18.9 Secondary endocrine organs

Question 1

kidneys release..

Answer 1

calcitrol, erythropoietin, and renin

Question 2

calcitrol

stimulation, effects

Answer 2

steroid hormone secreted in response to PTH

• stimulates calcium and phosphate ion absorption along digestive tract
• stimulates formation of osteoprogenitor cells and osteoclasts
• stimulates Ca2+ reabsorption by kidneys
• suppresses PTH production

Question 3

EPO

stimulation, effects

Answer 3

erythropoietin

• released in response to low oxygen levels in kidney
• stimulates bone marrow to produce RBCs

Question 4

Renin

stimulation, effects

Answer 4

enzyme released in response to sympathetic stimulation or a decline in renal blood flow
-starts cascade: renin-angiotensin system (renin converts angiotensinogen to angiotensin I, which is modified to angiotensin II)

Question 5

angiotensin II

effects

Answer 5

stimulates secretion of aldosterone by adrenal cortex, and of ADH at posterior pituitary

• this restricts salt and water loss at kidneys
• stimulates thirst, elevates blood pressure

Question 6

natriuretic peptides (ANP & BNP)
stimulation, effects

Answer 6

• stimulated by large blood volume
• effects oppose angiotensin II (promote salt and water loss at kidneys
• inhibit secretion of renin, ADH and aldosterone, suppress thirst
• reduction in blood volume and blood pressure

Question 7

thymus

Answer 7

thymosin: promotes development of lymphocytes (WBCs responsible for immunity)

Question 8

interstitial cells of the testes

Answer 8

produce androgens

Question 9

nurse cells in the testes

Answer 9

support differentiation and maturation of sperm

Question 10

inhibin

Answer 10

secreted in response to FSH

-inhibits secretion of FSH & possible GnRH

Question 11

estrogens

Answer 11

produced in ovaries under FSH and LH stimulation

Question 12

principle progestin

Answer 12

progesterone

Question 13

GH malfunctions

Answer 13

underproduction: pituitary growth failure
overproduction: gigantism, acromegaly

Question 14

ADH/VP malfunctions

Answer 14

underproduction: diabetes insipidus
overproduction: SIADH (syndrome of inappropriate ADH secretion) - inc body weight & water content

Question 15

T4, T3 malfunctions

Answer 15

underproduction: myxedemia, cretinism (low metabolic rate, low body temp, impaired phys and mental development)
overproduction: hyperthyroidism, graves disease (high metabolic rate and body temp)

Question 16

PTH malfunctions

Answer 16

underproduction: hypoparathyroidism (muscle weakness, neurological problems, dense bones, tetany)
overproduction: hyperparathyroidism (neuro, mental, muscular problems due to high Ca2+, weak & brittle bones

Question 17

insulin malfunctions

Answer 17

underproduction: diabetes mellitus (type 1)
overproduction: excess insulin (low glucose, possibly causing coma)

Question 18

mineralcorticoids (MCs) malfunctions

Answer 18

underproduction: hypoaldosteronism (polyuria, low blood volume, high K+, low Na+
overproduction: aldosteronism (inc body weight due to high Na+ water retention, low K+)

Question 19

glucocorticoids (GCs) malfunctions

Answer 19

underproduction: Addison’s disease (inability to tolerate stress, mobilize energy reserves, or maintain normal glucose concentrations)
overproduction: Cushing’s disease (excessive breakdown of tissue proteins and lipid reserves, impaired glucose metabolism)

Question 20

E, NE malfunctions

Answer 20

overproduction: pheochromocytoma (high metabolic rate, body temp, and heart rate; elevated glucose levels)

Question 21

estrogens malfunctions

Answer 21

underproduction: hypogonadism (sterility, lack of secondary sex characteristics)
overproduction: adrenogenital syndrome (overproduction of androgens by zona reticularis of adrenal cortex, leads to masculinization), Precocious puberty (premature sexual maturation

Question 22

androgens malfunctions

Answer 22

underproduction: hypogonadism (sterility, lack of secondary sex characteristics)
overproduction: adrenogenital syndrome (abnormal production of estrogen due to adrenal or interstitial cell tumors, leads to breast enlargement), Precocious puberty (premature sexual maturation

Question 23

adipose tissue

Answer 23

produces leptin (feedback control of appetite)
-leptin must be present for normal levels of GnRH and gonadotropin synthesis

Question 24

growth requires which hormones?

Answer 24

GH, thyroid hormones (nervous system development before & after birth), insulin, PTH and calcitrol (for strong bones), and reproductive hormones

Question 25

general adaptation syndrome (GAS)

Answer 25

AKA: stress response.. 3 phases: alarm phase, resistance phase, and exhaustion phase

Question 26

Alarm phase

Answer 26

immediate response to stress.

• fight or flight..
• Epinephrine is dominant hormone
• inc alertness, energy usage, heart & respiratory rate, sweat secretion
• dec digestive activity and urine production
• circulation changes, mobilization of glycogen & lipid reserves

Question 27

Resistance phase

Answer 27

• long term stress response.. stress that lasts > a few hours
• conserve glucose
• conserve salts & water
• mobilize remaining energy reserves

Question 28

exhaustion phase

Answer 28

• begins after weeks or months of resistance phase
• exhaustion of lipid reserves
• structural or functional damage to vital organs
• inability to produce glucocorticoids
• failure of electrolyte imbalance
• fatal unless corrected immediately