control of BP- role of the kidney

Question 1

what is red blood cell mass altered by

Answer 1

erythropoietin

Question 2

what is plasma volume altered by

Answer 2

salt excretion by renin-angiotensin-aldosterone system (RASS)

antidiuretic hormone

atrial natriuretic peptide

Question 3

how is the state of the circulation (i.e. blood volume) communicated to the kidneys

Answer 3

hormones

pressure natriuesis

Question 4

what is the renin-angiotension-aldosterone system (RAAS)

Answer 4

this is a hormone system that regulates blood pressure, fluid, and electrolyte balance, systemic vascular resistance

Question 5

what is angiotension II and what does it do

Answer 5

main effector molecule of the RAS. It causes increases in blood pressure, influences renal tubuli to retain sodium and water, and stimulates aldosterone release from adrenal gland.

Question 6

angiotensin II production

Answer 6

Stimulated by secretion of renin

Renin is proteolytic

Stored in afferent arterioles of kidneys

Renin begins a cleavage cascade
→ Resulting in generation of angiotensin II

Question 7

what does angiotensin II stimulate

Answer 7

aldosterone from the adrenal cortex

Question 8

what does aldosterone stimulate

Answer 8

Na+ reabsorbtion

Question 9

which receptor does angiotensin II bind to

Answer 9

AT1 receptor on vascular cells. Stimulates contraction and therefore, vasoconstriction
contributes in total peripheral resistance

Question 10

renin secretion is caused by what

Answer 10

hypotension

Question 11

what is hypotension

Answer 11

→ Juxtaglomerular cells in arterioles inhibited by stretch
→ Fall in blood pressure causes release

Question 12

what does A fall in NaCl concentration activate

Answer 12

Activates cascade starting from macula densa

Question 13

go back and look at a summary of RAAS slide 14

Question 14

what does anti-diuretic hormone do

Answer 14

reduce volume, improves filtration

Question 15

what are choices of therapeutic interventions

Answer 15

→ Angiotensin-converting enzyme inhibitor (ACEi)
→ Angiotensin-II receptor blocker (ARB)

Question 16

what is angiotensin-converting enzyme inhibitor

Answer 16

first-line treatment in hypertension with type II diabetes
First line treatment in hypertension without type II diabetes but age <55 years and not of black african or african caribbean family origin

Question 17

summary

Answer 17

short-term control of blood pressure is facilitated via the baroreceptors
-aortic arch and carotid sinus

long-term control of blood pressure is facilitated via the kidneys
-RAAS
-3 FOLD OUTCOME
-Direct action on the hypothalamus-thirst and AVP
-direct action on the adrenal gland - aldosterone
-direct action on the kidney - renal hemodynamics