EXAM 3- ENDOCRINE SYSTEM
QUESTIONS AND ANSWERS
hypothalamus - ANSWER--essential for biological survival
-acts as sensor in several homeostatic mechanisms
-produces appropriate behavioral response
-secretes appropriate hormone
*sensitive to temperature -->regulates metabolism
*monitors: blood glucose, Na+ (drinking, thirst), testosterone (sex), adenosine levels
(sleep)
posterior pituitary gland - ANSWER--doesn't have hormone--> produce endocrine
cells
-neuroendocrine cells produce hormone
*in hypothalamus, extend to the posterior pituitary gland
*produce ADH & oxytocin
*released when neuroendocrine cells send pulses from hypothalamus
anterior pituitary gland - ANSWER--to stimulate anterior pituitary-->neuroendocrine
cells make Releasing Hormones & Inhibiting Hormones
-RH travel through Pituitary Portal Blood System directly to anterior pituitary
-stimulates release of hormone from anterior pituitary
Hypothalamus-->AnteriorPituitary-->StimulatingHormone or Thyroid/Tropic
Hormone-->Glands
Temperature Regulation - ANSWER--Thyroid=part of thermoregulation mechanism
-produces Thyroxine (requires iodine for production)
*increases metabolic rate by causing body cells to make ATP from glucose
-regulated by Hypothalamus & Anterior Pituitary hormones
Hypotalamus (Thyrotropin Releasing Horomone is secreted)--> AnteriorPituitary--
>Thryoid Stimulating Hormone--> Thyroid-->Thyroxine-->Body cells
*Negative Feedback Loop
goiter - ANSWER--iodine deficiency; iodine needed to make Thyroxine
-Negative Feedback inhibition of TRH from Hypothalamus & TSH from Anterior
Pituitary is affected
*continues stimulation to Thyroid-->causes swelling
hypothyroidism - ANSWER--too little Thyroxine
Possible Causes:
1. insufficient secretion of: thyroxine, TSH, TRH
2. iodine deficiency
Treatments??
1. hormone supplements to replace missing hormone
2. more iodine in diet (like iodized salts)
hyperthyroidism - ANSWER-Possible Causes:
, 1. tumor in gland-->overproduction of hormone (thyroid, anterior pituitary,
hypothalamus)
2. most common= Grave's Disease
*autoimmune disorder
*person's antibodies stimulate thyroid-->too much thyroxine
Treatments??
1. drug that inhibits synthesis of thyroxine by inhibiting iodine uptake by thyroid
2. drug that blocks receptors for thyroxine
endocrine system - ANSWER--makes hormones that are used for communication
b/w cells in distant parts of the body
hormones - ANSWER--chemical messengers made by endocrine glands
-circulate in bloodstream
-act on specific cells in body ("target cells") that have a receptor for that hormone
endocrine glands - ANSWER--ductless organs that secret hormones into the blood
-pituitary gland, testes & ovaries, thyroid, adrenal glands, etc.
Functions - ANSWER-1. Development
2. Homeostasis
development (function) - ANSWER--maturation & puberty
-growth & cell division stimulated by chemical signals (mitogens)
-differentiation of a cell depends on what chemical signal it receives
-reproduction; production of gametes & sexual behavior are hormonally regulated
homeostasis (function) - ANSWER--maintenance of constant, optimal internal
environment
ex: body temperature, blood pH, blood glucose & pressure & heartbeat
Endocrine vs. Nervous- similarities - ANSWER--both use chemical signals to
communicate
-both types of chemical signals must be received by receptors with a specific shape
(lock & key)
-there's an interaction b/w endocrine & nervous system
Endocrine- differences - ANSWER--chemical signal=hormone
-slow acting (relatively)
-travels through blood & can reach all parts of the body
-diffuses out of blood into tissue fluids @ some distant location
Nervous- differences - ANSWER--chemical signal=neurotransmitter
-very fast acting
-released @ point of contact b/w 2 nerve cells (synapses); not in blood
-can't signal over long distance
Negative Feedback Loop - ANSWER--maintains homeostasis
ex:
-Controlled Variable=blood sugar levels
QUESTIONS AND ANSWERS
hypothalamus - ANSWER--essential for biological survival
-acts as sensor in several homeostatic mechanisms
-produces appropriate behavioral response
-secretes appropriate hormone
*sensitive to temperature -->regulates metabolism
*monitors: blood glucose, Na+ (drinking, thirst), testosterone (sex), adenosine levels
(sleep)
posterior pituitary gland - ANSWER--doesn't have hormone--> produce endocrine
cells
-neuroendocrine cells produce hormone
*in hypothalamus, extend to the posterior pituitary gland
*produce ADH & oxytocin
*released when neuroendocrine cells send pulses from hypothalamus
anterior pituitary gland - ANSWER--to stimulate anterior pituitary-->neuroendocrine
cells make Releasing Hormones & Inhibiting Hormones
-RH travel through Pituitary Portal Blood System directly to anterior pituitary
-stimulates release of hormone from anterior pituitary
Hypothalamus-->AnteriorPituitary-->StimulatingHormone or Thyroid/Tropic
Hormone-->Glands
Temperature Regulation - ANSWER--Thyroid=part of thermoregulation mechanism
-produces Thyroxine (requires iodine for production)
*increases metabolic rate by causing body cells to make ATP from glucose
-regulated by Hypothalamus & Anterior Pituitary hormones
Hypotalamus (Thyrotropin Releasing Horomone is secreted)--> AnteriorPituitary--
>Thryoid Stimulating Hormone--> Thyroid-->Thyroxine-->Body cells
*Negative Feedback Loop
goiter - ANSWER--iodine deficiency; iodine needed to make Thyroxine
-Negative Feedback inhibition of TRH from Hypothalamus & TSH from Anterior
Pituitary is affected
*continues stimulation to Thyroid-->causes swelling
hypothyroidism - ANSWER--too little Thyroxine
Possible Causes:
1. insufficient secretion of: thyroxine, TSH, TRH
2. iodine deficiency
Treatments??
1. hormone supplements to replace missing hormone
2. more iodine in diet (like iodized salts)
hyperthyroidism - ANSWER-Possible Causes:
, 1. tumor in gland-->overproduction of hormone (thyroid, anterior pituitary,
hypothalamus)
2. most common= Grave's Disease
*autoimmune disorder
*person's antibodies stimulate thyroid-->too much thyroxine
Treatments??
1. drug that inhibits synthesis of thyroxine by inhibiting iodine uptake by thyroid
2. drug that blocks receptors for thyroxine
endocrine system - ANSWER--makes hormones that are used for communication
b/w cells in distant parts of the body
hormones - ANSWER--chemical messengers made by endocrine glands
-circulate in bloodstream
-act on specific cells in body ("target cells") that have a receptor for that hormone
endocrine glands - ANSWER--ductless organs that secret hormones into the blood
-pituitary gland, testes & ovaries, thyroid, adrenal glands, etc.
Functions - ANSWER-1. Development
2. Homeostasis
development (function) - ANSWER--maturation & puberty
-growth & cell division stimulated by chemical signals (mitogens)
-differentiation of a cell depends on what chemical signal it receives
-reproduction; production of gametes & sexual behavior are hormonally regulated
homeostasis (function) - ANSWER--maintenance of constant, optimal internal
environment
ex: body temperature, blood pH, blood glucose & pressure & heartbeat
Endocrine vs. Nervous- similarities - ANSWER--both use chemical signals to
communicate
-both types of chemical signals must be received by receptors with a specific shape
(lock & key)
-there's an interaction b/w endocrine & nervous system
Endocrine- differences - ANSWER--chemical signal=hormone
-slow acting (relatively)
-travels through blood & can reach all parts of the body
-diffuses out of blood into tissue fluids @ some distant location
Nervous- differences - ANSWER--chemical signal=neurotransmitter
-very fast acting
-released @ point of contact b/w 2 nerve cells (synapses); not in blood
-can't signal over long distance
Negative Feedback Loop - ANSWER--maintains homeostasis
ex:
-Controlled Variable=blood sugar levels
