adrenal gland anatomy Flashcards
Adrenal cortex is derived from a ridge of __________ medulla (covered in a separate lecture) forms from ______ progenitors that migrate into the fetal cortex
Adrenal cortex is derived from a ridge of mesoderm, medulla (covered in a separate lecture) forms from neural progenitors that migrate into the fetal cortex
Cortex in fetus has only 2 zones–
definitive zone and provisional (“fetal”) zone
zone degenerates immediately after birth
Fetal zone
Definitive zone gradually develops into the 3 zones of the adult cortex–
glomerulosa, fasciculata, reticularis
is regulated by the renin angiotensin system while fasciculata and reticularis are is regulated by ACTH.
Zona glomerulosa
major developmental abn. is ________ can be found anywhere in retroperitoneum, near kidneys adrenals or gonads
ectopic adrenal
medulla or cortex?
Yellow and brown
Mesodermal origin
Granin-negative
cortex
medulla or cortex?
Gray
Neural origin
Restricted to mid-portion of normal gland
Granin-positive
medulla
aldosterone is produced in which zone?
zona glomerulosa
cortisol is produced in which zone?
Zona fasciculata
androgens is produced in which zone?
zona reticularis
catecholamines are produced in the?
adrenal medulla
cortisol effects on:
- liver
- skeletal muscle
- adipose tissue
- liver- stimulates gluconeogenesis
- skeletal muscle- inhibits lut-4 mediated glucose uptake
- adipose tissue - stimulates lipolysis, inhibits lipogenesis, inhibits GLUT-4 mediated glucose uptake
______ counteracts the effects of cortisol on proteolysis
Insulin
Effects of glucocorticoids on epinephine and glucagon, __________ blood pressure
increase
Mechanisms of glucocorticoid immune suppression
inhibit inflammatory cytokine production, T cell proliferation, promote T-cell apoptosis, inhibit leukocyte chemotaxis and prostaglanding production
primary adrenal defect such as addison’s disease will have pigmentation skin or not?
pigmented
secondary hypothalamus pituitary defect where ACTH is low will have pigmented skin or not?
non-pigmented
ELEVATED PLASMA K+
effects on zona glomerulosa
Depolarize glomerulosa cells and open Ca++ channels (enhances aldosterone synthesis)
ANP effect on zona glomerulosa
Produced by heart to work directly on glomerulosa cells to inhibit aldosterone synthesis
Target tissues for aldosterone are protected from glucocorticoid excess via the action of ______________________________, the enzyme that converts cortisol to cortisone, a biological inactive metabolite.
11b-hydroxysteroid dehydrogenase
Aldosterone is not a substrate for 11b-HSD and thus only it can bind to its receptor.
yep
Catecholamines ( epinephrine, norepinephrine) release regulated by
direct innervation
Release activated by stress, low blood pressure and volume, low glucose
Catecholamines are metabolized to metanephrines primarily by membrane-bound _______________epinephrine to metanephrine and norepinephrine to normetanephrine in chromaffin cells.
catecholamine-O-methyltransferase (COMT):
ACTH acts on the adrenal cortex through what second messenger systems?
cAMP
Aldosterone acts in the kidney to:
stimulate Na+ reabsorption
A patient complains of increased facial and abdominal fat, skeletal muscle weakness, and hypertension. The most likely cause of her symptoms is:
taking excess gluccorticoids for another medical problem
