How many mammary glands do human women have?
Female
A distinguishing characteristic of the class "Mammalia" is the presence of mammary glands. The mammary glands are modified sweat glands that produce milk, which is used to feed the young for some time after birth. Only mammals produce milk. Mammary glands are most obvious in humans, as the female human body stores large amounts of fatty tissue near the nipples, resulting in prominent breasts. Mammary glands are present in all mammals, although they are seldom used by the males of the species.
Bartholin's gland
The Bartholin's glands (also called Bartholin glands or greater vestibular glands) are two pea sized compound racemose glands located slightly posterior and to the left and right of the opening of the vagina. They secrete mucus to lubricate the vagina and are homologous to bulbourethral glands in males. However, while Bartholin's glands are located in the superficial perineal pouch in females, bulbourethral glands are located in the deep perineal pouch in males. Their duct length is 1.5 to 2.0 cm and open into navicular fossa. The ducts are paired and they open on the surface of the vulva.
Female reproductive system
The female reproductive system is made up of the internal and external sex organs that function in reproduction of new offspring. In the human the female reproductive system is immature at birth and develops to maturity at puberty to be able to produce gametes, and to carry a foetus to full term. The internal sex organs are the uterus, Fallopian tubes, and ovaries. The uterus or womb accommodates the embryo which develops into the foetus. The uterus also produces vaginal and uterine secretions which help the transit of sperm to the Fallopian tubes. The ovaries produce the ova (egg cells). The external sex organs are also known as the "genitals" and these are the organs of the vulva including the labia, clitoris, and vaginal opening. The vagina is connected to the uterus at the cervix.
Estrous cycle
Mammals share the same reproductive system, including the regulatory hypothalamic system that produces gonadotropin-releasing hormone in pulses, the pituitary gland that secretes follicle-stimulating hormone and luteinizing hormone, and the ovary itself that releases sex hormones including estrogens and progesterone.
Fatty acid metabolism
Adipose tissue and lactating mammary glands also take up glucose from the blood for conversion into triglycerides. This occurs in the same way as it does in the liver, except that these tissues do not release the triglycerides thus produced as VLDL into the blood. Adipose tissue cells store the triglycerides in their fat droplets, ultimately to release them again as free fatty acids and glycerol into the blood (as described above), when the plasma concentration of insulin is low, and that of glucagon and/or epinephrine is high. Mammary glands discharge the fat (as cream fat droplets) into the milk that they produce under the influence of the anterior pituitary hormone prolactin.
List of organs of the human body
This article contains a list of organs of the human body. It is widely believed that there are 79 organs; however, there is no universally standard definition of what constitution an organ, and some tissue groups' status as one is debated. Since there is no single standard definition of what an organ is, the number of organs varies depending on how one defines an organ. For example, this list contains much more than 79 different organs.Female reproductive system
Mammary ridge
The mammary ridge is primordial for the mammary gland on the breast in humans, and is associated with mammary gland and breast development.
Skin
Sweat glands and sebaceous glands are both unique to mammals, but other types of skin gland are found in other vertebrates. Fish typically have a numerous individual mucus-secreting skin cells that aid in insulation and protection, but may also have poison glands, photophores, or cells that produce a more watery, serous fluid. In amphibians, the mucus cells are gathered together to form sac-like glands. Most living amphibians also possess "granular glands" in the skin, that secrete irritating or toxic compounds.
Gastric mucosa
There are three types of glands: cardiac glands (in the proximal part of the stomach), fundic (oxyntic) glands (the dominating type of gland), and pyloric glands.
The cardiac glands mainly contain mucus-producing cells called foveolar cells.
The bottom part of the oxyntic glands is dominated by zymogenic (chief) cells that produce pepsinogen (an inactive precursor of the pepsin enzyme). Parietal cells, which secrete hydrochloric acid (HCl) are scattered in the glands, with most of them in the middle part. The upper part of the glands consist of mucous neck cells; in this part the dividing cells are seen. 
The pyloric glands contain mucus-secreting cells.
Mammal
Mammals ( from Latin "mamma" "breast") are vertebrate animals constituting the class Mammalia, and characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which they diverged in the late Triassic, 201–227 million years ago. There are around 5,450 species of mammals. The largest orders are the rodents, bats and Soricomorpha (shrews and others). The next three are the Primates (humans, apes, monkeys, and others), the Cetartiodactyla (whales and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others).
Intermammary cleft
In female human anatomy, the intermammary cleft or intermammary sulcus or sulcus intermammarius of a woman is delineated by where the fatty portions of each breast sits in relationship to the sternum (or breastbone). It divides the two mammary complexes that consist of two bodies of fatty pads, glandular tissues of mammary glands, connective tissues, and skin, as well as two duct systems (lactiferous duct of lymphatic vessel) and lobule alveoli emanating from two nipples. Lymph vessels can ventrally extend as far as the intermammary sulcus.
Iodine in biology
The human body contains about 15–20 mg of iodine, mostly concentrated in thyroid tissue (70–80%). Extra-thyroidal iodine exists in several other organs, including the mammary glands, eyes, gastric mucosa, cervix, ovary and salivary glands. In the cells of these tissues the iodide ion (I) enters directly by the sodium-iodide symporter (NIS). Different tissue responses for iodine and iodide occur in the mammary glands and the thyroid gland of rats. The role of iodine in mammary tissue is related to fetal and neonatal development, but its role in the other tissues is unknown. It has been shown to act as an antioxidant and antiproliferant in various tissues that can uptake iodine. Molecular iodine (I) has been shown to have a suppressive effect on benign and cancerous neoplasias.
Salivary gland pathology
There are 3 paired major salivary glands in humans (the parotid gland, the submandibular gland, and the sublingual gland), as well as about 800-1000 minor salivary glands in the oral mucosa of the mouth. The parotid gland is located in front of the ear, and it secretes its mostly serous saliva via the parotid duct (Stenson duct) into the mouth, usually opening roughly opposite the maxillary second molar. The submandibular gland is located medial to the angle of the mandible, and it drains its mixture of serous and mucous saliva via the submandibular duct (Wharton duct) into the mouth, usually opening in a punctum located in the floor of mouth. The sublingual gland is located below the tongue, in the floor of the mouth. It drains its mostly mucous saliva into the mouth via about 8-20 ducts which open along the plica sublingualis (a fold of tissue under the tongue).
Body shape
Females have enlarged breasts due to functional mammary glands, which develop from puberty onward due to the effects of estrogen. Mammary glands do not contain muscle tissue. The shape of female breasts is affected by age, genetic factors, and body weight.
Endocrine gland
The adrenal glands are located above the kidneys in humans and in front of the kidneys in other animals. The adrenal glands produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. It controls the behaviour during crisis and emotional situations. It stimulates the heart and its conducting tissues and metabolic processes.
Anovulation
This is the most common cause of anovulation and is thought to account for about 70% of all cases. About half the women with hormonal imbalances do not produce enough follicles to ensure the development of an ovule, possibly due to poor hormonal secretions from the pituitary gland or the hypothalamus. The pituitary gland controls most other hormonal glands in the human body. Therefore, any pituitary malfunctioning affects other glands under its influence, including the ovaries. This occurs in around 10% of cases. The mammary glands are also controlled by the pituitary gland, so lactation can also be affected. The pituitary gland is controlled by the hypothalamus. In 10% of cases, alterations in the chemical signals from the hypothalamus can easily seriously affect the ovaries.
Parathyroid gland
Parathyroid glands are found in all adult tetrapods; they vary in their number and position. Mammals typically have four parathyroid glands, while other types of animals typically have six. The removal of parathyroid glands in animals produces a condition resembling acute poisoning with irregular muscle contractions.
Endangered mammals of India
The mammals are the class of vertebrate animals characterized by the presence of mammary glands, which in females produce milk for the nourishment of young; the presence of hair or fur; specialized teeth; the presence of a neocortex region in the brain; and endothermic or "warm-blooded" bodies. The brain regulates endothermic and circulatory system, including a four-chambered heart. Mammals encompass some 5,500 species (including Humans), distributed in about 1,200 genera, 152 families and up to 46 orders, though this varies with the classification scheme.
Maternal physiological changes in pregnancy
The pituitary gland grows by about one-third as a result of hyperplasia of the lactrotrophs in response to the high plasma estrogen. Prolactin, which is produced by the lactrotrophs increases progressively throughout pregnancy. Prolactin mediates a change in the structure of the breast mammary glands from ductal to lobular-alveolar and stimulates milk production.
Skene's gland
The origin and production site of female ejaculation has not been proven. It has been postulated that the Skene's glands are the source of female ejaculation. Because the Skene's gland and male prostate act similarly in terms of prostate-specific antigen (PSA), which is an ejaculate protein identically produced in males, and in terms of prostate-specific acid phosphatase, this led to a trend of calling the Skene's glands the female prostate. Female ejaculate, which may emerge during sexual activity for some women, especially during female orgasm, contains biochemical markers of sexual function like human urinary protein 1 and the enzyme PDE5, whereas women without the gland had lower concentrations of these proteins. When examined with electron microscopy, both glands show similar secretory structures.
Mammary ridge
In human embryogenesis the mammary ridge usually appears as a narrow, microscopic ectodermal thickening during the first seven weeks of pregnancy and grows caudally as a narrow, linear ridge. In many mammals, these glands first appear as elevated ridges along the milk lines, which then separate into individual buds located in regions lateral to the ventral midline. The location of these buds varies according to species: they are located in the thoracic region in primates, in the inguinal area in ungulates, and along the entire length of the trunk in rodents and pigs.
Gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes (sex cells) and sex hormones of an organism. In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are the sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells.
Endocrine gland
Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. The hypothalamus and pituitary gland are neuroendocrine organs.
Mesenteric glands
Mesenteric glands, or mesenteric lymph nodes, are nodes located in the mesentery. They are of three classes: mesenteric lymph nodes, juxta-intestinal lymph nodes, and the superior middle group of mesenteric lymph nodes.
Excretory system
Like sweat glands, eccrine glands allow excess water to leave the body. The majority of eccrine glands are located mainly on the forehead, the bottoms of the feet, and the palms, although the glands are everywhere throughout the body. They help the body to maintain temperature control. Eccrine glands in the skin are unique to mammals.
Sweat gland
The number of active sweat glands varies greatly among different people, though comparisons between different areas (ex. axillae vs. groin) show the same directional changes (certain areas always have more active sweat glands while others always have fewer). According to Henry Gray's estimates, the palm has around 370 sweat glands per cm; the back of the hand has 200 per cm; the forehead has 175 per cm; the breast, abdomen, and forearm have 155 per cm; and the back and legs have 60–80 per cm.
Manatee
The manatee is unusual among mammals in having just six cervical vertebrae, a number that may be due to mutations in the homeotic genes. All other mammals have seven cervical vertebrae, other than the two-toed and three-toed sloths.
Ovary
Birds have only one functional ovary (the left), while the other remains vestigial. Ovaries in females are analogous to testes in males, in that they are both gonads and endocrine glands. Ovaries of some kind are found in the female reproductive system of many animals that employ sexual reproduction, including invertebrates. However, they develop in a very different way in most invertebrates than they do in vertebrates, and are not truly homologous.
Stomach
The gastric lining is usually divided into two regions, an anterior portion lined by fundic glands, and a posterior with pyloric glands. Cardiac glands are unique to mammals, and even then are absent in a number of species. The distributions of these glands vary between species, and do not always correspond with the same regions as in humans. Furthermore, in many non-human mammals, a portion of the stomach anterior to the cardiac glands is lined with epithelium essentially identical to that of the oesophagus. Ruminants, in particular, have a complex stomach, the first three chambers of which are all lined with oesophageal mucosa.
Mammary gland
Mammary gland development is characterized by the unique process by which the epithelium invades the stroma. The development of the mammary gland occurs mainly after birth. During puberty, tubule formation is coupled with branching morphogenesis which establishes the basic arboreal network of ducts emanating from the nipple.
Salivary gland
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual) as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous or seromucous (mixed).
Gastric glands
There are millions of gastric pits in the gastric mucosa and their necessary narrowness determines the tubular form of the gastric gland. More than one tube allows for the accommodation of more than one cell type. The form of each gastric gland is similar; they are all said to have a neck region that is closest to the pit entrance and basal regions on the lower parts of the tubes. The epithelium from the gastric mucosa travels into the pit and at the neck the epithelial cells change to short columnar granular cells. These cells almost fill the tube and the remaining lumen is continued as a very fine channel.
Mammary gland
Postnatally, the mammary ducts elongate into the mammary fat pad. Then, starting around four weeks of age, mammary ductal growth increases significantly with the ducts invading towards the lymph node. Terminal end buds, the highly proliferative structures found at the tips of the invading ducts, expand and increase greatly during this stage. This developmental period is characterized by the emergence of the terminal end buds and lasts until an age of about 7–8 weeks.
Breast
The breast is an apocrine gland that produces the milk used to feed an infant. The nipple of the breast is surrounded by the areola (nipple-areola complex). The areola has many sebaceous glands, and the skin color varies from pink to dark brown. The basic units of the breast are the terminal duct lobular units (TDLUs), which produce the fatty breast milk. They give the breast its offspring-feeding functions as a mammary gland. They are distributed throughout the body of the breast. Approximately two-thirds of the lactiferous tissue is within 30 mm of the base of the nipple. The terminal lactiferous ducts drain the milk from TDLUs into 4–18 lactiferous ducts, which drain to the nipple. The milk-glands-to-fat ratio is 2:1 in a lactating woman, and 1:1 in a non-lactating woman. In addition to the milk glands, the breast is also composed of connective tissues (collagen, elastin), white fat, and the suspensory Cooper's ligaments. Sensation in the breast is provided by the peripheral nervous system innervation by means of the front (anterior) and side (lateral) cutaneous branches of the fourth-, fifth-, and sixth intercostal nerves. The T-4 nerve (Thoracic spinal nerve 4), which innervates the dermatomic area, supplies sensation to the nipple-areola complex.
Strepsirrhini
Most primates have two mammary glands, but the number and positions vary between species within strepsirrhines. Lorises have two pairs, while others, like the ring-tailed lemur, have one pair on the chest (pectoral). The aye-aye also has two mammary glands, but they are located near the groin (inguinal). In females, the clitoris is sometimes enlarged and pendulous, resembling the male penis, which can make sex identification difficult for human observers. The clitoris may also have a bony structure in it, similar to the baculum (penis bone) in males. Most male primates have a baculum, but it is typically larger in strepsirrhines and usually forked at the tip.
Skin
Amphibians possess two types of glands, mucous and granular (serous). Both of these glands are part of the integument and thus considered cutaneous. Mucous and granular glands are both divided into three different sections which all connect to structure the gland as a whole. The three individual parts of the gland are the duct, the intercalary region, and lastly the alveolar gland (sac). Structurally, the duct is derived via keratinocytes and passes through to the surface of the epidermal or outer skin layer thus allowing external secretions of the body. The gland alveolus is a sac shaped structure which is found on the bottom or base region of the granular gland. The cells in this sac specialize in secretion. Between the alveolar gland and the duct is the intercalary system which can be summed up as a transitional region connecting the duct to the grand alveolar beneath the epidermal skin layer. In general, granular glands are larger in size than the mucous glands, however mucous glands hold a much greater majority in overall number.
Granular glands can be identified as venomous and often differ in the type of toxin as well as the concentrations of secretions across various orders and species within the amphibians. They are located in clusters differing in concentration depending on amphibian taxa. The toxins can be fatal to most vertebrates or have no effect against others. These glands are alveolar meaning they structurally have little sacs in which venom is produced and held before it is secreted upon defensive behaviors.
Reproductive biology
Human reproductive biology is primarily controlled through hormones, which send signals to the human reproductive structures to influence growth and maturation. These hormones are secreted by endocrine glands, and spread to different tissues in the human body. In humans, the pituitary gland synthesizes hormones used to control the activity of endocrine glands.
Salivary gland
There are 800 to 1,000 minor salivary glands located throughout the oral cavity within the submucosa of the oral mucosa in the tissue of the buccal, labial, and lingual mucosa, the soft palate, the lateral parts of the hard palate, and the floor of the mouth or between muscle fibers of the tongue. They are 1 to 2 mm in diameter and unlike the major glands, they are not encapsulated by connective tissue, only surrounded by it. The gland has usually a number of acini connected in a tiny lobule. A minor salivary gland may have a common excretory duct with another gland, or may have its own excretory duct. Their secretion is mainly mucous in nature and have many functions such as coating the oral cavity with saliva. Problems with dentures are sometimes associated with minor salivary glands if there is dry mouth present (see further discussion). The minor salivary glands are innervated by the seventh cranial or facial nerve.
Human digestive system
There are three pairs of main salivary glands and between 800 and 1,000 minor salivary glands, all of which mainly serve the digestive process, and also play an important role in the maintenance of dental health and general mouth lubrication, without which speech would be impossible. The main glands are all exocrine glands, secreting via ducts. All of these glands terminate in the mouth. The largest of these are the parotid glands—their secretion is mainly serous. The next pair are underneath the jaw, the submandibular glands, these produce both serous fluid and mucus. The serous fluid is produced by serous glands in these salivary glands which also produce lingual lipase. They produce about 70% of the oral cavity saliva. The third pair are the sublingual glands located underneath the tongue and their secretion is mainly mucous with a small percentage of saliva.
Mammary gland
There is preliminary evidence that soybean intake mildly stimulates the breast glands in pre- and postmenopausal women.
Bartholin's cyst
Two percent of women will have a Bartholin's gland cyst at some point in their lives. They occur at a rate of 0.55 per 1000 person-years and in women aged 35–50 years at a rate of 1.21 per 1000 person-years. The incidence of Bartholin duct cysts increases with age until menopause, and decreases thereafter. Hispanic women may be more often affected than white women and black women. The risk of developing a Bartholin's gland cyst increases with the number of childbirths.
Mammary gland
A mammary gland is a specific type of apocrine gland specialized for manufacture of colostrum when giving birth. Mammary glands can be identified as apocrine because they exhibit striking "decapitation" secretion. Many sources assert that mammary glands are modified sweat glands. Some authors dispute that and argue instead that they are sebaceous glands.
Human placentophagy
Maternal placentophagy is defined as "a mother’s ingestion of her own placenta postpartum, in any form, at any time". Of the more than 4000 species of placental mammals, most, including herbivores, regularly engage in maternal placentophagy, thought to be an instinct to hide any trace of childbirth from predators in the wild. The exceptions to placentophagy include mainly humans, Pinnipedia, Cetacea, and camels.
Mammal
The mammary glands of mammals are specialized to produce milk, the primary source of nutrition for newborns. The monotremes branched early from other mammals and do not have the nipples seen in most mammals, but they do have mammary glands. The young lick the milk from a mammary patch on the mother's belly.
Mother
Biological motherhood for humans, as in other mammals, occurs when a pregnant female gestates a fertilized ovum (the "egg"). A female can become pregnant through sexual intercourse after she has begun to ovulate. In well-nourished girls, menarche (the first menstrual period) usually takes place around the age of 12 or 13.
Endocrine system
The endocrine system is a chemical messenger system consisting of hormones, the group of glands of an organism that secrete those hormones directly into the circulatory system to regulate the function of distant target organs, and the feedback loops which modulate hormone release so that homeostasis is maintained. In humans, the major endocrine glands are the thyroid gland and the adrenal glands. In vertebrates, the hypothalamus is the neural control center for all endocrine systems. The study of the endocrine system and its disorders is known as endocrinology. Endocrinology is a branch of internal medicine.
Salivary gland
About 20,000 protein coding genes are expressed in human cells and 60% of these genes are expressed in normal, adult salivary glands. Less than 100 genes are more specifically expressed in the salivary gland. The salivary gland specific genes are mainly genes that encode for secreted proteins and compared to other organs in the human body; the salivary gland has the highest fraction of secreted genes. The heterogeneous family of proline-rich, human salivary glycoproteins, such as PRB1 and PRH1, are salivary gland specific proteins with highest level of expression. Examples of other specifically expressed proteins include the digestive amylase enzyme AMY1A, the mucin MUC7 and statherin, all of major importance for specific characteristics of saliva.
Male reproductive system
Three accessory glands provide fluids that lubricate the duct system and nourish the sperm cells. They are the seminal vesicles, the prostate gland, and the bulbourethral glands (Cowper glands).
The embryonic and prenatal development of the male reproductive system is the process whereby the reproductive organs grow, mature and are established. It begins with a single fertilized egg and culminates 38 weeks later with birth of a male child. It is a part of the stages of sexual differentiation. The development of the male reproductive system coincides with the urinary system. The development of them can also be described together as the development of the urinary and reproductive organs.
Maternal behavior in vertebrates
Mammals are a class of vertebrates that contain mammary glands which secrete milk that nourishes their offspring. This maternal behavior is unique from all other vertebrate classes. The basic maternal care patterns in mammals involve the internal incubation during gestation, the delivery of young, and maternal care until the young are weaned. The way a female mammal cares for their young depends on the level of maturation of the offspring at birth. There are three main categories of newborn maturation that different species of mammals exhibit. Altricial young (marsupials, rodents) are completely helpless and dependent on their mothers, precocial young (elephants, cattle) have highly developed sensory and motor functions at birth, and primates who are semi-helpless young, have an intermediate level of maturation. This variation in maturation at birth requires different maternal care from the mother.
Breast
In women, the breasts overlie the pectoralis major muscles and usually extend from the level of the second rib to the level of the sixth rib in the front of the human rib cage; thus, the breasts cover much of the chest area and the chest walls. At the front of the chest, the breast tissue can extend from the clavicle (collarbone) to the middle of the sternum (breastbone). At the sides of the chest, the breast tissue can extend into the axilla (armpit), and can reach as far to the back as the latissimus dorsi muscle, extending from the lower back to the humerus bone (the longest bone of the upper arm). As a mammary gland, the breast is composed of differing layers of tissue, predominantly two types: adipose tissue; and glandular tissue, which affects the lactation functions of the breasts.
Morphologically the breast is tear-shaped. The superficial tissue layer (superficial fascia) is separated from the skin by 0.5–2.5 cm of subcutaneous fat (adipose tissue). The suspensory Cooper's ligaments are fibrous-tissue prolongations that radiate from the superficial fascia to the skin envelope. The female adult breast contains 14–18 irregular lactiferous lobes that converge at the nipple. The 2.0–4.5 mm milk ducts are immediately surrounded with dense connective tissue that support the glands. Milk exits the breast through the nipple, which is surrounded by a pigmented area of skin called the areola. The size of the areola can vary widely among women. The areola contains modified sweat glands known as Montgomery's glands. These glands secrete oily fluid that lubricate and protect the nipple during breastfeeding. Volatile compounds in these secretions may also serve as an olfactory stimulus for the newborn's appetite.
Mammary gland
During embryonic development, IGF-1 levels are low, and gradually increase from birth to puberty. At puberty, the levels of GH and IGF-1 reach their highest levels in life and estrogen begins to be secreted in high amounts in females, which is when ductal development mostly takes place. Under the influence of estrogen, stromal and fat tissue surrounding the ductal system in the mammary glands also grows. After puberty, GH and IGF-1 levels progressively decrease, which limits further development until pregnancy, if it occurs. During pregnancy, progesterone and prolactin are essential for mediating lobuloalveolar development in estrogen-primed mammary gland tissue, which occurs in preparation of lactation and nursing.
Preorbital gland
Deer have seven major external scent glands, distributed throughout their bodies. These glands are the forehead glands (located on the forehead), the preorbital glands (located below the eyes), the nasal glands (located inside the nostrils), the interdigital glands (located between the toes), the preputial gland (located inside the foreskin of the deer's penis), the metatarsal glands (located outside of the hind legs), and the tarsal glands (located inside of the hind legs). Though it is not their primary function, the salivary glands also function as scent glands. Deer rely heavily on these scent glands to communicate with other members of their species, and possibly even with members of other species. A deer may rub its preorbital gland (e.g., on a branch) purely for pleasure.
Areolar gland
The number of glands can vary greatly, usually averaging from four to 28 per breast.
Female ejaculation
However, women's writing of that time portrayed this in more positive terms. Thus we find Almeda Sperry writing to Emma Goldman in 1918, about the "rhythmic spurt of your love juices". Anatomical knowledge was also advanced by Alexander Skene's description of para-urethral or periurethral glands (glands around the urethra) in 1880, which have been variously claimed to be one source of the fluids in the ejaculate, and now commonly referred to as the Skene's glands.
Cervical ganglia
The cervical ganglia are paravertebral ganglia of the sympathetic nervous system. Preganglionic nerves from the thoracic spinal cord enter into the cervical ganglions and synapse with its postganglionic fibers or nerves. The cervical ganglion has three paravertebral ganglia: Nerves emerging from cervical sympathetic ganglia contribute to the cardiac plexus, among other things.
Unlike all other ganglia, the medial branches of the cervical ganglia are 95% postganglionic axons.
Sebaceous gland
Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals. In humans, they occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. The type of secretion of the sebaceous glands is referred to as holocrine. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Fordyce spots are ectopic (misplaced) sebaceous glands found usually on the lips, gums and inner cheeks, and genitals. Areolar glands surround the female nipples.
Mammalian reproduction
The mammalian female reproductive system likewise contains two main divisions: the vagina and uterus, which act as the receptacle for the sperm, and the ovaries, which produce the female's ova. All of these parts are always internal. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, the ovaries release an ovum, which passes through the fallopian tube into the uterus.
Involution (medicine)
During pregnancy until after birth, mammary glands grow steadily to a size required for optimal milk production. At the end of breastfeeding, the number of cells in the mammary gland becomes reduced until approximately the same number is reached as before the start of pregnancy.
Male accessory gland
The products of these glands serve to nourish and activate the spermatozoa, to clear the urethral tract prior to ejaculation, serve as the vehicle of transport of the spermatozoa in the female tract, and to plug the female tract after placement of spermatozoa to help ensure fertilization. Although the glands are usually described as being branched tubular or branched tubuloalveolar, they vary in their organization and in their distribution in different species.
Mammary gland
Lactation is thought to have developed long before the evolution of the mammary gland and mammals; see evolution of lactation.
Gonadotropin
Gonadotropins are glycoprotein polypeptide hormones secreted by gonadotrope cells of the anterior pituitary of vertebrates. This family includes the mammalian hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), and placental/chorionic gonadotropins, human chorionic gonadotropin (hCG) and equine chorionic gonadotropin (eCG), as well as at least two forms of fish gonadotropins. These hormones are central to the complex endocrine system that regulates normal growth, sexual development, and reproductive function. LH and FSH are secreted by the anterior pituitary gland, while hCG and eCG are secreted by the placenta in pregnant humans and mares, respectively. The gonadotropins act on the gonads, controlling gamete and sex hormone production.
Nipple
In mammals, a nipple (also called mammary papilla or teat) is a small projection of skin containing the outlets for 15–20 lactiferous ducts arranged cylindrically around the tip. Marsupials and eutherian mammals typically have an even number of nipples arranged bilaterally, from as few as two to as many as 19.
Endocrine gland
The ovaries of the female, located in the pelvic cavity, release two main hormones. Secretion of estrogens by the ovarian follicles begins at puberty under the influence of FSH. Estrogens stimulate maturation of the female reproductive system and development of the secondary sexual characteristics. Progesterone is released in response to high blood levels of LH. It works with estrogens in establishing the menstrual cycle.
Reproductive system
The human female reproductive system is a series of organs primarily located inside of the body and around the pelvic region of a female that contribute towards the reproductive process. The human female reproductive system contains three main parts: the vulva, which leads to the vagina, the vaginal opening, to the uterus; the uterus, which holds the developing fetus; and the ovaries, which produce the female's ova. The breasts are involved during the parenting stage of reproduction, but in most classifications they are not considered to be part of the female reproductive system.
Male accessory gland
Male accessory glands (MAG) in humans are the seminal vesicles, prostate gland, and the bulbourethral glands (also called Cowper's glands).
In insects, male accessory glands produce products that mix with the sperm to protect and preserve them, including seminal fluid proteins. Some insecticides can induce an increase in the protein content of the male accessory glands of certain types of insects. This has the unintended effect of increasing the number of offspring they produce.
Gastric glands
The fundic glands (or "oxyntic glands"), are found in the fundus and body of the stomach. They are simple almost straight tubes, two or more of which open into a single duct. "Oxyntic" means acid-secreting and they secrete hydrochloric acid (HCl) and intrinsic factor.
List of glands of the human body
This page contains a list of glands of the human body
There are several specialized glands within the human integumentary system that are derived from apocrine or sebaceous gland precursors. There are no specialized variants of eccrine glands.
Mammary ridge
The mammary ridge or mammary crest, is a primordium specific for the development of the mammary gland.
Preputial gland
There is debate about whether humans have functional homologues to preputial glands. Preputial glands were first noted by Edward Tyson and in 1694 fully described by William Cowper who named them Tyson's glands after Tyson. They are described as modified sebaceous glands located around the corona and inner surface of the prepuce of the human penis. They are believed to be most frequently found in the balanopreputial sulcus. Their secretion may be one of the components of smegma.
Sweat gland
Specialized sweat glands, including the ceruminous glands, mammary glands, ciliary glands of the eyelids, and sweat glands of the nasal vestibulum, are modified apocrine glands. Ceruminous glands are near the ear canals, and produce cerumen (earwax) that mixes with the oil secreted from sebaceous glands. Mammary glands use apocrine secretion to produce milk.
Areola
The mature human female nipple has several small openings arranged radially around the tip of the nipple (lactiferous ducts) from which milk is released during lactation. Other small openings in the areola are sebaceous glands, known as Montgomery's glands.
Gastric glands
The three types of gland are all located beneath the gastric pits within the gastric mucosa–the mucous membrane of the stomach. The gastric mucosa is pitted with innumerable gastric pits which each house 3-5 gastric glands.
Endocrine system
Special features of endocrine glands are, in general, their ductless nature, their vascularity, and commonly the presence of intracellular vacuoles or granules that store their hormones. In contrast, exocrine glands, such as salivary glands, sweat glands, and glands within the gastrointestinal tract, tend to be much less vascular and have ducts or a hollow lumen. A number of glands that signal each other in sequence are usually referred to as an axis, for example, the hypothalamic-pituitary-adrenal axis.
Mammary gland
The basic components of a mature mammary gland are the "alveoli" (hollow cavities, a few millimeters large) lined with milk-secreting cuboidal cells and surrounded by myoepithelial cells. These alveoli join to form groups known as "lobules". Each lobule has a "lactiferous duct" that drains into openings in the nipple. The myoepithelial cells contract under the stimulation of oxytocin, excreting the milk secreted by alveolar units into the lobule lumen toward the nipple. As the infant begins to suck, the oxytocin-mediated "let down reflex" ensues and the mother's milk is secreted — not sucked from the gland — into the baby's mouth.
Ptosis (breasts)
Mammary glands remain relatively constant throughout life. Fat tissue surrounds the mammary glands, and its volume will normally vary throughout life. Although the exact mechanisms that determine breast shape and size are largely unknown, the amount and distribution of fat tissue and, to a lesser extent, mammary tissue, cause variations in breast size, shape and volume. The Cooper's ligaments offer minimal connective tissue to support the breasts.
Mammary analogue secretory carcinoma
Mammary analogue secretory carcinoma (MASC) (also termed MASC; the "SG" subscript indicates salivary gland)) is a salivary gland neoplasm that shares a genetic mutation with certain types of breast cancer. MASC was first described by Skálová et al. in 2010. The authors of this report found a chromosome translocation in certain salivary gland tumors that was identical to the (12;15)(p13;q25) fusion gene mutation found previously in secretory carcinoma, a subtype of invasive ductal carcinoma of the breast.
Parathyroid gland
In the early development of the human embryo, a series of five pharyngeal arches and four pharyngeal pouches form that give rise to the face, neck, and surrounding structures. The pouches are numbered such that the first pouch is the closest to the top of the embryo's head and the fourth is the furthest from it. The parathyroid glands originate from the interaction of the endoderm of the third and fourth pouch and neural crest mesenchyme. The position of the glands reverses during embryological life. The pair of glands which is ultimately inferior develops from the third pouch with the thymus, whereas the pair of glands which is ultimately superior develops from the fourth pouch. During embryological development, the thymus migrates downwards, dragging the inferior glands with it. The superior pair are not dragged downwards by the fourth pouch to the same degree. The glands are named after their final, not embryological, positions. Since the thymus's ultimate destination is in the mediastinum of the chest, it is occasionally possible to have ectopic parathyroids derived from the third pouch within the chest cavity if they fail to detach in the neck.
Ovary
At maturity, ovaries secrete estrogen, testosterone, inhibin, and progesterone. In women, fifty percent of testosterone is produced by the ovaries and adrenal glands and released directly into the blood stream. Estrogen is responsible for the appearance of secondary sex characteristics for females at puberty and for the maturation and maintenance of the reproductive organs in their mature functional state. Progesterone prepares the uterus for pregnancy, and the mammary glands for lactation. Progesterone functions with estrogen by promoting menstrual cycle changes in the endometrium.
Human sexuality
The female internal reproductive organs are the vagina, uterus, Fallopian tubes, and ovaries. The vagina is a sheath-like canal that extends from the vulva to the cervix. It receives the penis during intercourse and serves as a depository for sperm. The vagina is also the birth canal; it can expand to during labor and delivery. The vagina is located between the bladder and the rectum. The vagina is normally collapsed, but during sexual arousal it opens, lengthens, and produces lubrication to allow the insertion of the penis. The vagina has three layered walls; it is a self-cleaning organ with natural bacteria that suppress the production of yeast. The G-spot, named after the Ernst Gräfenberg who first reported it in 1950, may be located in the front wall of the vagina and may cause orgasms. This area may vary in size and location between women; in some it may be absent. Various researchers dispute its structure or existence, or regard it as an extension of the clitoris.
Lactation
Charles Darwin recognized that mammary glands seemed to have developed specifically from cutaneous glands, and hypothesized that they evolved from glands in brood pouches of fish, where they would provide nourishment for eggs. The latter aspect of his hypothesis has not been confirmed; however, more recently the same mechanism has been postulated for early synapsids.
Adult stem cell
Mammary stem cells provide the source of cells for growth of the mammary gland during puberty and gestation and play an important role in carcinogenesis of the breast. Mammary stem cells have been isolated from human and mouse tissue as well as from cell lines derived from the mammary gland. Single such cells can give rise to both the luminal and myoepithelial cell types of the gland, and have been shown to have the ability to regenerate the entire organ in mice.
Gastric pits
Gastric pits are indentations in the stomach which denote entrances to 3-5 tubular shaped gastric glands. They are deeper in the pylorus than they are in the other parts of the stomach. The human stomach has several million of these pits which dot the surface of the lining epithelium. Surface mucous cells line the pits themselves but give way to a series of other types of cells which then line the glands themselves.
Head and neck anatomy
The pituitary gland secretes hormones that directly impact the body as well as hormones that indirectly control body functions because they activate other endocrine glands, such as the adrenal cortex (ACTH) and the thyroid gland (TSH). These two glands when stimulated by pituitary hormones then release their own hormones.
The pituitary gland has two lobes, the anterior lobe and the posterior lobe. The anterior lobe secretes: growth hormone (GH), Luteinizing hormone (LH), Follicle stimulating hormone (FSH), Adrenocorticotropic hormone (ACTH), Thyroid-stimulating hormone (TSH), Prolactin (PRL), and the posterior lobe secretes: Antidieuretic hormone (ADH), and Oxytocin. There is an intermediate lobe, in adult humans it is just a thin layer of cells between the anterior and posterior pituitary, nearly indistinguishable from the anterior lobe. The intermediate lobe produces melanocyte-stimulating hormone (MSH).
C19MC miRNA cluster
The C19MC miRNA cluster is a microRNA cluster consisting of 46 genes. These 46 genes encode 59 mature miRNAs. The C19MC miRNA cluster is only found in primate (including human) genomes and expresses miRNAs almost exclusively in the placenta, but also in testis, embryonic stem cells, and some tumors. They are also expressed highly in trophoblast-derived vesicles, including exosomes. C19MC miRNAs have been shown to be among the most expressed miRNAs in the human placenta and are also found in the serum of pregnant women.
Sebaceous gland
The preputial glands of mice and rats are large modified sebaceous glands that produce pheromones used for territorial marking. These and the scent glands in the flanks of hamsters have a similar composition to human sebaceous glands, are androgen responsive, and have been used as a basis for study. Some species of bat, including the Mexican free-tailed, have a specialized sebaceous gland occurring on the throat called a "gular gland". This gland is present more frequently in males than females, and it is hypothesized that the secretions of the gland are used for scent-marking.
Mammary gland
The breasts of the adult human female vary from most other mammals that tend to have less conspicuous mammary glands. The number and positioning of mammary glands varies widely in different mammals. The protruding teats and accompanying glands can be located anywhere along the two milk lines. In general most mammals develop mammary glands in pairs along these lines, with a number approximating the number of young typically birthed at a time. The number of teats varies from 2 (in most primates) to 18 (in pigs). The Virginia opossum has 13, one of the few mammals with an odd number. The following table lists the number and position of teats and glands found in a range of mammals:
Reproductive system
In mammals, the major organs of the reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs, including the gamete-producing gonads (testicles and ovaries). Diseases of the human reproductive system are very common and widespread, particularly communicable sexually transmitted diseases.
Implantation (human embryo)
Furthermore, the surface of the endometrium produces a kind of rounded cells, which cover the whole area toward the uterine cavity. This happens about 9 to 10 days after ovulation. These cells are called decidual cells, which emphasises that the whole layer of them is shed off in every menstruation if no pregnancy occurs, just as leaves of deciduous trees. The uterine glands, on the other hand, decrease in activity and degenerate around 8 to 9 days after ovulation in absence of pregnancy.
Gland
A gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland).
Sweat gland
Non-primate mammals have eccrine sweat glands only on the palms and soles. Apocrine glands cover the rest of the body, though they are not as effective as humans' in temperature regulation (with the exception of horses'). Prosimians have a 1:20 ratio of follicles with apocrine glands versus follicles without. They have eccrine glands between hairs over most of their body (while humans have them between the hairs on their scalp).
Mammary alveolus
A mammary alveolus (plural: alveoli, from Latin "alveolus", "little cavity") is a small cavity or sac found in the mammary gland. Mammary alveoli are the site of milk production and storage in the mammary gland. Mammary alveoli cluster into groups called lobules, and each breast may contain 15–20 of these lobules. The lobules drain milk through the lactiferous ducts out of the nipples.
Human sexuality
The ovaries are the female gonads; they develop from the same embryonic tissue as the testicles. The ovaries are suspended by ligaments and are the source where ova are stored and developed before ovulation. The ovaries also produce female hormones progesterone and estrogen. Within the ovaries, each ovum is surrounded by other cells and contained within a capsule called a primary follicle. At puberty, one or more of these follicles are stimulated to mature on a monthly basis. Once matured, these are called Graafian follicles. The female reproductive system does not produce the ova; about 60,000 ova are present at birth, only 400 of which will mature during the woman's lifetime.
Body odor
In humans, the formation of body odors is caused by factors such as diet, gender, health, and medication, but the major contribution comes from bacterial activity on skin gland secretions. Humans have three types of sweat glands; eccrine sweat glands, apocrine sweat glands and sebaceous glands. Eccrine sweat glands are present from birth, while the two latter become activated during puberty. Among the different types of human skin glands, the body odor is primarily the result of the apocrine sweat glands, which secrete the majority of chemical compounds needed for the skin flora to metabolize it into odorant substances. This happens mostly in the axillary (armpit) region, although the gland can also be found in the areola, anogenital region, and around the navel. In humans, the armpit regions seem more important than the genital region for body odor which may be related to human bipedalism. The genital and armpit regions also contain springy hairs which help diffuse body odors.
Endometrium
About 20,000 protein coding genes are expressed in human cells and some 70% of these genes are expressed in the normal endometrium. Just over 100 of these genes are more specifically expressed in the endometrium with only a handful genes being highly endometrium specific. The corresponding specific proteins are expressed in the glandular and stromal cells of the endometrial mucosa. The expression of many of these proteins vary depending on the menstrual cycle, for example the progesterone receptor and thyrotropin-releasing hormone both expressed in the proliferative phase, and PAEP expressed in the secretory phase. Other proteins such as the HOX11 protein that is required for female fertility, is expressed in endometrial stroma cells throughout the menstrual cycle. Certain specific proteins such as the estrogen receptor are also expressed in other types of female tissue types, such as the cervix, fallopian tubes, ovaries and breast.
Gastric glands
The cardiac glands are found in the cardia of the stomach which is the part nearest to the heart, enclosing the opening where the esophagus joins to the stomach. Only cardiac glands are found here and they primarily secrete mucus. They are fewer in number than the other gastric glands and are more shallowly positioned in the mucosa. There are two kinds - either simple tubular with short ducts or compound racemose resembling the duodenal Brunner's glands
Stomach
The stomach also possesses a serosa, consisting of layers of connective tissue continuous with the peritoneum.
In humans, different types of cells are found at the different layers of the gastric glands.
The three types of gland are all located beneath the gastric pits within the gastric mucosa–the mucous membrane of the stomach. The gastric mucosa is pitted with innumerable gastric pits which house the gastric glands.
Eastern mole
The sexes are determined externally by the number of openings in the groin area: the female has three – the forward one is the urinary opening (in the urinary papilla or projection), the second is the vagina, and the third is the anus at the tail. The male has two openings – the combined urinary/reproductive opening in the penis, and the anus. The testes never descend into a scrotum but remain within the body cavity. There are six teats on the belly – a pair at the chest, a pair at the groin, and a pair between the two. A rank, musky odor is emitted from a scent gland on the belly, and is left on the floor of the tunnel as the mole passes. It probably serves as a form of communication between the sexes during the breeding season, and to discourage predators. Other scent glands are found at the anus.
Mammary gland
Estrogen and growth hormone (GH) are essential for the ductal component of mammary gland development, and act synergistically to mediate it. Neither estrogen nor GH are capable of inducing ductal development without the other. The role of GH in ductal development has been found to be mostly mediated by its induction of the secretion of insulin-like growth factor 1 (IGF-1), which occurs both systemically (mainly originating from the liver) and locally in the mammary fat pad through activation of the growth hormone receptor (GHR). However, GH itself also acts independently of IGF-1 to stimulate ductal development by upregulating estrogen receptor (ER) expression in mammary gland tissue, which is a downstream effect of mammary gland GHR activation. In any case, unlike IGF-1, GH itself is not essential for mammary gland development, and IGF-1 in conjunction with estrogen can induce normal mammary gland development without the presence of GH. In addition to IGF-1, other paracrine growth factors such as epidermal growth factor (EGF), transforming growth factor beta (TGF-β), amphiregulin, fibroblast growth factor (FGF), and hepatocyte growth factor (HGF) are involved in breast development as mediators downstream to sex hormones and GH/IGF-1.
Mammary gland
Lactiferous duct development occurs in females in response to circulating hormones. First development is frequently seen during pre- and postnatal stages, and later during puberty. Estrogen promotes branching differentiation, whereas in males testosterone inhibits it. A mature duct tree reaching the limit of the fat pad of the mammary gland comes into being by bifurcation of duct terminal end buds (TEB), secondary branches sprouting from primary ducts and proper duct lumen formation. These processes are tightly modulated by components of mammary epithelial ECM interacting with systemic hormones and local secreting factors. However, for each mechanism the epithelial cells' "niche" can be delicately unique with different membrane receptor profiles and basement membrane thickness from specific branching area to area, so as to regulate cell growth or differentiation sub-locally. Important players include beta-1 integrin, epidermal growth factor receptor (EGFR), laminin-1/5, collagen-IV, matrix metalloproteinase(MMPs), heparan sulfate proteoglycans, and others. Elevated circulating level of growth hormone and estrogen get to multipotent cap cells on TEB tips through a thin, leaky layer of basement membrane. These hormones promote specific gene expression. Hence cap cells can differentiate into myoepithelial and luminal (duct) epithelial cells, and the increased amount of activated MMPs can degrade surrounding ECM helping duct buds to reach further in the fat pads. On the other hand, basement membrane along the mature mammary ducts is thicker, with strong adhesion to epithelial cells via binding to integrin and non-integrin receptors. When side branches develop, it is a much more “pushing-forward” working process including extending through myoepithelial cells, degrading basement membrane and then invading into a periductal layer of fibrous stromal tissue. Degraded basement membrane fragments (laminin-5) roles to lead the way of mammary epithelial cells migration. Whereas, laminin-1 interacts with non-integrin receptor dystroglycan negatively regulates this side branching process in case of cancer. These complex "Yin-yang" balancing crosstalks between mammary ECM and epithelial cells "instruct" healthy mammary gland development until adult.
Ring-tailed lemur
Females have two pairs of mammary glands (four nipples), but only one pair is functional. The anterior pair (closest to the head) are very close to the axillae (armpit). Furless scent glands are present on both males and females. Both sexes have small, dark antebrachial (forearm) glands measuring 1 cm long and located on the inner surface of the forearm nearly above the wrist joint. (This trait is shared between the "Lemur" and "Hapalemur" genera.) The gland is soft and compressible, bears fine dermal ridges (like fingerprints), and is connected to the palm by a fine, 2 mm–high, hairless strip. However, only the male has a horny spur that overlays this scent gland. The spur develops with age through the accumulation of secretions from an underlying gland that may connect through the skin through as many as a thousand minuscule ducts. The males also have brachial (arm) glands on the axillary surface of their shoulders (near the armpit). The brachial gland is larger than the antebrachial gland, covered in short hair around the periphery, and has a naked crescent-shaped orifice near the center. The gland secretes a foul-smelling, brown, sticky substance. The brachial gland is barely developed if present at all in females. Both genders also have apocrine and sebaceous glands in their genital or perianal regions, which are covered in fur.
Parathyroid gland
Parathyroid glands are small endocrine glands in the neck of humans and other tetrapods that produce parathyroid hormone. Humans usually have four parathyroid glands, variably located on the back of the thyroid gland. Parathyroid hormone and calcitonin (one of the hormones made by the thyroid gland) have key roles in regulating the amount of calcium in the blood and within the bones.