Adrenal Cortex Flashcards
What are the three zones of the adrenal cortex?
Zona glomerulosa, zona fasciculata, zona reticularis
What do cells of the fasciculata and reticularis secrete?
Glucocorticoids and Sex hormones
Where is aldosterone produced?
Zona glomerulosa
Describe the pathogenesis of adrenal hyperplasia
Children are born with cortisol synthesis deficiency. ACTH is unopposed and upregulated causing adrenal hyperplasia.
What deficiency is a major cause of congenital adrenal hyperplasia?
21-Hydroxylase (P450C21) Deficiency
What is the function of 21-Hydroxylase? What occurs in its deficiency?
To convert 17-hydroxyprogesterone to 11-deoxycortisol; Impairment of cortisol synthesis and increased synthesis of androgens
What physical and sexual abnormalities are seen in a child with simple virilizing congenital adrenal hyperplasia?
Males: No abnormalities; Precocious puberty, potentially short stature Females Pseudohermaphroditism, fused labia, enlarged clitoris; Infertility
What is the cause of salt-wasting congenital adrenal hyperplasia?
Impaired aldosterone synthesis due to 21-hydroxylase deficiency
What does 11Beta-Hydroxylase Deficiency cause?
Congenital Adrenal Hyperplasia
What are three causes of adrenal cortical insufficiency?
Adrenal gland destruction, pituitary/hypothalamic dysfn or chronic corticosteroid therapy
What is another name for primary chronic adrenal insufficiency?
Addison Disease
What is the typical cause of Addison Disease?
Autoimmune destruction of the adrenal
What are the two types of polyglandular endocrinopathies?
Type I and Type II
What mutation is associated with Type I polyglandular disease?
AIRE gene (autoimmune regulator)
Another name for Type II polyglandular disease?
Schmidt Syndrome
What condition is associated with disorders in HLA-DR3?
Type II polyglandular autoimmune syndrome
A section shows an adrenal gland with crhonic inflammation and fibrosis in the cortex and an intact medulla. Dx?
Addison disease
What are characteristic signs of a person with primary adrenal insufficiency?
Hyperpigmentation and hypotension
What are the three major precipitating factors of acute adrenal crisis?
- Abrupt withdrawal of corticosteroid Tx
- Stressful precipitating factors such as infection or surgery
- Waterhouse-Friderichsen syndrome
What is the cause of secondary adrenal insufficiency?
Any condition that interferes with ACTH or CRH action
What are the two major syndromes seen in adrenal hyperfunction?
- Cushing syndrome (hypercortisolism)
- Conn Syndrome (hyperaldosteronism)
What is the difference betwixt Cushing syndrome and disease?
- Syndrome: Hypercortisolism from any cause
- Disease: Excess release of ACTH by corticotrope tumors
What is the most common cause of Cushing Sydrome in the US?
Chronic Corticosteroid Administration
What are the three major causes of ACTH-dependent adrenal hyperfunction?
- Ectopic ACTH production by a nonpituitary tumor
- Primary hypersecretion of ACTH by the pituitary (Cushing Disease)
- Inappropriate secretion of CRH by tumor
What type of cancer typically is responsible for ectopic ACTH production?
SCLC
What causes ACTH-independent Adrenal Hyperfunction?
Adrenal tumors
Clear lipid laden cells arranged in nests are shown. What is the Dx?
Adrenal Adenoma
Marked anisocytosis and nuclear pleomorphism is shown. What is the Dx?
Adrenal Cortical Carcinoma
In iatrogenic Cushing Syndrome, what Syx are absent that are typically seen in Cushing Syndrome?
Hypertension and Hirsutism
What are typical clinical features of Cushing syndrome?
- Obesity - Moon Face, Buffalo Hump, Trunkal and Abdominal obesity
- Atrophic skin, Purple Striae
- MSK - osteoporosis, muscle wasting
- HTN (due to mineralocorticoid excess)
- Female: Virilization, Facial Hair, Oligomenorrhea
- Men: ED, decreased libido
- Psychological disturbances
What causes glucose intolerance in cushing syndrome?
Cortisol -> Gluconeogenesis -> Glucose intolerance -> DIabetes Mellitus
What is increased in all forms of cushing syndrome?
Increased glucocorticoids
What causes inappropriate secretion of aldosterone?
Adrenal adenomas orhyperplasia
What does Conn Syndrome lead to?
Hypernatermia and Hypokalemia
What is type I familial hyperadlosteronism?
(Glucocorticoid suppressible) - caused by an autosomal dominant fusion of ACTH-responsive regulatory elements of the 11Beta Hydroxlase gene to the aldosterone synthase gene results in a hybrid gene that is ectopically and constitutively activated
What is type II familial hyperaldosteronism?
Adrenal cortical adenoma
