Pathoma Review Flashcards
Cushing Disease at it’s most basic is
Excess Cortisol
What are the Clinical FIndings of Cushings disease and how do they relate to the physiology of Cortisol
- Muscle Weakness: Cortisol breaks down proteins to be used in gluconeogenesis. Remember, it is catabolic and its main goal is to keep glucose in the blood to keep you alive. It will do anything to make sure this happens.
- Moon Fascies, Buffalo Hump, Truncal Obesity: This is due to the relocation of fat. As blood glucose increases, so does insulin. Insulin increases fat storage
- Abdominal Striae: Cortisol inhibits Collagen synthesis, you get thin skin
- Hypertension: Cortisol has a direct effect on vasoconstriction by upregulating Alpha 2 receptors
- Osteoporosis
- Inmmune suppression: Three methods 1) Inhibit phospholipase A2 which means you get no arachidonic acid metabolites which make prostaglandin 2) Inhibit IL-2 3) Inhibit Histamine Release
MMAHOI
Causes of Cushings
1) corticosteroids: These basically are cortisol. ACTH will be low, therefore both adrenals will hypertrophy
2) Adrenal adenoma, carcinoma or hyperplasia: ACTH will be low. Uninvolved gland will atrophy
3) Pituitary adenoma: ACTH will be high. HIGH DOSE DEXAMETHASONE WILL SUPPRESS IT.
4) Paraneoplastic ACTH secretion
HIGH DOSE DEX WON”T TOUCH IT
Hyperaldosteronism presentation
Hypernatremia (actually it is usually normal because the ADH increases water reabsorption so sodium concentration doesn’t get too far out of whack)
Hypokalemia
Metabolic acidosis_ loss of H
Will also see hypertension due to plasma volume increase
Primary hyperaldosteronism will have LOW RENIN
Usually caused by adrenal adenoma
Secondary hyperaldosteronism will show HIGH RENIN
This is most likely due to volume loss or CHF
Congenital adrenal hyperplasia
EXCESS SEX steroids
Most common cause of congenital adrenal hyperplasia is:
deficiency in 21-hydroxylase. This is the enzyme needed to convert Pregnenolone to Mineralocorticoid and Glucocorticoid. WHen its gone, everything is shunted into sex steroids
Why do you get congenital adrenal hyperplasia?
Because without cortisol being made, ACTH secretion skyrockets and we know that whenever ACTH touches the Adrenals, they grow.
Clinical features of congenital adrenal hyperplasia?
- Lack of ADH = no salt, high k, hypotension
- Life threatening hypotension due to lack of cortisol
- Precocious puberty in males, clitoral enlargement in females.
Acute lack of adrenal hormones
Waterhouse Friedrichsen syndrome
What happens in WFS?
Necrosis of the adrenal glands due to DIC.
What causes WFS?
N. Meningitidis usually
What is the cause of death in WFS
Hypotension—-NO CORTISOL
What is Addison’s disease
Chronic insufficiency of the Adrenal glands
Most common cause of Addison’s in the US
Autoimmune