Lecture 7 Adrenal disorders Flashcards
Where is the adrenal glands located?
2in x 1inch triangle gland sitting atop each kidney
What are the layers of adrenal glands? (out to in)
Capsule
Cortex
Medulla
What are the zones of the cortex? (out to in)
Zona glomerules
Zona Fasciculata
Zona Reticularis
What is the purpose for the glomerulosa?
Secrete mineralcorticoids/aldosterone
What is the function of mineralcorticoids?
Regulate BP and electrolyte balance through RAAS
Na/water retention
K excretion
Increase BP and blood volume
What is the function of aldosterone?
Na/water retention
How does renin relate to aldosterone?
Renin is released from kidneys to help produce aldosterone
Its a negative feedback loop so…
Excess aldosterone causes a decrease of renin and vice versa
What is the function of the fasciculate?
Secretes glucocorticoids/cortisol
What is the function of glucocorticoids?
Gluconeogensis in liver(use/decrease protein stores)
Immune system suppression(decrease eosinophil, lymphocytes, and lymph tissue)
Decrease inflammation
When are glucocorticoids release?
Circadian rhythm
After meals
Response to endogenous/exogenous stressors
What kind of feedback is cortisol?
Negative feedback
What is the function of reticularis?
Secretes gonadocorticoids/DHEA
What is the goal of gonadocorticoids?
Converts sex steroids in gonads (development of sex characteristics)
What is the function of the medulla?
Secretes Epi/NoEpi
What is the medulla composed of?
Chromaffin cells
What is needed for steroid synthesis?
ACTH stimulation and cholesterol
What are the types of adrenal insufficiency?
Primary
Secondary
Tertiary
What is primal adrenal insufficiency?
Adrenal gland dysfunction
Decrease in cortisol/aldosterone
Addisons disease
What is 2ndary adrenal insufficiency?
Pituitary gland dysfunction
Decrease in ACTH, and cortisol
What is tertiary adrenal insufficiency?
Hypothalamic dysfunction
Decrease in CRH, ACTH, cortisol
What is Addison’s disease?
Destruction/dysfunction of adrenal cortex causing not enough glucocorticoids and mineralocorticoids being made
Usually an autoimmune dysfunction (80% of cases)
What specific enzymes does Addisons disease affect?
CYP21A2 (MC)
CYP11A1
CYP17
What are possible causes of Addisons decrease?
Autoimmune
Adrenoleukodystropy
Congenital adrenal insufficiency/hyperplasia(mutation or absence of cortex)
Infection (rare but usually from TB)
What is adrenaleukodystropy?
Genetic disorder
Accumulates long-chain FA in adrenal cortex inhibiting the effects of ACTH on adrenocortical cells
What drugs can cause chronic Addisons disease?
Ketoconazole (inhibits cortisol synthesis)
Phenytoin, barbiturates, rifampin(Increase metabolism of cortisol)
Mitotane(adrenocorticolytic drug, blocks steroid synthesis)
Glucocorticoids(suppress CRH/ACTH production)
What is used to treat adrenocortical carcinoma?
Mitotane
What can cause acute Addisons disease?
Adrenal hemorrhage
What can cause adrenal hemorrhage?
Sepsis
HIT
Anticoagulation
Antiphospholipid antibody syndrome
Trauma
Surgery
What is an adrenal “addisonian” crisis?
Emergent condition from insufficient cortisol
Caused by physical or emotional stressor in an Addison’s disease pt
Ex: infection, trauma, surgery, emotional turmoil
What are S/S of Chronic Addisons present?
S/S of glucocorticoid and mineralocorticoid deficiency
Onset is insidious and nonspecific
Skin and mucosal hyperpigmentation
Chronic: Vitiligo (from autoimmune destruction of dermal melanocytes, 10% of pts)
Anorexia, weight loss, fatigue, decrease stamina (first symptoms)
Why do pts with Addisons have hyperpigmentation?
ACTH binds to melanotic receptors
What are other general symptoms/presentations of chronic addisons?
Hypotension, dehydration, orthostatic lightheadedness
Hypoglycemia, weakness
Fevers, lymphoid tissue hyperplasia
Abdominal pain, N/V/D
Generalized pain
Change in axillary, public, body hair
Psychiatric
Neurologic
Amenorrhea