Adrenocortical Hormones Flashcards
1
Q
Adrenal gland zones
A
- zona glomerulosa: contains aldosterone synthase enzyme –> makes aldosteron
- zona fasiculata: makes cortisol and corticosteroids under control of ACTH from pituitary
- zona reticularis: makes DHEA and androstenedione (also controlled by ACTH)
- out to in = mineralocorticoids, glucocorticoids, androgens
2
Q
mineralocorticoids
A
- effect of absence demonstrates function
- if you don’t have aldosterone, ECF decreases, Na+ decreases
3
Q
general function of adrenal glands
A
- corticosteroids are derived from cholesterol
- cholesterol enters the cell, is delivered to mitochondria where it is cleaved by cholesterol desmolase
- the production of corticosteroids can occur in either the mitochondria or the endoplasmic reticulum
4
Q
glucocorticoids
A
- preference for cortisol (95% glucocorticoid activity)
- inflammation effect (prevents release of lysosomal contents, decreases pain 00> in the heat of battle we have cort, stress hormone that suppresses pain and inflammatory fn)
5
Q
CAH
A
- congenital adrenal hyperplasia (aka adrenogenital syndrome)
- deficiency of cortisol production
- results in INCREASED ACTH and adrenal hyperplasia
- adrenal androgens and mineralocorticoids may be produced in excess
- this is often missed in males at birth unless genital hyperplasia is present, occasional adrenal crisis with salt wasting is present
- females experience virilization syndrome due to androgen excess (enlarged clitoris, fused labia, urogenital sinus)
6
Q
tx of CAH
A
- corticosteroid replacement
- fludricortisone acetate to salt wasters
- female reconstructive surgery may be necessary if malformation is severe
7
Q
adrenocortical insufficiency
A
- primary = addison’s dz due to adrenal destruction (adrenal deficiency dz)
- secondary = due to disorder of the hypothalamo-pituitary-adrenal axis
8
Q
Addison’s dizease
A
- adrenocortical hormones DECREASE and ACTH INCREASES
- destruction involves all layers of the adrenal glands - autoimmune destruction
- often caused by TB, rarely by cancer matastasis, fungus, CMV< amyloid, homochromatosis
- bilateral hemorrhage possible on anticoagulation tx, open heart sx, birth trauma
- JFK had addison’s - he was probably also overmedicated
9
Q
addison’s s/sx
A
- loss of Na, Cl, water, increase K
- orthostatics, dehydration, weakness, fatigue
- cardiovascular collapse and shock possible
- poor stress tolerance
- hypoglycemia, lethargy, fever, GI, sx
- hyperpigmentation from elevated ACTH, “bronzing” or tanned appearance due to sequence homology with MSH
- gums and oral mucosa may be blue-black
- hydrocortisone alone or in combo with fludrocortisone for tx
10
Q
secondary adrenal insufficiency
A
- hypopituitarism
- rapid withdrawal of glucocorticoids administered clinically
- putting someone on steroids: asthma, back pain, etc.
- increased steroid –> decreased ACTH and decreased function of adrenal gland –> if you take it away too fast, can cause adrenal crisis
11
Q
cushing’s syndrome
A
- any cause
- excess ACTH from pituitary = cushings dz
- adrenal tumor
- non-pituitary, ACTH secreting tumor
12
Q
cushings s/sx
A
- exaggeration of cortisol effects
- altered fat metabolism (buffalo hump, moon fascies)l
- muscle weakness
- thin extremities
- thin, parchment skin
- purple striae
- osteoporosis
- glucose metabolism: 20% have DM, mineralocorticoid effects (low K, high Na, HTN)
- infections
- gastric ulcers
- hirsutism, acne, menstrual irrecularity
13
Q
dx of cushings
A
- 24 hr cort from urine
- loss of diurnal pattern of secretions, elevated late night levels
- dex suppression test
- plasma ACTH
14
Q
what does adrenal cortex secrete
A
CORTICOSTEROIDS!
-mineralocorticoids, glucocorticoids, sex hormones
15
Q
what does cortisol do?
A
- decreases protein stores
- increase blood glucose concentration
- mobilizes fatty acids from adipose tissue
- decrease inflammatory response
- suppress immune system
