Endocrinology II

Question 1

The water concentration of the body is monitored by

Answer 1

osmoreceptors in the hypothalamus, which
detect the concentration of electrolytes in the extracellular fluid.

Question 2

polypeptide hormone ADH/vasopressin is produced and released where

Answer 2

The hypothalamus produces it,
then its transported to and released from the posterior pituitary

Question 3

The principal action of ADH is

Answer 3

to regulate the amount of water excreted by the kidneys by causing direct water reabsorption from the kidney
tubules

Question 4

ADH mechanism of action more specifically

Answer 4

travels via the bloodstream to the kidneys where it temporarily inserts aquaporins into the kidney tubules thus kidneys become more permeable to water

Question 5

what results in diabetes insipidus

Answer 5

Chronic underproduction of ADH or a mutation in the ADH receptor

Question 6

Define diabetes insipidus

Answer 6

a rare condition where you produce a large amount of urine and often feel thirsty

Question 7

Another hormone responsible for maintaining electrolyte concentrations

Answer 7

aldosterone, a steroid hormone produced by the adrenal cortex

Question 8

how does aldosterone aid in maintaining proper water balance

Answer 8

by enhancing Na+ reabsorption and K+ secretion from in kidney tubules.

The reabsorption of Na+ also results in the osmotic reabsorption of water, which alters blood volume and blood pressure.

Question 9

what type of corticosteroid is aldosterone

Answer 9

referred to as a mineralocorticoid, which is a
corticosteroid that affects ion and water balance.

Question 10

Aldosterone release is stimulated by

Answer 10

a decrease in blood sodium levels,
blood volume, or blood pressure,
or an increase in blood potassium levels.

Question 11

what is RAAS

Answer 11

renin-angiotensin-aldosterone system

Question 12

when is RAAS activated

Answer 12

When blood pressure drops

Question 13

Where is renin produced and released

Answer 13

in the cells of the juxtaglomerular apparatus,
which regulates the functions of the nephrons of
the kidney

Question 14

What is renin and what does it do

Answer 14

an enzyme, circulates in the blood, reacts with a
plasma protein produced by the liver called angiotensinogen

Question 15

how is angiotensin I made

Answer 15

When angiotensinogen is cleaved by renin, it produces angiotensin I

Question 16

what is angiotensin II and what does it do

Answer 16

functions as a hormone, causing the release of aldosterone by the adrenal cortex,
resulting in increased Na+ reabsorption, water retention, and an increase in blood pressure.

Question 17

in addition to affecting aldosterone, what else does angiotensin II stimulate

Answer 17

in addition to being a potent vasoconstrictor, also causes an increase in ADH and increased thirst, both of which help to raise blood pressure.

Question 18

what is a natriuretic peptide

Answer 18

circulating peptide hormones of cardiac origin that induce natriuresis, which is the excretion of sodium by the kidneys.

important in the regulation of intravascular blood volume and vascular tone.

Question 19

what is ANP and where secreted

Answer 19

Atrial natriuretic peptide is secreted by atrial cardiac muscle cells

Question 20

what is BNP and where secreted

Answer 20

Brain natriuretic peptide is secreted by ventricular cardiac muscle cells

Question 21

name some natriuretic peptide functions

Answer 21

increase urinary excretion of sodium,
increase GFR,
inhibit Na+ reabsorption in distal tubule and collecting duct,
inhibit secretion of renin, aldosterone and vasopressin, decrease cardiac output,
inhibit sympathetic activity

Question 22

insulin mechanism of action for lowering plasma GLU concentration

Answer 22

insulin binds to its target cell via insulin receptors,
signal transduction triggers
the cell to incorporate glucose transport proteins into its membrane.
This allows glucose to enter the cell, where it can be used as an energy source.

Question 23

insulin mechanism of action for lowering plasma GLU concentration

Answer 23

insulin binds to its target cell via insulin receptors,
signal transduction triggers
the cell to incorporate glucose transport proteins into its membrane.
This allows glucose to enter the cells and plasma concent. lowers

Question 24

diabetes mellitus can be specifically due to what 2 processes

Answer 24

inadequate levels of insulin production by the beta cells of the pancreas,
or by reduced sensitivity of tissue cells to insulin.

Question 25

calcitonin is from?

Answer 25

the parafollicular or C cells in the thyroid gland