Broadly speaking, branches from the ascending aorta supply the heart; branches from the aortic arch supply the head, neck and arms; branches from the thoracic descending aorta supply the chest (excluding the heart and the respiratory zone of the lung); and branches from the abdominal aorta supply the abdomen. The pelvis and legs get their blood from the common iliac arteries.
Gastroduodenal artery
In anatomy, the gastroduodenal artery is a small blood vessel in the abdomen. It supplies blood directly to the pylorus (distal part of the stomach) and proximal part of the duodenum, and indirectly to the pancreatic head (via the anterior and posterior superior pancreaticoduodenal arteries).
Deep artery of arm
The deep artery of arm (also known as arteria profunda brachii and the deep brachial artery) is a large vessel which arises from the lateral and posterior part of the brachial artery, just below the lower border of the teres major.
Peripheral artery disease
Peripheral artery disease (PAD) is an abnormal narrowing of arteries other than those that supply the heart or brain. When narrowing occurs in the heart, it is called coronary artery disease, and in the brain, it is called cerebrovascular disease. Peripheral artery disease most commonly affects the legs, but other arteries may also be involved. The classic symptom is leg pain when walking which resolves with rest, known as intermittent claudication. Other symptoms include skin ulcers, bluish skin, cold skin, or abnormal nail and hair growth in the affected leg. Complications may include an infection or tissue death which may require amputation; coronary artery disease, or stroke. Up to 50% of people with PAD do not have symptoms.
The greatest risk factor for PAD is cigarette smoking. Other risk factors include diabetes, high blood pressure, kidney problems, and high blood cholesterol. The most common underlying mechanism of peripheral artery disease is atherosclerosis, especially in individuals over 40 years old. Other mechanisms include artery spasm, blood clots, trauma, fibromuscular dysplasia, and vasculitis. PAD is typically diagnosed by finding an ankle-brachial index (ABI) less than 0.90, which is the systolic blood pressure at the ankle divided by the systolic blood pressure of the arm. Duplex ultrasonography and angiography may also be used. Angiography is more accurate and allows for treatment at the same time; however, it is associated with greater risks.
It is unclear if screening for peripheral artery disease in people without symptoms is useful as it has not been properly studied. In those with intermittent claudication from PAD, stopping smoking and supervised exercise therapy improve outcomes. Medications, including statins, ACE inhibitors, and cilostazol may also help. Aspirin does not appear to help those with mild disease but is usually recommended in those with more significant disease due to the increased risk of heart attacks. Anticoagulants such as warfarin are not typically of benefit. Procedures used to treat the disease include bypass grafting, angioplasty, and atherectomy.
In 2015, about 155 million people had PAD worldwide. It becomes more common with age. In the developed world, it affects about 5.3% of 45- to 50-year-olds and 18.6% of 85- to 90-year-olds. In the developing world, it affects 4.6% of people between the ages of 45 and 50 and 15% of people between the ages of 85 and 90. PAD in the developed world is equally common among men and women, though in the developing world, women are more commonly affected. In 2015 PAD resulted in about 52,500 deaths, which is an increase from the 16,000 deaths in 1990.
Atrioventricular nodal branch
The atrioventricular nodal branch is a cardiac artery that is crucial because it feeds the atrioventricular node, necessary for the excitation and contraction of the ventricles. Most frequently (in over 80% of humans) it arises as a distal branch from the right coronary artery near the crux of the heart. In some people, the atrioventricular node instead receives blood from the circumflex branch of the left coronary artery, otherwise known as the left circumflex coronary artery or LCX. Very rarely, in approximately 2% of people, the vascular supply to the atrioventricular node arises from both the right coronary artery and the left circumflex branch.
Left gastroepiploic artery
The left gastroepiploic artery (or left gastro-omental artery), the largest branch of the splenic artery, runs from left to right about a finger’s breadth or more from the greater curvature of the stomach, between the layers of the greater omentum, and anastomoses with the right gastroepiploic (a branch of the right gastro-duodenal artery originating from the hepatic branch of the Coeliac trunk).
Liver
The liver is a reddish-brown, wedge-shaped organ with four lobes of unequal size and shape. A human liver normally weighs approximately , and has a width of about . It is both the heaviest internal organ and the largest gland in the human body.
Located in the right upper quadrant of the abdominal cavity, it rests just below the diaphragm, to the right of the stomach and overlies the gallbladder.
Adrenal artery
The adrenal arteries are arteries in the human abdomen that supply blood to the adrenal glands.
Intercostal arteries
The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery (supreme intercostal artery or superior intercostal artery) is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the costocervical trunk, which is a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein.
Mesenteric arteries
The term mesenteric artery is also used to describe smaller branches of these vessels which, particularly in smaller animals, provide a significant source of vascular resistance. These branches have a dense innervation by sympathetic nerves, allowing the brain to control their diameter and hence the resistance to blood flow to the gut. This is of particular importance when blood flow is required elsewhere, such as in exercise or shock, where a large proportion of the blood is required to supply the needs of skeletal muscle; by constricting the smaller mesenteric vessels, the resistance of blood flow to the gut increases, and hence blood flows more readily to other organs.
Aortic arch
The final section of the aortic arch is known as the "isthmus of aorta". This is so called because it is a narrowing (isthmus) of the aorta as a result of decreased blood flow when in foetal life. As the left ventricle of the heart increases in size throughout life, the narrowing eventually dilates to become a normal size. If this does not occur, this can result in coarctation of the aorta. The ductus arteriosus connects to the final section of the arch in foetal life and the ligamentum arteriosum when the ductus arteriosus regresses.
Superior mesenteric vessels
In human anatomy, the superior mesenteric artery arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas. The superior mesenteric artery lies to the left of the similarly named vein, the superior mesenteric vein.
Vein
The largest veins in the human body are the venae cavae. These are two large veins which enter the right atrium of the heart from above and below. The superior vena cava carries blood from the arms and head to the right atrium of the heart, while the inferior vena cava carries blood from the legs and abdomen to the heart. The inferior vena cava is retroperitoneal and runs to the right and roughly parallel to the abdominal aorta along the spine. Large veins feed into these two veins, and smaller veins into these. Together this forms the venous system.
Venae cavae
The inferior vena cava (or caudal vena cava in some animals) travels up alongside the abdominal aorta with blood from the lower part of the body. It is the largest vein in the human body.
E/A ratio
The heart is a biological pump designed to move blood through the brain and body. It has four chambers: two "upper" chambers called the atria, and two "lower" chambers called the ventricles. Anatomically, the atria are more posterior to the ventricles, but for ease of understanding, are often drawn "above" them. The atria are separated from the ventricles beneath by the atrioventricular valves, which open to allow blood into the ventricles and close when ventricular pressure exceeds atrial pressure.
Greater pancreatic artery
In human anatomy, the greater pancreatic artery (great pancreatic artery or arteria pancreatica magna), is the largest artery that supplies the pancreas. It arises from the splenic artery.
Descending aorta
The descending aorta is part of the aorta, the largest artery in the body. The descending aorta begins at the aortic arch that runs down through the chest and abdomen. The descending aorta anatomically consists of two portions or segments, the thoracic and the abdominal aorta, in correspondence with the two great cavities of the trunk in which it is situated. Within the abdomen, the descending aorta branches into the two common iliac arteries which serve the pelvis and eventually legs.
Artery
Systemic arteries are the arteries (including the peripheral arteries), of the systemic circulation, which is the part of the cardiovascular system that carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart. Systemic arteries can be subdivided into two types—muscular and elastic—according to the relative compositions of elastic and muscle tissue in their tunica media as well as their size and the makeup of the internal and external elastic lamina. The larger arteries (>10 mm diameter) are generally elastic and the smaller ones (0.1–10 mm) tend to be muscular. Systemic arteries deliver blood to the arterioles, and then to the capillaries, where nutrients and gases are exchanged.
Arm
The main artery in the arm is the brachial artery. This artery is a continuation of the axillary artery. The point at which the axillary becomes the brachial is distal to the lower border of teres major. The brachial artery gives off an unimportant branch, the deep artery of arm. This branching occurs just below the lower border of teres major.
Superior thoracic artery
The superior thoracic artery (highest thoracic artery) is a small artery located near the armpit in humans. It normally arises from the first division of the axillary artery, but may arise from the thoracoacromial artery, itself a branch of the second division of the axillary artery.
Coronary circulation
The left coronary artery distributes blood to the left side of the heart, the left atrium and ventricle, and the interventricular septum. The circumflex artery arises from the left coronary artery and follows the coronary sulcus to the left. Eventually, it will fuse with the small branches of the right coronary artery. The larger anterior interventricular artery, also known as the left anterior descending artery (LAD), is the second major branch arising from the left coronary artery. It follows the anterior interventricular sulcus around the pulmonary trunk. Along the way it gives rise to numerous smaller branches that interconnect with the branches of the posterior interventricular artery, forming anastomoses. An anastomosis is an area where vessels unite to form interconnections that normally allow blood to circulate to a region even if there may be partial blockage in another branch. The anastomoses in the heart are very small. Therefore, this ability is somewhat restricted in the heart so a coronary artery blockage often results in myocardial infarction causing death of the cells supplied by the particular vessel.
Carotid sinus
In human anatomy, the carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage. The carotid sinus extends from the bifurcation to the "true" internal carotid artery. The carotid sinus is sensitive to pressure changes in the arterial blood at this level. It is the major baroreception site in humans and most mammals.
Superior pancreaticoduodenal artery
At 42 letters, the posterior superior pancreaticoduodenal artery is also the artery with the longest name in the human body.
Genicular artery
Genicular artery (from Latin "geniculum", "knee") may refer to one of six arteries in the human leg, most of which anastomoses in the knee region.
Artery
Arteries form part of the circulatory system. They carry blood that is oxygenated after it has been pumped from the heart. Coronary arteries also aid the heart in pumping blood. Arteries carry oxygenated blood away from the heart to the tissues, except for pulmonary arteries, which carry blood to the lungs for oxygenation (usually veins carry deoxygenated blood to the heart but the pulmonary veins carry oxygenated blood as well). There are two types of unique arteries. The pulmonary artery carries blood from the heart to the lungs, where it receives oxygen. It is unique because the blood in it is not "oxygenated", as it has not yet passed through the lungs. The other unique artery is the umbilical artery, which carries deoxygenated blood from a fetus to its mother.
Elastic artery
An elastic artery (conducting artery or conduit artery) is an artery with a large number of collagen and elastin filaments in the tunica media, which gives it the ability to stretch in response to each pulse. This elasticity also gives rise to the Windkessel effect, which helps to maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow. Elastic arteries include the largest arteries in the body, those closest to the heart. They give rise to medium-sized vessels known as distributing arteries (or "muscular arteries").
Parathyroid artery
The parathyroid artery is the blood vessel that carries blood to each of the parathyroid glands. The parathyroid artery is the single individual artery that provides oxygenated blood supply to the parathyroid glands. While studies have concluded that most subjects' parathyoid glands are supplied by the thyroid arteries, up to 45% have been determined to have a "distinct anastomosing branch between the inferior and the superior thyroid arteries." Some have been shown to contain two are more parathroid arteries.
External carotid artery
The external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it splits into the external and internal carotid artery. It supplies blood to the face and neck.
Thyroid ima artery
The artery is only present in approximately 3–10% of the population. Thyroid ima artery is of surgical importance; due to its relatively small size and infrequent presence it can cause complications such as severe bleeding in surgery of the thorax, trachea, thyroid or parathyroid glands. Knowledge of occurrence of the artery is especially important during tracheostomy and thyroidectomy. Because the artery is smaller than the other thyroid vessels, and having an origin from one of the bigger vessels, a brisk cut while performing the surgery may cause complications such as severe hemorrhage and significant blood loss. The artery, if dissected, may draw back into the mediastinum and further complicate the condition by causing hemorrhage and clots in the thoracic cavity.
Head and neck anatomy
Blood circulates from the upper systemic loop originating at the aortic arch, and includes: the brachiocephalic artery, left common carotid artery and left subclavian artery. The head and neck are emptied of blood by the subclavian vein and jugular vein.
The brachiocephalic artery or trunk is the first and largest artery that branches to form the right common carotid artery and the right subclavian artery. This artery provides blood to the right upper chest, right arm, neck, and head, through a branch called right vertebral artery. The right and left vertebral artery feed into the basilar artery and upward to the Posterior cerebral artery, which provides most of the brain with oxygenated blood.
The posterior cerebral artery and the posterior communicating artery are within the circle of Willis.
Praxagoras
Praxagoras studied Aristotle's (384-322 BC) anatomy and improved it by distinguishing between artery and veins. He saw arteries as air tubes, similar to the trachea and bronchi, which carried pneuma, the mystic force of life. Arteries took the breath of life from the lungs to the left side of the heart through the aorta to the arteries of the body. He believed the arteries stemmed from the heart, but the veins came from the liver. Veins carried blood, which was created by digested food, to the rest of the body. The combination of blood and pneuma generated heat. As one of the humors, thick, cold phlegm gathered in the arteries would cause paralysis. Also, he believed that arteries were the channels through which voluntary motion was given to the body, and that the cause of epilepsy was the blocking of the aorta by this same accumulation of phlegm.
Umbilical artery
The umbilical arteries are one of two arteries in the human body, that carry deoxygenated blood, the other being the pulmonary arteries.
Superior epigastric artery
In human anatomy, superior epigastric artery refers to a blood vessel that carries oxygenated blood and arises from the internal thoracic artery (referred to as the internal mammary artery in the accompanying diagram). It anastomoses with the inferior epigastric artery at the umbilicus and supplies the anterior part of the abdominal wall and some of the diaphragm.
Cheek reconstruction
The external carotid artery (ECA), with contributions from the internal carotid artery (ICA) system, is the predominant arterial blood supply to the skin and muscles of the cheek. The greatest contribution is from the facial artery which traverses the face obliquely and terminates in the angular artery. The dorsal nasal artery runs along the nose and is the terminal branch of the ophthalmic artery, which is a terminal branch of the ICA. Many smaller branches and communications also exist.
Greater omentum
The right and left gastroepiploic arteries provide the sole blood supply to the greater omentum. Both are branches of the celiac trunk. The right gastroepiploic artery is a branch of the gastroduodenal artery, which is a branch of the common hepatic artery, which is a branch of the celiac trunk. The left gastroepiploic artery is the largest branch of the splenic artery, which is a branch of the celiac trunk. The right and left gastroepiploic arteries anastomose within the two layers of the anterior greater omentum along the greater curvature of the stomach.
Elastic artery
The pulmonary arteries, the aorta, and its branches together comprise the body's system of elastic arteries.
Blood vessel
The size of blood vessels is different for each of them. It ranges from a diameter of about 25 millimeters for the aorta to only 8 micrometers in the capillaries. This comes out to about a 3000-fold range.
Vasoconstriction is the constriction of blood vessels (narrowing, becoming smaller in cross-sectional area) by contracting the vascular smooth muscle in the vessel walls. It is regulated by vasoconstrictors (agents that cause vasoconstriction). These include paracrine factors (e.g. prostaglandins), a number of hormones (e.g. vasopressin and angiotensin) and neurotransmitters (e.g. epinephrine) from the nervous system.
Abdominal aorta
The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta (of the thorax).
Aortic rupture
Aortic rupture is the rupture or breakage of the aorta, the largest artery in the body. Aortic rupture is a rare, extremely dangerous condition. The most common cause is an abdominal aortic aneurysm that has ruptured spontaneously. Aortic rupture is distinct from aortic dissection, which is a tear through the inner wall of the aorta that can block the flow of blood through the aorta to the heart or abdominal organs.
Axillary artery
In human anatomy, the axillary artery is a large blood vessel that conveys oxygenated blood to the lateral aspect of the thorax, the axilla (armpit) and the upper limb. Its origin is at the lateral margin of the first rib, before which it is called the subclavian artery.
Femoral artery
The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. It enters the thigh from behind the inguinal ligament as the continuation of the external iliac artery. Injuries to the femoral artery can require reattachment surgery.
Dorsalis pedis artery
In human anatomy, the dorsalis pedis artery (dorsal artery of foot), is a blood vessel of the lower limb that carries oxygenated blood to the dorsal surface of the foot. It is located 1/3 from medial malleolus. It arises at the anterior aspect of the ankle joint and is a continuation of the anterior tibial artery. It terminates at the proximal part of the first intermetatarsal space, where it divides into two branches, the first dorsal metatarsal artery and the deep plantar artery. The dorsalis pedis communicates with the plantar blood supply of the foot through the deep plantar artery.
Median artery
The median artery is an artery that is occasionally found in humans and other animals.
It is present in 8% of individuals. When present, it is found in the forearm, between the radial artery and ulnar artery. It runs with the median nerve and supplies the same structures as that nerve. It may be unilateral or bilateral.
Lacrimal artery
The lacrimal artery is an artery that arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery. Not infrequently it is given off before the artery enters the orbit.
Small intestine
The small intestine receives a blood supply from the coeliac trunk and the superior mesenteric artery. These are both branches of the aorta. The duodenum receives blood from the coeliac trunk via the superior pancreaticoduodenal artery and from the superior mesenteric artery via the inferior pancreaticoduodenal artery. These two arteries both have anterior and posterior branches that meet in the midline and anastomose. The jejunum and ileum receive blood from the superior mesenteric artery. Branches of the superior mesenteric artery form a series of arches within the mesentery known as arterial arcades, which may be several layers deep. Straight blood vessels known as vasa recta travel from the arcades closest to the ileum and jejunum to the organs themselves.
Maxillary artery
The maxillary artery, the larger of the two terminal branches of the external carotid artery, arises behind the neck of the mandible, and is at first imbedded in the substance of the parotid gland; it passes forward between the ramus of the mandible and the sphenomandibular ligament, and then runs, either superficial or deep to the lateral pterygoid muscle, to the pterygopalatine fossa.
Aortic arches
The "first" and "second arches" disappear early. A remnant of the 1st arch forms part of the maxillary artery, a branch of the external carotid artery. The dorsal end of the second gives origin to the stapedial artery, a vessel which typically atrophies in humans but persists in some mammals. The stapedial artery passes through the ring of the stapes and divides into supraorbital, infraorbital, and mandibular branches which follow the three divisions of the trigeminal nerve. The infraorbital and mandibular branches arise from a common stem, the terminal part of which anastomoses with the external carotid artery. On the obliteration of the stapedial artery, this anastomosis enlarges and forms the internal maxillary artery; branches formerly of the stapedial artery are subsequently considered branches of the internal maxillary artery. The common stem of the infraorbital and mandibular branches passes between the two roots of the auriculotemporal nerve and becomes the middle meningeal artery; the original supraorbital branch of the stapedial is represented by the orbital twigs of the middle meningeal.
Giant cell
The most common form of giant cell formations is giant-cell arteritis, it is also known as temporal arteritis or cranial arteritis. This type of arteritis causes the arteries in the head, neck, and arm area to swell to abnormal sizes. Although this disease has no apparent causes it seems to be related to polymyalgia rheumatica.
Sciatic nerve
The sciatic nerve is the largest nerve in the human body.