Coronary circulation II + Venous return

Question 1

Small cardiac veins return blood FROM

Answer 1

Right ventricular muscle

Question 2

Thebesian veins EMPTY in

Answer 2

All chambers

Question 3

Venous return =

Answer 3

(Venous P - Right Atrium P) / Venous Resistance

Question 4

Increased vasoconstriction will lead to (Higher or lower VR)

Answer 4

Lower venous return due to a higher resistance

Question 5

If there is constriction due to SYMPATHETIC ACTIVATION (ex. sports) there will be an increase or decrease of VR

Answer 5

Increased venous return from Increased RESISTANCE –> Increased V PRESSURE pressure –> Increased venous RETURN

Question 6

Blood flows from high to low pressure?

Answer 6

Yes

Question 7

When do valves open

Answer 7

When pressure in 1st chamber > pressure in 2nd

Question 8

Contraction causes increased pressure within a chamber?

Answer 8

Yes

Question 9

PHASE 1 CC corresponds to

Answer 9

Atrial depolarization

Question 10

PHASE 1, systole or diastole

Answer 10

Diastole, muscle relaxation

Question 11

PHASE 1 (CC): Why does ventricular volume slightly increase if we are in diastole

Answer 11

Because there is passive flow from atria to ventricle before contraction

Question 12

Increase in Atrial Pressure causes

Answer 12

Atrial contraction

Question 13

Pa > Pv causes in valves

Answer 13

To open (both tricuspid and mitral)

Question 14

Pa < Pv causes in valves

Answer 14

To close (both tricuspid and mitral)

Question 15

1ST SOUND WHEN

Answer 15

Atrioventricular valves CLOSE (tricuspid + mitral)

Question 16

When does systole begin

Answer 16

At the end of the 1ST sound, when the tricuspid and mitral valve close

Question 17

PHASE 2 CC corresponds to

Answer 17

Isovolumetric contraction (systole)

Question 18

What causes the beginning of ventricular contraction

Answer 18

Increase of ventricular pressure

Question 19

Why do semilunar valves not open in PHASE 2

Answer 19

Because aortic and pulmonary artery P > Ventricular P

Question 20

Why is Phase 2 called an ISOVOLUMETRIC CONTRACTION

Answer 20

Because ventricle begins to contract in a closed space since semilunar valves are not yet opened

Question 21

When will ventricular ejection occur

Answer 21

When P ventricle > P aorta + P pulmonary artery

Question 22

Valves OPEN when

Answer 22

P in 1st chamber > P 2nd chamber

Question 23

Valves CLOSE when

Answer 23

P in 1st chamber < P 2nd chamber

Question 24

PHASE 3 CC corresponds to

Answer 24

Rapid ejection (systole, muscle contraction)

Question 25

Aortic and pulmonary valves open because

Answer 25

P ventricle >> P aorta + P pulmonary artery

Question 26

Peak P of aorta occurs at

Answer 26

PHASE 3: Rapid ejection

Question 27

In which phase is the max. blood ejection

Answer 27

At rapid ejection (systole)

Question 28

PHASE 4 CC corresponds to

Answer 28

Reduced ejection

Question 29

T wave corresponds to

Answer 29

Ventricular repolarization

Question 30

T wave of EKG is in which phase of CC

Answer 30

Reduced ejection

Question 31

Why is force ejection reduced at this phase?

Answer 31

Because ventricular pressure decreases as ventricular volume decreases

Question 32

Why do semilunar valves close at PHASE 4 of reduced ejection

Answer 32

Because P aorta + P pulmonary artery > P ventricles

Question 33

Where is the end of SYSTOLE and beginning of 2nd diastole

Answer 33

When semilunar valves close, end of ventricular ejection

Question 34

2ND SOUND WHEN

Answer 34

Semilunar valves close

Question 35

PHASE 5 corresponds to

Answer 35

Isovolumetric relaxation (diastole)

Question 36

Why do ventricles relax in isovolumetric relaxation

Answer 36

Because P ventricular decreases and valves are closed

Question 37

Why is it called isovolumetric relaxation

Answer 37

Because volume remains unchanged

Question 38

Why is P atrial slowly increasing during isovolumetric relaxation

Answer 38

Because atria are being filled with blood

Question 39

PHASE 6 corresponds to

Answer 39

Ventricular filling

Question 40

When does ventricular filling start

Answer 40

When P atria > P ventricle so atrioventricular valves open

Question 41

Why is there ventricular filling before atrial contraction during Ventricular filling phase

Answer 41

Because there is passive flow of blood to ventricle before the atria contracts. --> Phase 1

Question 42

Which is the longest phase of the cycle

Answer 42

Slow ventricular filling

Question 43

Difference between phase 6 and 7 in CC

Answer 43

Phase 6 is fast ventricular filling bc atrioventricular valves are opened Phase 7 is slow ventricular filling bc pressure in ventricle increases, therefore the pressure gradient across AV is decreased... This causes a decreased ventricular filing