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A&P.chap18.adrenal
| Question | Answer |
|---|---|
| adrenal medulla arises from | neural crest cells; which also give rise to postganlionic neuron of the sympathetic division |
| adrenal cortex is derived from | mesoderm |
| adrenal cortex is composed of three zones | zona glomerulasa, zona fasciculata and zona reticularis |
| adrenal medulla secretes | epinephrine and norepinephrine |
| why are epinephrine & norepinephrine considered neurohormones? | because adrenal medulla consists of same cells as postganglionic sympathetic neurons |
| 3 secretions of adrenal cortex | mineralocorticoids; glucocorticoids; and androgens |
| adrenal cortex - all 3 secretions are similar | because they are steroids; highly specialized lipids drevied from cholesterol - |
| hormones of the adrenal cortex bind to | intracellular receptors-stimulate syntheseis of specific proteins - then cell responds |
| epinephrine does what?? | increases blood levels of glucose |
| how does epinephrine work? | combines with membrane-bound recpetor in liver cells; then liver catazlyze the breakdown of glycogen to glucose--then release glucose from the liver cells into the blood |
| secretion of adrenal medullary hormones prepares the individual | for physical activity - is a major component of the fight-or-flight response |
| how long do effects of epinephrine last? | measured in minutes |
| what causes release of adrenal medullary hormones? | stress, physical activity & low blood glucose levels |
| adrenal medulla is a specialized part | of the autonomic nervous system |
| purpose of endocrine system (8) | ion regulation; metabolism; water balance; immune system regulation; heart rate & blood pressure regulation; control og blood glucose; control of reproductive function; uterine contraction & milk release |
| Lab - hypothalamus | most inferior portion of diencephalon |
| hypophyseal portal system | extends from part of hypothalamus to the anterior pituitary - carries hormones to anterior pituitary |
| positive and negative feedback | the body seeks to maintain homeostasis; negative feedback is a mechanism whereby any deviation from the set point is made smaller or is resisted |
| positive feedback | when a deviation from a normal value occurs, the response of the system is to make the deviation even greater - ex. birth another example extreme blood loss causes blood pressure to drop |
| diabetes insipidus | chronic excretion of very large amounts of pale urine of low specia gravity, causing dehydration and extreme thirs; results from inadequate output of antidiuretic hormone; the hypothalamus sends to posterior pituitary |
| which part of the pituitary is an extension of the hypothalamus? | exterior pituitary |
| describe the embryonic origin of the adenohypophsis and neurohyopophysis | extension of hypothalamus |
| what is the functions of thyroid follicle cell | storage of thyroglobin; which stores thyroid hormones |
| describe in words location of thyroid | two lobes of tissue, connected by an isthmus, lateral to upper portion of trachea; inferior to hyoid bone |
| when looking at slide of thyroid gland | open areas are thyroid follicles containg thyroblobulin COLLOID - the follicular cells surrounding the open area is a distinct area and PARAFOLLICULAR CELLS look like little feathers (they are lower right on the slide in book) |