Cardiovascular System

Question 1

which circulation usually has more resistance, pulmonary or arterial

Answer 1

arterial circulation

Question 2

Normal MAP?

Answer 2

70-100

Question 3

the low resistance in the pulmonary circuit means what for the arterial and vensus pressures in there

Answer 3

only a small difference is needed between the two to maintain blood flow

Question 4

most coronary venous bloods drains into where

Answer 4

coronary sinus by the right atrium

Question 5

the right and left coronary arteries that supply blood to the heart arise from where

Answer 5

aortic root

Question 6

what part of the heart is the most susceptible to ischemia and why

Answer 6

the Subendocardium, because contraction force is the highest near the endocardium, compressing the coronary vessels to supply the heart with blood

Question 7

why is cardiac venous blood the most deoxygenated then any other tissue

Answer 7

because the myocardium extracts 60-75% of the o2 in blood that comes too it

Question 8

increased 02 to the heart can only be achieved how

Answer 8

by increasing coronary blood flow

Question 9

what are the two most important factors in in coronary blood flow autoreguliton

Answer 9

Adenosine and Nitrix Oxide

Question 10

Adenosine is a product of?

Answer 10

ATP

Question 11

what is the major regulator of flow-mediated vasodilation in large arteries and pre-arteriolar vessels

Answer 11

Nitric Oxide

Question 12

What works within vascular smooth muscles via soluble guanylate cyclase enzyme to increase proaction of cGMP and cause smooth muscle relaxation

Answer 12

Nitric Oxide

Question 13

B1 receptors cause?

Answer 13

Heart excitation

Question 14

B2 receptors cause?

Answer 14

vasodialtion

Question 15

what is a powerful vasoconstrictor that regulates systemic blood pressure

Answer 15

Angiotensin II

Question 16

what is Nitric Oxide synthesized from

Answer 16

Arginine and O2 in the endothelial cells

Question 17

Hypotension, elevated JVP, and muffled heart sounds are known as the Beck Triad and indicate what

Answer 17

cardiac tamponade

Question 18

Late diastolic collapse of the right atrium and pericardial fluid accumulation is seen in

Answer 18

cardiac tamponade (due to fluid displacement when the ventricles expand)

Question 19

what is the exaggerated drop is systolic BP (>10) during inspiration called

Answer 19

plusus paradoxus

Question 20

Plusus Paradoxes can occur in what 5 pathologies?

Answer 20

cardiac tamponade
hypovolemic shock
asthma
COPD
constrictive pericarditis

Question 21

voltage gated L-type Calcium channels with a large influx of Ca2+ into the cell open at what phase in the cardiac cycle

Answer 21

Phase 0: depolarization

Question 22

closure of L-type Calcium channels and the opening of K+ channel is seen in which phase of the cardiac cycle

Answer 22

Phase 3: repolarization

Question 23

slow influx of sodium beginning at the end of depolarizations happens in what phase of the cardiac cycle

Answer 23

Phase 4: pacemaker potential

Question 24

how does adenosine slow down phase 4

Answer 24

it acts on the A1 receptors on the cardiac cells and activates potassium channels causing the membrane potential to remain negative for longer periods of time

also inhibits L-type calcium channels

Question 25

what is useful to give for paroxysmal supra ventricular tachycardia

Answer 25

adenosine

Question 26

what is the abrupt cessation of organized cardiac activity causing an inability to maintain adequate tissue perfusion

Answer 26

Suden Cardiac Death SCD

Question 27

what is the most frequent mechanism of SCD in the first 48 hours after and acute MI and is related to electrical instability due to lack of perfusion to the ischemic myocardium

Answer 27

Ventricular Fibrillation

Question 28

occlusion of the LAD most commonly present with what

Answer 28

ventricular septal rupture

Question 29

what two things reduce the rate of phase 4

Answer 29

Adenosine and Ach

Question 30

what type of calcium channels are opened in phase 4

Answer 30

t-type