Endocrine Glands and Their
Hormones
(Anterior and Posterior Pituitary Glands)
Major Endocrine Glands and Structures
• 10 Major Glands of the Endocrine System
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Pituitary Gland
Hypothalamus
Thyroid Gland
Parathyroid Gland
Adrenal Gland
Pancreas
Testes
Ovaries
Thymus
Pineal Gland
Pituitary Gland
• Pituitary Gland: Is a small gland about the size of a
pea, located inferior to the hypothalamus in your brain.
It helps indirectly control and regulate the other major
endocrine glands.
• The Pituitary gland is broken into two parts:
▫ Anterior Pituitary
 Epithelial cells
▫ Posterior Pituitary
 Nerve cells
Hypothalamus and the Anterior Pituitary
Gland
• Stimuli with in the nervous
system cause releasing and
inhibiting hormones to be
secreted by the hypothalamus
• Releasing and inhibiting
hormones pass through the
hypothalamic-pituitary portal
• Releasing and inhibiting
hormones leave capillaries, and
bind to membrane-bound
receptors, and influence cells of
the anterior pituitary gland to
secrete hormones
• Anterior pituitary hormones
are carried in the blood to their
target tissue
Hypothalamus and the Posterior Pituitary
Gland
• Stimuli within the nervous
system stimulates the
hypothalamic nerve cells to
produce action potentials.
• Action potentials are carried to
the posterior pituitary gland.
Hormones are then stored in
the pituitary gland.
• Action potentials cause the
release of the stored hormones
into the circulatory system.
• Hormones travel to their target
tissues
Hormones of the Anterior Pituitary
• Growth Hormone (GH): Stimulates growth of bones,
muscles, and organs
▫ A deficiency of growth hormone can result in pituitary dwarfism
▫ A excess of growth hormone can results in giantism. If the
hormone is secreted after bone length is developed it will add to
the growth of the diameter of the bone. This is called acromegaly.
▫ Rhythm of GH secretion peaks during deep sleep
▫ GH increases during fasting and exercise
Hormones of the Anterior Pituitary
• Thyroid-Stimulating Hormone (TSH): Binds to
membrane-bound receptors on the thyroid gland and
causes them to secrete thyroid hormone.
▫ A decrease of TSH results in decrease in size of the thyroid
gland and less secretion of TSH.
▫ A increase of TSH results in the thyroid gland enlarging and
secreting to much TSH
Hormones of the Anterior Pituitary
• Adrenocorticotropic Hormone (ACTH): Binds to
membrane-bound receptors on cells in the cortex of the
adrenal glands.
▫ ACTH increases the secretion of cortisol also known as
hydrocortisone.
▫ ACTH prevents the adrenal cortex from degenerating.
▫ ACTH molecules bind to melanocytes in the skin and
increase pigmentation.
▫ To much ACTH can result in darkening of the skin
Hormones of the Anterior Pituitary
• Gonadotropin: Hormones that bind to
membrane-bound receptors on the cells of the
gonads and regulate growth, development and
function of the gonads.
• Luteinizing Hormone (LH): In females it
causes ovulation of oocytes and the secretion of
sex hormones. (estrogen and progesterone) in
males it stimulates testosterone and is referred to
as Interstitial cell-stimulating hormone (ICSH)
• Follicle-Stimulating Hormone (FSH):
Stimulates the development follicles in the ovaries
in females and sperm in the testes males.
Hormones of the Anterior Pituitary
• Prolactin: Binds to membrane-bound receptors in the
breast.
▫ Decrease of prolactin results in inability to produce breast
milk.
▫ Increase of prolactin results in production of breast milk
• Melanocyte-stimulating hormone (MSH): Bind to
melanocytes and causes them to synthesize melanin which
helps protect from UV light.
▫ Over secretion results in dark skin
▫ Inability to secrete results in fair skin
Hormones of the Posterior Pituitary
• Antidiuretic Hormone (ADH): Binds to membranebound receptors and increases water reabsorption by
kidneys tubules. Which results in less water lost as urine.
▫ ADH can cause blood vessels to constrict (vasopressin)
▫ Lack of ADH causes production of large amounts of dilute
urine.
▫ Alcohol can affect ADH levels
Hormones of the Posterior Pituitary
• Oxytocin: Binds to membrane-bound receptors, and
causes contraction of smooth muscle cells of the uterus
as well as milk letdown from the breast in lactating
women.
▫ Pitocin is a commercial preparation of oxytocin,
which help assist in child birth.