Endocrinology: Adrenal Glands Flashcards
zona glomerulosa makes what hormone
mineralcorticoids
**aldosterone
constitues about 15% of cortex
zona fasciculata makes what hormone
glucocoticoids
*cortisol
constitues about 78% of cortex
Zona Reticularis makes what hormone
*estrogens/Androgens—DHEA and androstenedione
constitues about 7% of cortex
what does Chromaffin cells produce
catecholamines
*epi and norepi
where are the catecholamines produced
medulla
effects of glucocorticoids
- anti-inflammatory
- metabolic–CHO
- neurologic
- growth suppressing
glucocorticoids stimulate what in liver ?
gluconeogenesis in liver
how does glucocortiods promote gluconeogenesis
via decreasing uptake of glucose into muscle cells, adipose cells and lymphatic cells
glucocorticoids effect on immunity?
innate and adaptive immunity
AKA some SE when tx with glucocorticoids:
*poor wound infection
*incr risk of infections
GLucocorticoids effect on proteins?
- stimulate catabolism
* **breakdown protein in the body
glucorticoids effect on AAs?
inhibit amino acid uptake and protein
glucocorticoids effect on bone?
inhibit bone formation
glucocorticoids effect on ADH secrtion
inhibit it
Glucocorticoids effect on gastric acids?
stimulate gastric acid secretion
most superficial layer of adrenal cortex?
Zona Glomerulosa
*just under the capsule
what enzyme does the zona glomerulosa cells have
aldosterone synthase
secretion of aldosterone is controllled by?
ECF [ ] of angiotensin II and K+
1. RAAS system
mineralcorticoid action
regrulates ECF fluid volume
- stimulates reabsoprtion of NA in kidneys AKA Na+ retention**
- stimulates secretion of K+ and H+ in kidneys
how does aldosterone cause NA retention?
by increasing the acts of the sodium pumps in nephrons
what stimulates RAAS? (3)
- Hyperkalemia
- hyponatremia and water depletion
- hypotension or decr blood volume–sepsis, hemm
middle layer of the adrenal cortex
zona fasiculata
*secretes cortisol
release of ACTH stim by? (4)
which is inhibitory and which is stimulatory
- CRH–stimulatory
- free cortisol–inhibitory
- stress–stimulatory
- sleep-wake cycle–circadian rhythm
deepest layer of adrenal cortex
zona Reticularis
*adrenal adrogens
sexual characterisitcs are determiend by?
gonadal testosterone
what supresses androgens
exogenous glucocorticoids
cells found in the adrenal medulla?
Chromaffin cells—pheochromocytes
function of chromaffin cells
storage of catecholamines–epi and norepi
epi and norepi synthesizes from which AA?
AA–phenylalanin
only ___% of the circulating epi is secreted from adrenal medulla
-where does the rest come from?
30%
*rest comes from nerve terminals in sympNS–secreted when body need it
when do chromaffin cells release catecholamines
- stress
- trauma
- physiological stress: hypoclygemia, hypoxia, hypovolemia,
which hormones of the adrenal cortex are protein bound
cortisol
androgens
ACTH produced in?
AP
which hormone stimulates ACTH
Cortiotropin rel hormone in hypothalm
which part of adrenal gland has high vasculature
adrenal medulla–so catecholamines get into blood right away
which nerve innervates adrenal gland
splanchnic nerve
which cells in kidneys stimulate renin
juxtaglomerular cells
what there is decreased perfusion…. what happens (in kidneys(
JG cells stimulate kidneys to stimulate renin
function of renin
renin converts angiotensinogen–>angiotensin I—>converted to angiotensin II via ACE
where is angiotensinogen found
liver
where is ACE found
lung capillaries
angiotensin II is a potent?
vasocontrictor—incrs BP
Angiotensin II stimulates____
Aldosterone from adrenal cortex
aldosterones action on kidney tubules
- increases reabsoprtion of NA
- increases excretion of K+ and H+ via tubules
- incrs water retention–incrs blood volume–incrs BP
- prevents acidosis via secretion of H+
ADH comes frOM? and is responsible for?
vs
Aldosterone comes from? and resp for?
which is a secondary and primary cause of fluid overload?
ADH—-post pit…resp for reabsorption of h20–causing water retention
aldosterone— adrenal cortex— resp for h20 and NA reabsoprtion— causing water retention–
***fluid overload
ADH=secondary cause
Aldosterone=primary cause
angiotensin II stimulates release of ___ (2)
ADH or vasopresin
&
Aldosterone
who is in charge of long term BP regulation
aldosterone
ADH/vasopressin
what is a main SE of longterm use of exogenous glucocorticoids?
osteoporosis—bc glucocorticoids inhibit bone formation
WBC count rises/lowers when on glucocortioids
WHY???
INCREASES
*glucos inhbit bone formation–osteoporosis–bone b/d releases immune cells— increases LEUKOCYTES
less of cortisol are HIGH/LOW in am?
high
explain anti-inflammatpry funct of cortisol
inhibits WBC leukocytes–decreases the immune responses and can delay healing of damaged tissue
the release of cortisol is____?
pulsatile
AND
circadian
what does pulsatile relese of cortisol mean
its rel in spurts— >7 times throughout the day
which receptor in the adrenal gland does ACTH bind to
melanocortin-2 receptor
where is aldosterone metabolized and excreted
liver
urine
what controls release of androgens
ACTH
which is the most abundant circulating hormone in the body?
DHEA
major function of testosterone
masculinization and libido
in women, androgens are converted to?
estrogen and progesterone
in post menopausal women, where is the main supply of endogenous estrogen?
adrenal cortex
low levels of DHEA are assoc with what diseases in mn and women
cardiovasc in men
premenopausal BC and OC in women
high levels of DHEA can put a women at risk for?
postmenopasual BC
what is increased aldosterone secretion called
decreaad?
hyPERaldosternonism
HYPOaldosteronism
Increasd cortisol secretion leads to?
Cushing’s syndrome
what is decreased cortisol secretion called
adrenal insufficiency
Conn syndrome can cause?
hypernatremia
hyPOkalemia
HTN
MCC of primary hyperaldosteronism?
bilateral adrenal hyperplasia
conn sydrome is a type of?
primary hyperaldosteronism
MCC of secondary hyperaldosteronism?
renal artery stenosis
primary hyperaldosteronism is a cause of ____
secondary HTN
what do we suspect in PTs <30 or >60 who develop sudden HTN
primary hyperaldosteronism
what do we suspect with PTs who have uncontrolled HTN after trying 3 different BP meds?
primary hyperaldosteronism
addison’s disease is?
MCC?
when over 90% of adrenal tissue is destroyed
*MC cause–> autoimmune destruction
primary hypoaldosteronism MC caused by?
addison’s disease–>adrenal insufficiency
