Physio2 final pt 4(adrenal)

nibbs06's version from 2015-12-12 04:44


Question Answer
Mineralocorticoids are found in the (layer) Zona Glomerulosa of the cortex
Glucocorticoids are found in the (layer) Zona Fasciculata of the cortex
DHEA & Androsteindione are found in the (layer) Zona Reticularis of the cortex
Pregnenolone is made from cholesterol via (enzyme) Side Chain Cleavage Enzyme
What enzyme is exclusive to the zona glomerulosa? Aldosterone Synthase
Which enzyme isn't found in the Glomerulosa, but found in all the other layers? 17-a-Hydroxylase
What will be the outcome if a patient has a mutation in the enzyme that produces cortisol & aldosterone (21-a-Hydroxylase) Since cortisol regulates all of the hormones being released from the cortex, then if it's missing, it will not be able to feedback & inhibit the androgens (aldosterone is already not being produced), & in females this can cause masculinization.
Besides the androgens, the main regulator of the adrenal cortex hormones is ACTH
Which part of the hypothalamus secretes corticotrophin releasing hormone? Paraventricular Nucleus
What is the main feedback loop for ACTH regulation? Cortisol release goes to the Anterior Pituitary to inhibit ACTH release (Short-Loop)
POMC gets cleaved in the Anterior Pituitary
What is CEH regulated by & what does it do? ACTH binds and activates PKA, which will activate/phosphorylate CEH, located in a lipid droplet, to convert Cholesteryl-Esters into Cholesterol, converting it to Pregnenolone in the mitochondria in the presence of SCC
Cholesterol based hormones differ in release, compared to other hormones in that they are not stored nor are they in vesicles, they just get synthesized and leave
ACTH is released in a _________ fashion Pulsatile
Cortisol dumps glucose into the blood by (3 ways) Gluconeogenesis, increasing appetite and increasing lipolysis
What are the 2 main factors that stimulate aldosterone release? Plasma K+ levels & the Renin-Angiotensin-System (minor stimulation is ACTH)
What are the 3 effects of aldosterone? Decreases Na excretion, Decreases h2o excretion & it increases K+ excretion; (increase plasma [Na], causing h2o to follow & decrease [K] in the plasma)
The feedback to the adrenals for aldosterone is the decreasing [K+] in the plasma
What receptors do steroid hormones use & what's their function and uniqeness? Nuclear Receptors; they change the expression of downstream genes & all of the steroid-receptors work the same.
What's the importance of 11B-Hydroxysteroid Dehydrogenase-2? [Cortisol] is MUCH higher than [aldosterone] & it can bind to aldosterone-receptors. So in areas where aldosterone is absolutely required(kidney), 11B-HSD2 converts cortisol into cortisone(inactive)
Some adipose tissue expand & some contract, in the "remodeling effect" by cortisol, what's the likely reason? Different areas with different ratios of 11B-HSD-1 & 11B-HSD-2
Where are the catecholamines receptors located? Cell Surface
Epinephrine is almost exclusively released only from the Adrenal medulla
The difference between Epi & NorE on their target cells is that Epi is released by adrenal medually & its target cells are far way while NorE is released by Symp. Neuron AT the point of their target cells.
During hypoglycemia, what is released quickly and then inhibited quickly (quick rise & fall)? Epinephrine (some NorE)
The net effect of catecholamines on energy metabolism is similar to (2) Glucagon & Cortisol; dump glucose into the blood
Glycogenolysis in skeletal muscle occurs due to _________ & it will break it down into _________ & _________ Epinephrine breaks glycogen down into lactate & pyruvate, which go to the liver to become glucose
When epinephrine is released, what happens to insulin action and release? Insulin action & release is supressed in the presence of epinephrine
Epi's effects, geographically, are global & they re-adapt the body for emergency situations
Which adrenergic receptor is the only one to use PLC, instead of cAMP? alpha-1 adrenergic
Which adrenergic receptor is responsible for increasing arteriolar dilation(muscle)? Beta
Which adrenergic receptor is responsible for arteriolar vasoconstriction(splanchnic, renal, cutaneous & genital)? Alpha Adrenergic
Which adrenergic receptor does Epinephrine bind to more often? Beta
Which adrenergic receptor does Noepinephrine bind to more often? alpha
alpha-1 adrenergic receptor is responsible for smooth muscle contraction
In the ephinephrine signaling pathway, which molecule is credited to have a global effect on the body? PKA
What's the significance of measuring VMA or Metanephrine? Since Epi has a very short half-life, we cannot measure it, & instead we measure the break-down products (VMA & Metanephrine)
Primary adrenal insufficiency is defined as Primary Addison's, where not enough glucocorticoids are being secreted due to a problem in the adrenal cortex
Secondary adrenal insufficiency is defined as Secondary Addison's, where not enough ACTH is being produced, which causes insufficient release of cortisoll from the adrenals
Primary adrenal insufficiency is defined as Tertiary Addison's, where not enough CRH is being produced, which prevents the release of ACTH & ultimately preventing the release of cortisol
What are the 4 physiological consequences of adrenal insufficiency? Hypoglycemia, Hypotension, Hyperkalemia & Hyperpigmentation
Pheochromocytoma is The over production of catecholamines