Newman HYHO Adrenal CIS Flashcards
Where does cortisol exert negative feedback?
1) hypothalamus (decrease release of CRH)
2) anterior pituitary (decrease release of ACTH)
What does HPA axis control?
reactions to stress (digestion, immune system, mood and emotions, sexuality, energy storage and expenditure)
Function of HPA axis negative feedback system
helps regulate the concentration of hormones in the blood and thus prevents over or under correction
Zones of adrenal cortex + hormone they produce
1) glomerulosa = mineralocorticoids
2) fasciculata = glucocorticoids
3) reticularis = sex steroids
Short term stress response in terms of HPA axis and adrenal cortex
stimulation of the adrenal medulla resulting in release of catecholamines ([nor]epinephrine)
Long term stress response in terms of HPA axis and adrenal cortex
- stimulation CRH stimulation of anterior pituitary
- stimulation of adrenal cortex by ACTH
- release of mineralocorticoids and glucocorticoids
Describe importance of RAAS and how angiotensin II stimulates secretion from adrenal cortex
1) RAAS is important for regulation of renal, cardiac, and vascular physiology
2) angiotensin II stimulates aldosterone secretion from the adrenal cortex
Most common cause of ambiguous genitalia in a genetically female infant
congenital adrenal hyperplasia (causing virilization of the genitalia)
Most common form of Congenital adrenal hyperplasia
21-hydroxylase deficiency (results in deficiency of aldosterone and cortisol, increase in testosterone)
signs and symptoms of CAH
- failure to thrive
- recurrent vomiting
- dehydration
- hypotension
- hyponatremia
- hyperkalemia
- shock
21-hydroxylase effects on aldosterone, cortisol, and androgens
- Aldosterone: low
- cortisol: low
- androgens: high
Mainstays of treatment in an infant in crisis d/t CAH
1) hydrocortisone (IV or IM)
2) fluids/glucose (IV)
3) management of hyperkalemia
Purpose of mandatory newborn screening
to detect potentially fatal or disabling conditions in newborns as early as possible, hopefully before they develop a serious illness
Three categories of adrenal gland defect responsible for primary adrenal insufficiency (Addison’s disease)
1) adrenal dysfunction
2) adrenal dysgenesis
3) impaired steroidogenesis
Signs and symptoms of primary adrenal insufficiency
- fatigue
- reduced stamina
- weakness
- anorexia
- weight loss
- skin hyperpigmentation
- salt craving
- musculoskeletal pain
lab findings seen with primary adrenal insufficiency
- moderate neutropenia
- low serum sodium
- high serum potassium
- fasting hypoglycemia
- low 8 am plasma cortisol accompanied by simultaneous significant elevation of plasma ACTH
laboratory findings seen in patients suffering from acute adrenal crisis
- low serum cortisol
- low blood sugar
- low serum sodium
- high serum potassium
- metabolic acidosis
- inadequate bump in cortisol level with ACTH stimulation test
Clinical signs acute adrenal crisus
- dehydration
- dizziness
- rapid heart rate
- rapid respiratory rate
- confusion
- abdominal pain
Main components of acute adrenal crisis treatment
- *hydrocortisone (critical and emergent if in crisis)
- fluids/glucose
- fludrocortisone (after the hydro is given)
- treat hyperkalemia
significance of low serum cortisol with low serum ACTH
secondary adrenal insufficiency
clinical signs and symptoms of cushing syndrome
- truncal obesity
- moon facies
- buffalo hump
- hirsutism
- thirst
- HTN
Abnormal labs/screening test associated with cushing syndrome
- *elevated midnight cortisol levels
- dexamethasone stimulation test
Explain dexamethasone suppression test findings associated with Cushing disease
ACTH: normal to mildly elevated
Cortisol: not suppressed by low doses, but suppressed by high doses
Explain dexamethasone suppression test findings associated with Primary hypercortisolism
ACTH: undetectable or low
cortisol: not suppressed by high or low doses
