Cardiac function and its control

Question 1

4 phases of the pressure-volume curve

Answer 1

diastole isovolumetric contraction systole isovolumetric relaxation

Question 1

Preload

Answer 1

The stretch on the myocyte fibres before they commencecontraction

Question 2

normal SV

Answer 2

100ml

Question 2

normal EDP

Answer 2

15mmHg

Question 3

Exaplain the Frank Starling relationship

Answer 3

more stretch on the cardiac myocytes by increased venous return (increased EDV), results in more tension in the wall and increased SV

Question 4

What can increase afterload

Answer 4

arterial hypertension LV outflow tract obstruction (eg. aortic stenosis)

Question 5

Afterload

Answer 5

the load encountered by the ventricle as it commences contraction

Question 7

for any volume of blood, the pressure depends on

Answer 7

the compliance of the wall the active tension in the wall

Question 8

stroke volume can be increased by

Answer 8

increasing EDV (increased venous return) increasing ventricular contractility (inotropy)

Question 9

normal ESP

Answer 9

5 mmHg

Question 11

normal ESV

Answer 11

75ml

Question 12

what increases preload

Answer 12

increased venous return