Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
The binding of alpha 1 receptors causes ___
|
Vascular and other smooth muscle contraction
|
|
The binding of beta 1 receptors causes ___
|
Positive inotropic and chronotropic effects on the heart
|
|
The binding of beta 2 receptors causes ___
|
Vascular, bronchial, and uterine smooth muscle relaxation
|
|
Symptoms associated w/ pheochromocytomas
|
• Hypertension
• Palpitations • Chest pain • Headaches • Sweating • Anxiety • Orthostatic hypotension |
|
The building block for all steroids produced by the adrenal cortex
What is the major source of cholesterol for the adrenal cortex? |
Cholesterol
80% is delivered by LDL’s |
|
Initial step of steroid hormone synthesis in the adrenal cortex
Where in the cell does this occur? Next step? Where does it occur? |
Cholesterol to pregnenolone via SCC enzyme (cholesterol desmolase)
Inner mitochondrial membrane Pregnenolone to progesterone Smooth ER |
|
Enzyme in the zona glomerulosa that helps convert progesterone to aldosterone
|
Aldosterone synthase
|
|
Enzyme in the zona fasciculate and zona reticularis that helps convert progesterone to cortisol and the androgens
|
17-hydroxylase
|
|
Two classic alpha antagonists
|
Phenoxybenzamine and phentalamine
|
|
Treatment for pheochromocytoma
|
Surgical removal and phenoxybenzamine administration
|
|
Major regulators of aldosterone secretion
|
Angiotensin II and plasma K+
|
|
How does hyperkalemia stimulate aldosterone secretion?
|
Depolarization of the membranes of the zona glomerulosa cells opens Ca++ channels, stimulating aldosterone production
|
|
How does cortisol increase blood glucose levels?
|
Decreases insulin sensitivity in muscle and adipose tissue, and stimulates gluconeogenesis
|
|
Actions and metabolic effects of cortisol
|
• Catabolism of proteins
• Increased lipolysis • Increased erythropoiesis • Increased bone resorption • Inhibited collagen formation • Increased GFR • Increased gastric acid and pepsin secretion • Decreased inflammatory response and cell-mediated immunity • Increased blood glucose |
|
Classification of endocrine disorders by the source of the disorder
|
• Primary: abnormal function of the gland itself
• Secondary: pituitary problem • Tertiary: hypothalamus |
|
The ability of a hormone to produce more than one action by binding to different receptors
|
Cross talk
|
|
Enzyme present on target cells for aldosterone that converts cortisol to a form which does not bind well to mineralocorticoid receptors
This blunts the mineralocorticoid action of cortisol |
11 beta-hydroxysteroid dehydrogenase type 2
|
|
Condition in which both cortisol and aldosterone are low
|
Addison’s disease
|
|
Major causes of hypoaldosteronism (3)
Major causes of hyperaldosteronism (2) |
• Autoimmune disease
• TB • Carcinoma of the adrenal cortex • Secreting tumor of the adrenal cortex • Excess rennin secretion |
|
Excessive production of aldosterone caused by a tumor in the adrenal cortex
Also referred to as primary hyperaldosteronism |
Conn’s syndrome
|
|
Autoimmune distruction of the adrenal cortex
Also referred to as primary adrenocortical insufficiency |
Addison’s disease
|
|
Common signs/symptoms of Addison’s disease
|
• Weakness, fatigue, weight loss
• Hyperpigmentation, elevated ACTH • Hyperkalemia, hyponatremia, hypertension • Hypoglycemia • GI problems |
|
Congenital condition in which excessive adrenal androgens are producedand secreted due to lack of functioning 21-hydroxylase enzyme
What is the therapy? |
Adrenogenital syndrome
Administration of cortisol |
|
The rate limiting step in the synthesis of catecholamines
|
The first step, tyrosine to DOPA
|
|
Last step in the synthesis of catecholamines
What hormone induces the enzyme that catalyzes this step? |
NE to E via phenylethanolamine N-methyltransferase (PNMT)
Cortisol |
|
2 enzymes that break down catecholamines
|
COMT and MAO
|
|
What are the products when catecholamines are O-methylated by COMT?
What product is formed when COMT and MAO act on each other’s products in the breakdown of catecholamines? |
Metanephrine and normetanephrine
Vanillymandelic acid (VMA) |