Cardiovascular Physiology and Pharmacology

Question 1

what is end diastolic volume

Answer 1

the volume in any chamber of the body after diastole

Question 2

describe cardiac cycle

Answer 2

0.8 of a second: 0.4 filling, 0.1 atria contract, 0.3 ventricle contract

Question 3

what is the cardiac output in a healthy individual

Answer 3

5L/min= 70b/min x 70mL/beat

Question 4

what is the pooling of fluid?

Answer 4

oedema

Question 5

what is cardiac output

Answer 5

amount of blood leaving the left ventricle per minute

Question 6

what pressures drive fluid exchange

Answer 6

osmotic pressure and blood pressure. when the blood pressure is higher than osmotic pressure fluid moves out of the capillary. when the blood pressure is lower than the osmotic pressure fluid moves into the capillary

Question 7

what are mechanisms to increase blood flow to certain areas. eg to skeletal muscle during exercise

Answer 7

closed system, vasoconstriction, pre-capillary sphincters

Question 8

what are mechanisms to increase blood flow to certain areas. eg to skeletal muscle during exercise

Answer 8

closed system, vasoconstriction, pre-capillary sphincters

Question 9

what are the metabolites for vasoconstriction and vasodilation respectively?

Answer 9

vasoconstrictors: endothelin, vasopressin, angiotensin II
vasodilators: nitric oxide, prostacyclin

Question 10

what are Korotkoff sounds, pulse pressure and mean arterial pressure

Answer 10

sounds of blood when it is turbulent flow, pulse pressure difference between systole and diastole, mean arterial pressure is around a third of the systolic pressure at any point in time

Question 11

what is blood pressure

Answer 11

blood exerted on the vessel walls

Question 12

what is heart failure

Answer 12

impairment of the pumping ability of the heart

Question 13

what happens in left and right heart failure

Answer 13

left heart failure: pulmonary oedma. right heart failure: oedma in the vena cava.

Question 14

Under what circumstances would the RAAS and sympathic nervous system do more harm than good, when blood pressure is low

Answer 14

When a person is suffering from heart failure, increasing blood pressure would increase the workload on an already failing heart.

Question 15

what are the two aims (one more common the the other) to treat heart failure

Answer 15

drugs commonly aim to decrease hypertension or less commonly, enhance ventricular contraction (positive inotropic agent)

Question 16

what is the mechanism of cardiac glycosides i.e. digoxin which comes from digitalis purpurea

Answer 16

Inhibit sodium/potassium ATPase pump which impairs the exchange between sodium and calcium, which elevates caclium and increases force of contraction

Question 17

What are the short term and long term mechanism for maintaining blood pressure?

Answer 17

Short term: Baroreceptor reflex to alter cardiac output and total peripheral resistance and Temporary fluid exchange between the interstitial fluid and plasma. Long term: kidney filtration and thirst mechanism.