The vasculature

Question 1

what causes vasoconstriction

Answer 1

alpha 1 stimulation by NA has greatest vasoconstriction effect

Question 2

what Ca channel blockers would be given to lower BP

Answer 2

verapamil

amlodipine

Question 3

what drug classes are used to affect the vasculature (and therefore BP)

Answer 3

ACEI
calcium channel blocker
angiotensin receptor blockers
alpha adrenoceptor blockers

Question 4

what BP value defines hypertension

Answer 4

140/90mmHg

Question 5

what are the side effects of ACEIs

Answer 5

Cough
hypotension
fetal injury
renal failure
hyperkalaemia

Question 6

what are the side effects of angiotensin receptor blockers

Answer 6

*hypotension*
angioedema
hyperkalaemia
fetal injury
renal failure

Question 7

what are the side effects of Ca channel blockers

Answer 7

reflex tachycardia

increased inotropy

Question 8

what are the side effects of alpha adrenoceptor antagonists

Answer 8

not able to vasoconstrict -> orthostatic hypotension, dizziness etc

Question 9

what are the 3 factors in Virchow’s triad

Answer 9

rate of blood flow
consistency of blood
blood vessel wall integrity

Question 10

what is the pathogenesis of atherosclerosis

Answer 10

endothelial damage
protective response producing cellular adhesion molecules
monocyte and T-lymphocytes attach to sticky endothelial cells
they migrate through arterial wall to sub- endothelial space
macrophage uptake of oxidised LDL-cholesterol
formation of lipid-rich foam cells
fatty streak and plaque formation

Question 11

what classes of drugs (3) are used to prevent and treat atherosclerosis

Answer 11

statins
bile acid sequestrants
nicotinic acid

Question 12

how do stains work

Answer 12

they inhibit the HMG-CoA reductase enzyme
this is the enzyme in the rate-limiting step of cholesterol formation
this leads to hepatocytes up-regulating LDL receptors which removes more LDL

(rule of 6)

Question 13

how are lipoproteins metabolised

Answer 13

fat is transported to liver in chylomicrons and taken up via LDL receptors
surplus fat is released into blood as VLDL (these can be taken back into liver or hydrolysed by lipoprotein lipase into LDL)
LDL delivers cholesterol to rest of body
amount of LDL in blood is regulated by about of LDL receptors on liver

Question 14

what are the stages of coagulation

Answer 14

initiation
amplification
propagation

Question 15

what happens during coagulation initiation

Answer 15

tissue factor activates factor X and V which causes formation of prothrombinase complex
prothrombinase complex activates fII (prothrombin) to create fica (thrombin)

antithrombin (AT-III) inactivates fIIa and fXa

Question 16

what happens during coagulation amplification

Answer 16

factor IIa (thrombin) binds to protease-activating receptor (PAR) on platelets makes them change shape and become activated
PAR causes increase in intracellular Ca2+ which causes exocytosis of ADP from dense granules
ADP activates P2Y12 receptors -> activation/aggregation 
ADP liberates arachidonic acid which is turned into thromboxane A2 by COX. TXA2 activation leads to increased GPIIb/IIIa integrin receptors on platelet surface  -> activation/aggregation

Question 17

what is the role of vitamin K in coagulation

Answer 17

generates factor II, VII, IX, X

Question 18

what happens during coagulation propagation

Answer 18

factor IIa converts fibrinogen to fibrin