Endocrine System: Adrenal Gland

what are the 3 layers of cortical cells and what corticosteroids do they produce

1. Zona glomerulosa - Mineralocorticoids (aldosterone)

2. Zona fasciculata. - Glucocorticoids

3. Zona reticularis. - Gonadocorticoids (weak androgens)

mineralocorticoids function (aldosterone)

regulates electrolyte concentrations (primarily NA+ and K+)

-- IMPORTANCE OF NA: affects ECF volume, blood volume, and pressure

WHERE SODIUM GOIS, WATER FLOWS

-- IMPORTANCE OF K+: sets resting membrane potential

ALDOSTERONE: reduces excretion of NA+ from out the body

--stimulates NA+ reabsorption by kidneys

--stimulates K+ elimination by kidneys

aldosterone function

decreases sodium and water loss in urine by returning sodium and water to the blood

what are the 4 factors that regulate aldosterone secretion

1. renin-angiotensin-aldosterone mechanism

2. plasma concentration of K+

3. ACTH

4. Atrial natriuretic peptide

what is the renin-angiotensin-aldosterone mechanism

1. blood pressure drops

2. renin is released from nephron of the kidney

3. renin produces angiotensin II

4. Angiotensin II activates aldosterone release

5. aldosterone induces sodium reabsorption, followed by water reabsorption

6. BLOOD VOLUME AND BLOOD PRESSURE INCREASE

what is the effect of renin-angiotensin-aldosterone release, plasma concentration of K, and adrenocorticotropic hormone

BV and BP increase

what is the effect of atrial natriuretic peptide

BV and BP decrease

what is reabsorption

when a substance is leaving the nephron tubules and is re-entering the blood stream

how does ACTH control aldosterone release

hypothalamus is part of limbic (emotional) system

- stress activates hypothalamus

- corticotropin releasing hormone is activated

- CRH activates ACTH

- ACTH travels to adrenal gland and induces release of aldosterone

how does atrial natriuretic peptide (ANP) effect aldosterone release

- when BP is too high, cells in the atria of the heart release ANP which INHIBITS aldosterone release

glucocorticoids effect

- increases metabolism of most cells

- maintains blood pressure

name a glucocorticoid hormone

cortisol

what are the effects of too much glucocorticoids

- inhibit inflammation by decreasing release of inflammatory chemicals

- depress immune system

what are cortisol actions during stress

- increase blood levels of glucose, fatty acids, and amino acids

- encourages cells to use fatty acids for fuels and save glucose for the brain

MAIN EFFECT is gluconeogenesis

what part of the nervous system is the adrenal medulla a part of

the autonomic nervous system

why do medullary chromatin cells synthesize

catecholamines:

- epinephrine and norepinephrine

effects of catecholamines

-vasoconstriction

-increased heart rate

-increased blood glucose levels

-blood diverted to brain, heart and skeletal muscle

T or F: the pineal gland receives indirect input from the visual pathways (retina) concerning intensity and duration of daylight

true

pinealocytes secrete...

melatonin

what does melatonin affect

- timing of sexual maturation

- day/night cycles

- physiological processes that shoe rhythmic variations (body temp, sleep, appetite)

glucagon (hyperglycemic) effect

raises blood glucose but targeting LIVER to break down glycogen

- synthesizes glucose from lactic acid and other noncarbohydrates

insulin (hypoglycemic) effect

lowers blood glucose levels

ovaries produce

estrogen and progestrone

estrogen effects

maturation of reproductive organs

- appearance of sexual characteristics

progesterone effects

causes breast development and cyclic changes to uterine mucosa

testes produce

testosterone

testosterone effects

- promotes the maturation of the male reproductive organs

- the development of secondary sex characteristics

- sperm production

T or F: the placenta is a temporary endocrine hormone that appears during pregnancy

true

adipose cells release

leptin: apetite control

resisting: insulin antagonist

adiponectin: enhances sensitivity to insulin

leptin

apetite control

resistin

insulin antagonist

adiponectin

enhances sensitivity to insulin

what are the 2 hormone secretions in the gastrointestinal tract

gastrin: stimulates release of HCl

cholecystokinin (CCK): activates pancreas and gallbladder

what hormones do the kidneys secrete

erythropoietin and renin