Blood vessels

Question 1

cardiac output

Answer 1

blood pumped by LHS of heart into arteries

Question 2

total peripheral resistance

Answer 2

determined by arteries

Question 3

stroke volume

Answer 3

volume of blood expelled by LHS of heart to system arterial circulation

Question 4

cardiac afterload

Answer 4

determined by TPR against which the left ventricle works

resistance blood flow which the heart should overcome at each heart beat

Question 5

cardiac preload

Answer 5

venous return

i.e. amount of blood returned to right atria and ventricles

Question 6

contraction of blood vessels

Answer 6

agonist binds to GPCR (causing PIP2 to activate DAG and IP3)

IP3 mediated Ca2+ release from SR causing influx (= increase in [Ca2+] )

Ca2+ binds to calmodulin

phosphorylation via MLC kinase = contraction

Question 7

relaxation of blood vessels

Answer 7

reduction of agonist activated Ca2+ release = reduced influx

Dephosphorylation of MLC by MLC phosphatase

re-uptake by SERCA in SR (mitochondria helps this)

extrusion via NCX and Ca2+ - pump

Question 8

which conditions cause plasma levels to increase in patients?

Answer 8

hypercholesterolemia

atherosclerosis

hypertension

chronic renal failure

chronic heart failure

^ treated with ADMA

Question 9

ADMA

Answer 9

[competitive NOs inhibitor]

closely related to L-arginine

interferes with L-arginine in production of NO = key for endothelial function