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BIOL242
Pituitary Gland
Function
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 The pituitary is a small, bean-shaped gland located below the
brain in the skull base in an area called the pituitary fossa, or
sella turcica. Weighing less than one gram, the pituitary gland is
often called the "master gland" since it controls the secretion of
hormones.
 Hormones have a dramatic and broad range of effects on
metabolism, growth and maturation, sexuality and reproduction,
and other important bodily functions.
 The pituitary gland produces several hormones:
o Prolactin: stimulates breast milk production and controls
menstrual periods
o ACTH: signals the adrenal glands (situated atop the kidneys) to produce the steroid
cortisol
o Growth hormone (GH): signals special liver cells to produce somatomedin-C, which is
critical for body growth during childhood
o Thyroid stimulating hormone (TSH): signals the thyroid gland to produce thyroid hormone
which is essential for the regulation of body metabolism
o FSH and LH: regulate hormone production by the testes (testosterone) and ovaries
(estrogen, progesterone)
o ADH: stimulates the kidney concentrate the urine by taking up water back into the
bloodstream
Structure
 Structurally, the pituitary gland is divided
into a larger frontal region
(adenohypophysis) and a smaller
posterior region (neurohypophysis).
 The gland is connected to a region of
the brain called the hypothalamus by the
pituitary stalk. Directly above the
pituitary gland and in front of the pituitary
stalk are the crossing fibers of the optic
nerves, called the optic chiasm.
 On each side of the pituitary gland is the
cavernous sinus. Through each
cavernous sinus runs a carotid artery
that carries blood to the brain, and
important nerves that control eye
movements.
 Because of the close proximity of the pituitary gland to major intracranial nerves and blood
vessels, as well as the vital hormonal control the pituitary gland provides, disorders of the pituitary
can cause a wide spectrum of symptoms, both hormonal and neurological.
Pituitary Hormones
Listed below are the specific hormones produced by the pituitary. Hormone over production of deficiencies
can cause a host of symptoms:
 Thyroid Stimulating Hormone (TSH):
 Stimulates the thyroid gland to release thyroid hormones.
 Control basal metabolic rate and play an important role in growth and maturation.
 Affect almost every organ in the body.
 Growth Hormone (GH): Principal hormone that regulates growth.
 Adrenocorticotropic Hormone (ACTH): Triggers the adrenal glands, which regulate stress
response with the release of hormones such as cortisol and aldosterone.
 Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH): Control reproduction.
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BIOL242
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Pituitary Gland
Prolactin (PRL): Stimulates secretion of breast milk.
Vasopressin, also called anti-diuretic hormone (ADH): Promotes water retention.
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Photographs © 2003 by Alan Nyiri, courtesy of the Atkinson Photographic Archive, Stephanie Diani, ©
2006 Regents of the University of California
Notes, Add’l. Info.:
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