gland
[gland] an aggregation of cells specialized to secrete or excrete materials not related to their ordinary metabolic needs. Glands are divided into two main groups, endocrine and exocrine. adj.,
adj glan´dular.
The
endocrine glands, or ductless glands, discharge their secretions (hormones) directly into the blood; they include the adrenal, pituitary, thyroid, and parathyroid glands, the islands of Langerhans in the pancreas, the gonads, the thymus, and the pineal body. The
exocrine glands discharge through ducts opening on an external or internal surface of the body; they include the salivary, sebaceous, and sweat glands, the liver, the gastric glands, the pancreas, the intestinal, mammary, and lacrimal glands, and the prostate. The
lymph nodes are sometimes called lymph glands but are not glands in the usual sense.

Classification of glands according to mode of secretion. From Applegate, 2000.
acinous gland one made up of one or more
acini (oval or spherical sacs).
apocrine gland one whose discharged secretion contains part of the secreting cells.
areolar g's Montgomery's glands.
axillary g's lymph nodes in the axilla.
Bartholin g's two small mucus-secreting glands, one on each side in the lower pole of the labium majus and connected to the surface by a duct lined with transitional cells, which opens just external to the hymenal ring. Their exact function is not clear but they are believed to secrete mucus to moisten the vestibule during sexual excitement. Called also major vestibular glands.
bronchial g's seromucous glands in the mucosa and submucosa of the bronchial walls.
Brunner's g's glands in the submucosa of the duodenum that secrete intestinal juice; called also duodenal glands.
buccal g's seromucous glands on the inner surface of the cheeks; called also genal glands.
bulbocavernous g's (bulbourethral g's) two glands embedded in the substance of the sphincter of the male urethra, posterior to the membranous part of the urethra; their secretion lubricates the urethra; called also Cowper's glands.
cardiac g's mucus-secreting glands of the cardiac part (cardia) of the stomach.
celiac g's lymph nodes anterior to the abdominal aorta.
ceruminous g's cerumin-secreting glands in the skin of the external auditory canal.
cervical g's 1. the lymph nodes of the neck.
2. compound clefts in the wall of the uterine cervix.
ciliary g's sweat glands that have become arrested in their development, situated at the edges of the eyelids; called also Moll's glands.
circumanal g's specialized sweat and sebaceous glands around the anus; called also Gay's glands.
Cobelli's g's mucous glands in the esophageal mucosa just above the cardia.
compound gland one made up of a number of smaller units whose excretory ducts combine to form ducts of progressively higher order.
Cowper's g's bulbourethral glands.
ductless g's endocrine glands.
duodenal g's Brunner's glands.
Ebner's g's serous glands at the back of the tongue near the taste buds.
endocrine g's see endocrine glands.
exocrine g's glands that discharge their secretions through ducts opening on internal or external surfaces of the body; see
gland.
fundic g's (fundus g's) numerous tubular glands in the mucosa of the fundus and body of the stomach that contain the cells that produce acid and pepsin.
gastric g's the secreting glands of the stomach, including the fundic, cardiac, and pyloric glands.
Gay's g's circumanal glands.
glossopalatine g's mucous glands at the posterior end of the smaller sublingual glands.
holocrine gland one whose discharged secretion contains the entire secreting cells.
intestinal g's straight tubular glands in the mucous membrane of the intestines, in the small intestine opening between the bases of the villi, and containing argentaffin cells. Called also
crypts or
glands of Lieberkühn.
jugular gland a lymph node behind the clavicular insertion of the sternocleidomastoid muscle.
Krause's gland an accessory lacrimal gland deep in the conjunctival connective tissue, mainly near the upper fornix.
lingual g's the seromucous glands on the surface of the tongue.
lingual g's, anterior seromucous glands near the apex of the tongue.
Littre's g's 2. the male urethral glands.
major vestibular g's Bartholin glands.
mammary gland a specialized gland of the skin of female mammals, which secretes milk for the nourishment of their young; it exists in a rudimentary state in the male. See also
breast.
meibomian g's sebaceous follicles between the cartilage and conjunctiva of the eyelids. Called also tarsal glands.
merocrine gland one whose discharged secretion contains no part of the secreting cells.
mixed g's 1. seromucous glands.
2. glands that have both exocrine and endocrine portions.
Moll's g's ciliary glands.
Montgomery's g's sebaceous glands in the mammary areola; called also areolar glands.
mucous g's glands that secrete mucus.
olfactory g's small mucous glands in the olfactory mucosa; called also Bowman's glands.
peptic g's gastric glands that secrete pepsin.
preputial g's small sebaceous glands of the corona of the penis and the inner surface of the prepuce, which secrete smegma; called also Littre's glands and Tyson's glands.
pyloric g's the mucin-secreting glands of the pyloric part of the stomach.
sebaceous gland a type of
holocrine gland of the corium that secretes an oily material (
sebum) into the hair follicles.

Glands: The relationship of the hair follicle, eccrine and apocrine sweat glands and sebaceous glands. From Copstead, 1995.
sentinel gland an enlarged lymph node, considered to be pathognomonic of some pathologic condition elsewhere.
seromucous g's glands that are both serous and mucous.
serous gland a gland that secretes a watery albuminous material, commonly but not always containing enzymes.
sex gland (
sexual gland)
gonad.
simple gland one with a nonbranching duct.
Skene's g's the largest of the female urethral glands, which open into the urethral orifice; they are regarded as homologous with the prostate. Called also paraurethral ducts.
solitary g's solitary follicles.
sublingual gland a salivary gland on either side under the tongue.
submandibular gland (
submaxillary gland) a salivary gland on the inner side of each
ramus of the mandible.
target gland any gland affected by a secretion or other stimulus from another gland, such as those affected by the secretions of the
pituitary gland.
tarsal g's meibomian glands.
tubular gland any gland made up of or containing a tubule or tubules.
unicellular gland a single cell that functions as a gland, e.g., a goblet cell.
urethral g's mucous glands in the wall of the urethra; in the male, called also Littre's glands.
uterine g's simple tubular glands found throughout the thickness and extent of the
endometrium; they become enlarged during the premenstrual period.
vesical g's mucous glands sometimes found in the wall of the urinary bladder, especially in the area of the trigone.
vulvovaginal g's Bartholin's glands.
Waldeyer's g's glands in the attached edge of the eyelid.
Weber's g's the tubular mucous glands of the tongue.
pituitary
[pĭ-tu´ĭ-tar″e] 1. pertaining to the pituitary gland.
3. a preparation of the pituitary glands of animals, used therapeutically.
pituitary gland an endocrine gland located at the base of the brain in a small recess of the sphenoid bone called the
sella turcica. It is attached by the hypophyseal stalk to the
hypothalamus and is divided into an anterior lobe (the
adenohypophysis) and a posterior lobe (the
neurohypophysis), which differ in embryological function and origin. Called also
hypophysis.
The
adenohypophysis originates from epithelial tissue. The adenohypophysis secretes six important hormones:
growth hormone,
thyroid-stimulating hormone or
thyrotropin,
adrenocorticotropic hormone or
corticotropin,
prolactin,
follicle-stimulating hormone, and
luteinizing hormone. Most of these hormones are
tropic hormones, which regulate the growth, development, and proper functioning of other endocrine glands and are of vital importance to the growth, maturation, and reproduction of the individual. Secretion of the anterior pituitary hormones is controlled by
releasing and
inhibiting hormones produced by the hypothalamus. Information gathered by the nervous system about the well-being of an individual is collected in the hypothalamus and used to control the secretion of hormones by the pituitary gland. The hypothalamic releasing and inhibiting hormones are transported to the pituitary gland by way of the hypothalamic-hypophyseal portal system in which the hypothalamic venules connect with the capillaries of the anterior pituitary.
The
neurohypophysis originates from neural tissue; it stores and secretes two hormones,
oxytocin and
vasopressin (
antidiuretic hormone). These hormones are synthesized in the cell bodies of neurons located in the hypothalamus and transported along the axons to the terminals located in the neurohypophysis and are released in response to neural stimulation.
Surgical removal of part or all of the pituitary gland is called
hypophysectomy and is usually done for treatment of a pituitary tumor. Because of its influence on the adrenal cortex and other endocrine glands, removal of the pituitary gland has widespread effects on the body. See
hypophysectomy.

The pituitary gland and its relationship to the hypothalamus.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.