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Related to anterior pituitary: thyroid gland, pituitary gland, adrenal gland
2. A preparation of dried, defatted, powdered anterior lobe of the pituitary gland of domestic animals.
See also: pituitary
anterior pituitaryendocrine gland, part of the pituitary gland at the base of the brain. Secretes growth hormone (with widespread actions on growth and metabolism), prolactin (promoting lactation) and 'trophic' hormones that regulate in turn the endocrine secretions of the adrenal cortex, of the thyroid gland, and those from the gonads involved in reproductive function. All these secretory functions are themselves controlled by 'releasing' and in some instances also 'inhibitory' hormones from the hypothalamus via local blood vessels. See also hormones, posterior pituitary; Table 1.
|Site of production||Name of hormone||Main targets||Involved in regulating:||Secretion controlled by:|
|Hypothalamus||Releasing and inhibiting hormones||Anterior pituitary (via local blood vessels)||Secretion of anterior pituitary hormones||Other brain regions; feedback re regulated hormones and their actions|
|Neurohormones released from posterior pituitary:|
|Oxytocin||Uterus, breasts||Labour and lactation||Afferent information from target organs|
|Antidiuretic hormone (ADH, vasopressin)||Kidneys||Water loss: ECF volume and osmolality||Hypothalamic osmoreceptors|
|Anterior pituitary||(Human) growth hormone (H)GH||Most cells||Growth and metabolism||Hypothalamic releasing and inhibiting hormones via local blood vessels|
|Thyroid-stimulating (TSH)||Thyroid gland||Thyroid secretions|
|Gonadotrophins||Ovary or testis||Germ cell maturation and hormone secretions|
|Adrenocorticotrophic (ACTH)||Adrenal cortex||Cortisol secretion|
|Pineal body||Melatonin||Widespread, including brain, thymus, etc.||Hypothalamus; varying light input from retina|
|Parathyroids||Parathormone||Bone, kidneys, gut||ECF [Ca2+]|
|Medulla||Heart, smooth muscle, glands||Cardiovascular and metabolic adjustments to activity and stress||Sympathetic nervous system|
|Atrial wall||Atrial natriuretic hormone||Kidneys||Blood volume; increases sodium (therefore also water) loss in urine||Stretch of atrial wall by venous pressure|
|Gonads: Testis||Androgens (mainly testosterone)||Genitalia and other tissues||Reproductive function and sex characteristics||Anterior pituitary gonadotrophins|
|Ovary||Uterus, breasts and other tissues||Menstrual cycle, pregnancy, lactation|
|Pancreas||Blood levels, storage and cellular uptake of nutrients, notably glucose, but also proteins and fats||Blood levels of nutrients; autonomic nervous system; other gastrointesinal hormones|
|Stomach||Gastrin||Gastric acid-secreting cells||Gastrointestinal functions: motility, digestive juices and other secretions||Local chemical and mechanical factors in the alimentary tract|
|Small intestine||Several GI functions including bile flow, pancreatic enzyme and exocrine secretions||Ingestion of food, distension of GI tract|
situated at or directed toward the front; opposite of posterior. In quadrupeds the use of the term is limited to parts of the head but is often used to mean cranially. In bipeds such as humans it is synonymous with ventral.
anterior abdomen pain
elicited pain in the anterior abdomen caused, in cattle, by reticulitis, hepatic or splenic abscess, abomasal ulcer and intestinal obstruction.
the part of the eyeball between the cornea and the iris, filled with aqueous humor.
anterior chamber angle
see iridocorneal angle.
chamber of the eye bounded by the iris and cornea; contains the aqueous humor as it moves to the filtration angle; called also anterior chamber.
anterior cruciate ligament
see cranial (anterior) cruciate ligament.
anterior (cranial) drawer sign
cranial, nonrotary movement of the proximal tibia in relation to the distal femur. Normally restricted by the cranial (anterior) cruciate ligament and used as a diagnostic test for rupture of that structure.
anterior epithelial layer
of the cornea is a noncornified, stratified, squamous epithelium, continuous with the bulbar conjunctival epithelium.
anterior functional stenosis
achalasia of the reticulo-omasal sphincter causing ingesta to accumulate in the reticulorumen.
anterior limiting membrane
of the cornea is a combination of the basement membrane, a felted layer of fine collagen fibers; substantial only in primates.
anterior pituitary hormones
anterior station trypanosomes
a section of the genus Trypanosoma in which the infectious stages accumulate in the mouthparts and salivary glands of the intermediate host so that the parasite is transmitted when the insect vector takes a blood meal. Called also Salivaria. See also posterior station trypanosomes.
anterior vena cava
see vena cava.