Endocrine: 15.10: Adrenal Cortex Flashcards
What is Cushing syndrome?
excess cortisol
Pregnenolone is converted into _____ via 21-hydroxylase AND 11-hydroxylase.
cortisol
What is made in the zona reticularis?
sex steroids
What are the s/s of chronic adrenal insufficiency?
- lack of cortisol:
- hypotension
- increased ACTH –> hyperpigmentation (esp of oral mucosa)
- vomiting, diarrhea
- lack of aldosterone:
- hyponatremia
- hypovolemia
- hyperkalemia
The adrenal cortex secretes hormones derived from _____.
cholesterol
Why do pts with Cushings get HTN?
cortisol upregulates alpha-1 receptors on arterioles –> increased effects of NE
Pregnenolone is converted into cortisol via _____.
- 21-hydroxylase AND
- 11-hydroxylase
Pregnenolone is converted into ______ via 21-hydroxylase.
mineralocorticoids and cortisol
How does cortisol cause immunosuppression?
- inhibits phospholipase A2
- inhibits IL-2
- inhibits mast cell histamine release
What happens in Waterhouse-Friderichsen syndrome?
DIC –> bilateral necrosis of adrenal glands –> acute lack of cortisol –> massive hypotension
What is made in the zona fasciculata?
cortisol (glucocorticoids)
ACTH is derived from _____.
POMC
Name a mineralocorticoid.
Aldosterone
Cortisol ____ blood sugar by breaking down muscle.
increases
What are the lab findings in hyperaldosteronism?
- hypernatremia
- hypokalemia
- metabolic alkalosis
- HTN
Aldosterone causes ____ Na+ and _____ K+.
- increased Na+
- decreased K+
Pregnenolone is converted into cortisol via _____.
21-hydroxylase
How is Cushings diagnosed?
- increased 24 hour urinary cortisol
- high dose dexamethasone test
What happens if phospholipase A2 is inhibited?
no arachidonic acid metabolites form –> no inflammation
What is 17-hydroxylase important for?
pregnenolone conversion into cortisol and sex steroid hormones
Acute adrenal insuffienciency is usually caused by ______.
Waterhouse-Friderichsen syndrome
Why is cortisol essential for life?
it regulates blood vessel tone
In which hydroxylase deficiency is cortisol not produced?
ALL of them! (17, 11, 21)
What will the results of a high dose dexamethasone test be in Cushings from a pituitary adenoma?
suppression
What cancer loves to metastasize to the adrenals?
lung cancer
What will the results of a high dose dexamethasone test be in Cushings from an ectopic ACTH producing cancer?
failure of suppression
Why are abdominal striae seen in Cushings?
cortisol impairs collagen synthesis –> BVs rupture easily
What are the s/s of 21-hydroxylase deficiency in a female?
- clitoral enlargement
- hypotension
- bilateral adrenal hyperplasia
- hyponatremia
- hyperkalemia
- dehydration
Dx?
- adrenal gland looks like a sack of blood
Waterhouse-Friderichsen syndrome
Excess insulin causes _____ storage of fat.
increased
What bacteria causes Waterhouse-Friderichsen syndrome?
N. meningiditis
What happens when IL-2 is inhibited?
T-cells aren’t stimulated to grow
What are the s/s of 21-hydroxylase deficiency in a male?
- precocious puberty
- hypotension
- bilateral adrenal
- hyperplasia
- hyponatremia
- hyperkalemia
- dehydration
Name the 2 catecholamines.
- Epi
- NE
Pregnenolone is converted into mineralocorticoids via _____.
21-hydroxylase
Name the most common tumor to secrete ACTH.
small cell carcinoma of the lung
If there is a deficiency of 21-hydroxylase, there will be decreased _____ and increased _____.
- decreased mineralocorticoids and cortisol
- increased sex steroid hormones
