Chapter 1 Flashcards
Distinguish between endocrine and exocrine glands.
Endocrine: release directly into bloodstream
Exocrine: release into a duct that opens onto external or internal surfaces
hypothalamus function
produces hypophysiotropic hormones that control the anterior pituitary gland; in
addition, makes hormones that are stored in the posterior pituitary gland
pituitary gland function
also known as hypophysis; produces tropic hormones that regulate many of the other
endocrine glands
pineal gland function
produces melatonin, which is involved in rhythmic activities, such as daily
sleep-wake cycles
thyroid function
produces thyroxine, which regulates the rate of metabolism; essential to
normal growth and development; in addition, makes calcitonin, which lowers blood
calcium levels
parathyroid function
produces parathyroid hormone, which stimulates bone resorption and increases blood
calcium levels
thymus function
produces thymosin, which stimulates T cell development
pancreas function
produces insulin and glucagon, which regulate the level of glucose in the blood
adrenal cortex function
produces stress hormones that increase heart rate, blood pressure, and carbohydrate
and fat metabolism; in addition, makes hormones involved in sodium retention
ovaries function
produces estrogen and progesterone, which are involved in uterine and
mammary tissue development and female secondary sex characteristics; maintenance
of pregnancy
testes function
produces testosterone, which is responsible for spermatogenesis and male secondary
sex characteristics
Give several examples of how the endocrine system is complex.
A single endocrine gland can produce several hormones.
A single hormone may be secreted by more than one endocrine gland.
Not all endocrine organs are exclusively endocrine in function.
A single target cell may be influenced by more than one hormone.
A single hormone has more than one target cell (can induce more than one response).
Some bioregulators have overlapping roles (can act as a hormone, neurohormone, neurotransmitter, etc.)
Some hormones are under the direct influence of the pituitary (tropic) and the hypothalamus (hypophysiotropic).
A given hormone can be influenced by the concentrations of other hormones that interact with it (synergism, antagonism)
Pathologies can hypo- or hyper-secretion of a given hormone at the level of the hypothalamus (3), pituitary (2), or target organ (1)
What makes a cell a target cell for a hormone
the receptor molecule
neurocrines
A chemical signaling facilitated by the neurons or nerve cells
neurotransmitters
secreted by neurons into synapse (ACh, GABA)