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DictionarySeesuprarenal glandMedicalSeePITUITARY GLAND: Hormones secreted by the anterior and posterior pituitary gland, along with target organs pituitary glandA small, gray, rounded gland that develops from ingrown oral epithelium (Rathke pouch) and is attached to the lower surface of the hypothalamus by the infundibular stalk. The Rathke pouch portion forms the anterior lobe and an intermediate area; the neural tissue of the infundibular stalk forms the posterior lobe. The pituitary gland averages 1.3 × 1.0 ×0.5 cm in size and weighs 0.55 to 0.6 g. Synonym: hypophysis; hypophysis cerebri See: illustrationFunctionThe pituitary is an endocrine gland secreting a number of hormones that regulate many bodily processes including growth, reproduction, and other metabolic activities. It is often referred to as the “master gland of the body.” Hormones are secreted in the following lobes: Intermediate lobe: In cold-blooded animals, intermedin is secreted, influencing the activity of pigment cells (chromatophores) of fishes, amphibians, and reptiles. In warm-blooded animals, no effects are known. Anterior lobe: Secretions here are the somatotropic, or growth hormone (STH or GH), which regulates cell division and protein synthesis for growth; adrenocorticotropic hormone (ACTH), which regulates functional activity of the adrenal cortex; thyrotropic hormone (TTH or TSH), which regulates functional activity of the thyroid gland; and prolactin, also called lactogenic hormone, which induces secretion of milk in the adult female. The gonadotropic hormones are as follows: in women, follicle-stimulating hormone (FSH) stimulates development of ovarian follicles and their secretion of estrogen; in men, it stimulates spermatogenesis in the testes. In women, luteinizing hormone (LH) stimulates ovulation and formation of the corpus luteum and its secretion of estrogen and progesterone. In men, LH also called interstitial cell-stimulation hormone (ICSH), stimulates testosterone secretion. Posterior lobe: Hormones are secreted by the neurosecretory cells of the hypothalamus and pass through fibers of the supraopticohypophyseal tracts in the infundibular stalk to the neurohypophysis, where they are stored. Secretions here are oxytocin, which acts specifically on smooth muscle of the uterus, increasing tone and contractility, and antidiuretic hormone (ADH), which increases reabsorption of water by the kidney tubules. In large amounts, ADH also causes vasoconstriction, and is also called vasopressin. DisordersHypersecretion of anterior lobe causes gigantism, acromegaly, and pituitary basophilism (Cushing disease). Hyposecretion of anterior lobe causes dwarfism, pituitary cachexia (Simmonds disease), Sheehan syndrome, acromicria, eunuchoidism, or hypogonadism. Posterior lobe deficiency or hypothalamic lesion causes diabetes insipidus. Anterior and posterior lobe deficiency and hypothalamic lesion cause Fröhlich syndrome (adiposogenital dystrophy) and pituitary obesity. preputial glandA modified sebaceous gland located on the neck of the penis and the inner surface of the prepuce; its secretion is a component of smegma. Synonym: Tyson glandprostate glandThe gland in the male that surrounds the neck of the bladder and the urethra. It is partly glandular, with ducts opening into the prostatic portion of the urethra, and partly muscular. It secretes a thin, opalescent, slightly alkaline fluid that forms part of the semen. The prostate consists of a median lobe and two lateral lobes measuring about 2 × 4 × 3 cm and weighing about 20 g; it is enclosed in a fibrous capsule containing smooth muscle fiber in its inner layer. The nerve supply is from the inferior hypogastric plexus. pyloric glandA gastric gland in the pyloric region of the stomach. racemose glandAcinar gland.Rivinus gland See: Rivinus, August Quirinus SALIVARY GLANDSsalivary glandAny of the glands near the oral cavity that secrete saliva. The major glands are paired and include the parotid, the sublingual, and the submandibular. There are numerous minor salivary glands in the oral cavity, named according to their locations: lingual, sublingual, palatal, buccal, labial, and glossopharyngeal. See: illustrationSalivary secretion is under nervous control, reflexly initiated by mechanical, chemical, or radiant stimuli acting on taste buds in the mouth, olfactory receptors, or the eyes. Secretion may also be due to conditioned reflexes as when one thinks about food or hears a dinner bell. The nerve supply of the salivary glands is from the facial and glossopharyngeal nerves, which increase secretion, and from the sympathetic nerves, which decrease secretion. The blood supply is from branches of the external carotid artery. sebaceous glandAn oil-secreting gland of the skin. The glands are simple or branched alveolar glands, most of which open into hair follicles. They are holocrine glands whose secretion arises from the disintegration of cells filling the alveoli. Some aberrant glands are found in the cheeks or lips of the oral cavity, well separated from hair follicles. See: Fordyce diseasesentinel glandA term formerly used to indicate a sentinel lymph node, i.e., a lymph node that first alerts a clinician to serious pathology (such as a spreading cancer).seromucous glandA mixed serous and mucus gland.serous glandAn exocrine gland with a relatively watery secretion, isotonic with blood plasma, and containing enzymes, glycoproteins, lysozymes, and bactericides. Serous glands are most common in the gastrointestinal tract, notably in the salivary glands. sex glandAn ovary or testis.simple gland A gland shaped like a single unbranched sac. When the sac is cylindrical, the gland is called simple tubular; when the sac is flask-shaped, the gland is called simple alveolar. Skene gland See: Skene, Alexanderstomach glandGastric gland.sublingual glandThe smallest of the major salivary glands, located in the tissue in the floor of the mouth between the tongue and mandible on each side. It is a mixed seromucous gland. Its main duct opens into or near the submandibular duct, but several smaller ducts may open to the oral cavity independently along the sublingual fold. Numerous minor sublingual glands are scattered throughout the mucosa under the tongue, each with its own duct to the oral surface. submandibular glandA mixed tubuloalveolar salivary gland about the size of a walnut that lies below the posterior floor of the mouth, medial to the body of the mandible. Its main duct (Wharton duct) opens at the side of the frenulum linguae. sudoriferous glandAny of the glands in the skin that secrete perspiration. See: sweat glands for illussuprarenal glandAdrenal gland. ECCRINE AND APOCRINE SWEAT GLANDSsweat glandAny of the simple, coiled, tubular glands found on all body surfaces except the margin of the lips, glans penis, and inner surface of the prepuce. The coiled secreting portion lies in the corium or subcutaneous portion of skin; the secretory duct follows a straight or oblique course through the dermis but becomes spiral in passing through the epidermis to its opening, a sweat pore. Most sweat glands are merocrine; those of the axilla, areola, mammary gland, labia majora, and circumanal region are apocrine. Sweat glands are most numerous on the palms of the hands and soles of the feet. See: illustration; apocrine gland; eccrine glandsynovial glandAny of the glands that project from the surface of the synovial tissue into the joint space and secrete synovial fluid.target glandAny gland affected by the action or secretion of another gland, e.g., the thyroid is a target gland of the pituitary. tarsal glandMeibomian gland.thymus gland See: thymus THYROID GLANDthyroid glandA large endocrine gland located in the center of the base of the neck. The gland is composed of two lobes, one on each side of the trachea, and an isthmus of tissue connecting the lower two thirds of each lobe. The isthmus is usually located at the level of the second to third tracheal rings. The whole gland is surrounded by a thin fibrous capsule attached in back to the cricoid cartilage and the first few tracheal rings. The lobes of the thyroid lie under the sternothyroid and sternohyoid muscles. The thyroid is filled with capillary networks (supplied by the superior and inferior thyroid arteries) that surround the many spherical units (follicles) packed inside the gland. Thyroid follicles consist of a ring of follicular cells surrounding a space filled with a clear colloid (a mixture of thyroglobulin proteins and iodine), from which the thyroid hormones (thyroxine and related molecules) are synthesized. These hormones regulate the rate of cellular metabolism throughout the body. All the steps in synthesizing and releasing thyroid hormones are stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland. Another class of thyroid cells, the parafollicular or C cells, is found outside the follicles; C cells secrete calcitonin, a calcium-lowering hormone. See: illustrationtracheal glandAny of the acinar glands of the tracheal mucosa. tubular glandA multicellular gland in which the cells secrete specific molecules into a cylindrical sac.Tyson glandPreputial gland.unicellular glandA lone secretory epithelial cell, often found in the midst of nonsecretory cells. A common example is the goblet (chalice, calceiform) cell, a unicellular mucous-secreting gland found in the columnar epithelium of the intestinal tract. urethral glandLittré gland.uterine glandAny of the tubular glands in the endometrium. vaginal glandAny of the alveolar glands found in the uppermost portion of the vaginal mucosa near the cervix, most of the vaginal mucosa being devoid of glands.vestibular glandAny of the glands of the vaginal vestibule. They include the minor vestibular glands and the major vestibular glands (Bartholin glands). von Ebner glandAny of the lingual salivary glands in the circumvallate papillae.vulvovaginal gland See: Bartholin gland Bartholin, Caspar (the younger)Waldeyer gland See: Waldeyer-HartzWeber gland See: Weber, Moritz I.glands of ZeisSmall sebaceous glands surrounding the follicles of eyelashes. Their lipid-rich secretions coat the shafts of lashes. su·pra·re·nal gland (sū'pră-rē'năl gland) [TA] A flattened, roughly triangular body positioned in relation to the superior end of each kidney but attached primarily to the diaphragmatic crura.
Synonym(s): adrenal body, adrenal gland. ">suprarenal gland pituitary gland, along with target organs " href="javascript:eml2('davisTab', 'g13.jpg')"> PITUITARY GLAND: Hormones secreted by the anterior and posterior pituitary gland, along with target organs pituitary glandA small, gray, rounded gland that develops from ingrown oral epithelium (Rathke pouch) and is attached to the lower surface of the hypothalamus by the infundibular stalk. The Rathke pouch portion forms the anterior lobe and an intermediate area; the neural tissue of the infundibular stalk forms the posterior lobe. The pituitary gland averages 1.3 × 1.0 ×0.5 cm in size and weighs 0.55 to 0.6 g. Synonym: hypophysis; hypophysis cerebri See: illustrationFunctionThe pituitary is an endocrine gland secreting a number of hormones that regulate many bodily processes including growth, reproduction, and other metabolic activities. It is often referred to as the “master gland of the body.” Hormones are secreted in the following lobes: Intermediate lobe: In cold-blooded animals, intermedin is secreted, influencing the activity of pigment cells (chromatophores) of fishes, amphibians, and reptiles. In warm-blooded animals, no effects are known. Anterior lobe: Secretions here are the somatotropic, or growth hormone (STH or GH), which regulates cell division and protein synthesis for growth; adrenocorticotropic hormone (ACTH), which regulates functional activity of the adrenal cortex; thyrotropic hormone (TTH or TSH), which regulates functional activity of the thyroid gland; and prolactin, also called lactogenic hormone, which induces secretion of milk in the adult female. The gonadotropic hormones are as follows: in women, follicle-stimulating hormone (FSH) stimulates development of ovarian follicles and their secretion of estrogen; in men, it stimulates spermatogenesis in the testes. In women, luteinizing hormone (LH) stimulates ovulation and formation of the corpus luteum and its secretion of estrogen and progesterone. In men, LH also called interstitial cell-stimulation hormone (ICSH), stimulates testosterone secretion. Posterior lobe: Hormones are secreted by the neurosecretory cells of the hypothalamus and pass through fibers of the supraopticohypophyseal tracts in the infundibular stalk to the neurohypophysis, where they are stored. Secretions here are oxytocin, which acts specifically on smooth muscle of the uterus, increasing tone and contractility, and antidiuretic hormone (ADH), which increases reabsorption of water by the kidney tubules. In large amounts, ADH also causes vasoconstriction, and is also called vasopressin. DisordersHypersecretion of anterior lobe causes gigantism, acromegaly, and pituitary basophilism (Cushing disease). Hyposecretion of anterior lobe causes dwarfism, pituitary cachexia (Simmonds disease), Sheehan syndrome, acromicria, eunuchoidism, or hypogonadism. Posterior lobe deficiency or hypothalamic lesion causes diabetes insipidus. Anterior and posterior lobe deficiency and hypothalamic lesion cause Fröhlich syndrome (adiposogenital dystrophy) and pituitary obesity. preputial glandA modified sebaceous gland located on the neck of the penis and the inner surface of the prepuce; its secretion is a component of smegma. Synonym: Tyson glandprostate glandThe gland in the male that surrounds the neck of the bladder and the urethra. It is partly glandular, with ducts opening into the prostatic portion of the urethra, and partly muscular. It secretes a thin, opalescent, slightly alkaline fluid that forms part of the semen. The prostate consists of a median lobe and two lateral lobes measuring about 2 × 4 × 3 cm and weighing about 20 g; it is enclosed in a fibrous capsule containing smooth muscle fiber in its inner layer. The nerve supply is from the inferior hypogastric plexus. pyloric glandA gastric gland in the pyloric region of the stomach. racemose glandAcinar gland.Rivinus gland See: Rivinus, August QuirinusSALIVARY GLANDSsalivary glandAny of the glands near the oral cavity that secrete saliva. The major glands are paired and include the parotid, the sublingual, and the submandibular. There are numerous minor salivary glands in the oral cavity, named according to their locations: lingual, sublingual, palatal, buccal, labial, and glossopharyngeal. See: illustrationSalivary secretion is under nervous control, reflexly initiated by mechanical, chemical, or radiant stimuli acting on taste buds in the mouth, olfactory receptors, or the eyes. Secretion may also be due to conditioned reflexes as when one thinks about food or hears a dinner bell. The nerve supply of the salivary glands is from the facial and glossopharyngeal nerves, which increase secretion, and from the sympathetic nerves, which decrease secretion. The blood supply is from branches of the external carotid artery. sebaceous glandAn oil-secreting gland of the skin. The glands are simple or branched alveolar glands, most of which open into hair follicles. They are holocrine glands whose secretion arises from the disintegration of cells filling the alveoli. Some aberrant glands are found in the cheeks or lips of the oral cavity, well separated from hair follicles. See: Fordyce diseasesentinel glandA term formerly used to indicate a sentinel lymph node, i.e., a lymph node that first alerts a clinician to serious pathology (such as a spreading cancer).seromucous glandA mixed serous and mucus gland.serous glandAn exocrine gland with a relatively watery secretion, isotonic with blood plasma, and containing enzymes, glycoproteins, lysozymes, and bactericides. Serous glands are most common in the gastrointestinal tract, notably in the salivary glands. sex glandAn ovary or testis.simple gland A gland shaped like a single unbranched sac. When the sac is cylindrical, the gland is called simple tubular; when the sac is flask-shaped, the gland is called simple alveolar. Skene gland See: Skene, Alexanderstomach glandGastric gland.sublingual glandThe smallest of the major salivary glands, located in the tissue in the floor of the mouth between the tongue and mandible on each side. It is a mixed seromucous gland. Its main duct opens into or near the submandibular duct, but several smaller ducts may open to the oral cavity independently along the sublingual fold. Numerous minor sublingual glands are scattered throughout the mucosa under the tongue, each with its own duct to the oral surface. submandibular glandA mixed tubuloalveolar salivary gland about the size of a walnut that lies below the posterior floor of the mouth, medial to the body of the mandible. Its main duct (Wharton duct) opens at the side of the frenulum linguae. sudoriferous glandAny of the glands in the skin that secrete perspiration. See: sweat glands for illussuprarenal glandAdrenal gland.ECCRINE AND APOCRINE SWEAT GLANDSsweat glandAny of the simple, coiled, tubular glands found on all body surfaces except the margin of the lips, glans penis, and inner surface of the prepuce. The coiled secreting portion lies in the corium or subcutaneous portion of skin; the secretory duct follows a straight or oblique course through the dermis but becomes spiral in passing through the epidermis to its opening, a sweat pore. Most sweat glands are merocrine; those of the axilla, areola, mammary gland, labia majora, and circumanal region are apocrine. Sweat glands are most numerous on the palms of the hands and soles of the feet. See: illustration; apocrine gland; eccrine glandsynovial glandAny of the glands that project from the surface of the synovial tissue into the joint space and secrete synovial fluid.target glandAny gland affected by the action or secretion of another gland, e.g., the thyroid is a target gland of the pituitary. tarsal glandMeibomian gland.thymus gland See: thymusTHYROID GLANDthyroid glandA large endocrine gland located in the center of the base of the neck. The gland is composed of two lobes, one on each side of the trachea, and an isthmus of tissue connecting the lower two thirds of each lobe. The isthmus is usually located at the level of the second to third tracheal rings. The whole gland is surrounded by a thin fibrous capsule attached in back to the cricoid cartilage and the first few tracheal rings. The lobes of the thyroid lie under the sternothyroid and sternohyoid muscles. The thyroid is filled with capillary networks (supplied by the superior and inferior thyroid arteries) that surround the many spherical units (follicles) packed inside the gland. Thyroid follicles consist of a ring of follicular cells surrounding a space filled with a clear colloid (a mixture of thyroglobulin proteins and iodine), from which the thyroid hormones (thyroxine and related molecules) are synthesized. These hormones regulate the rate of cellular metabolism throughout the body. All the steps in synthesizing and releasing thyroid hormones are stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland. Another class of thyroid cells, the parafollicular or C cells, is found outside the follicles; C cells secrete calcitonin, a calcium-lowering hormone. See: illustrationtracheal glandAny of the acinar glands of the tracheal mucosa. tubular glandA multicellular gland in which the cells secrete specific molecules into a cylindrical sac.Tyson glandPreputial gland.unicellular glandA lone secretory epithelial cell, often found in the midst of nonsecretory cells. A common example is the goblet (chalice, calceiform) cell, a unicellular mucous-secreting gland found in the columnar epithelium of the intestinal tract. urethral glandLittré gland.uterine glandAny of the tubular glands in the endometrium. vaginal glandAny of the alveolar glands found in the uppermost portion of the vaginal mucosa near the cervix, most of the vaginal mucosa being devoid of glands.vestibular glandAny of the glands of the vaginal vestibule. They include the minor vestibular glands and the major vestibular glands (Bartholin glands). von Ebner glandAny of the lingual salivary glands in the circumvallate papillae.vulvovaginal gland See: Bartholin gland Bartholin, Caspar (the younger)Waldeyer gland See: Waldeyer-HartzWeber gland See: Weber, Moritz I.glands of ZeisSmall sebaceous glands surrounding the follicles of eyelashes. Their lipid-rich secretions coat the shafts of lashes. su·pra·re·nal gland (sū'pră-rē'năl gland) [TA] A flattened, roughly triangular body positioned in relation to the superior end of each kidney but attached primarily to the diaphragmatic crura.
Synonym(s): adrenal body, adrenal gland. |