BIOL 1080 Chapter Notes -Aldosterone, Anaphylaxis, Glycogen
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Chapter 3A (iv) - The Endocrine System
Endocrine glands: Made of secretory cells that release their products, called hormones.
Endocrine system: Consists of endocrine glands and of organs that contain some
Major glands are:
- Pituitary gland
- Thyroid gland
- Parathyroid gland
- Adrenal gland
- Pineal gland
Major organs with endocrine tissue are:
- Small intestine & Kidneys
Antagonistic interaction Effect of one hormone opposes that of another hormone.
Synergistic interaction the response of a tissue to a combination of two hormones is
much greater that its response to either individual hormone.
Permissive interaction one hormone must be present for another hormone to exert its
- Suspended from the base of the brain by a short stalk.
- Stalk connects the gland to the hypothalamus
o Area of the brain that regulates physiological responses. (Body temperature,
water balance, sleeping)
- Consists of anterior and posterior lobe
- 6 hormones
o Growth hormone (GH)
o Prolactin (PRL)
o Thyroid-stimulating hormone (TSH) acts on the thyroid gland to release
o Adrenocorticotropic hormone (ACTH) tropic hormone for adrenal gland
o Follicle-stimulating hormone (FSH) promotes development of egg cells and
secretion of the hormone estrogen from the ovaries
o Luteinizing hormone (LH) causes ovulation, release of future egg cell by
the ovary in female - secretes estrogen and progesterone
Tropic hormone: A hormone produced by one endocrine gland or hormone that
influences another endocrine gland.
- Anterior Lobe
o Circulatory connection
Growth Hormone (GH)
Stimulate growth through increasing in cell size and rate of cell division
Cells of bones, muscle and cartilage
Role in glucose conservation by making fats more available as a source of fuel
Too much leads to gigantism
Acromegaly - enlargement of tongue, and thickening in the bones of the hands, feet,
and face. (Happens during adulthood when bones can’t lengthen but thicken)
Dwarfism - not enough
Stimulates mammary gland to produce milk
Too much leads to sterility
- Posterior Lobe
o Neural connection
o Doesn’t produce hormone on its own
Antidiuretic hormone (ADH)
Conserve body water by decreasing urine output.
Not enough causes excessive urine production and resultant dehydration.
Stimulating the uterine contraction of childbirth.
Stimulate milk ejection
Thyroid Hormone (TH)
Regulates the body’s metabolic rate and production of heat.
Breakthrough of lipids
Use of glucose for production of ATP
Cretinism - not enough during fetal development - causes dwarfism and delayed
Too much - Graves’ disease - a person’s own immune system produced antibodies
that mimic the action of FSH.
Regulate the concentration of calcium in the blood to maintain proper functioning of
the muscles cells and neurons.