7.5 the cardiac cycle

Question 1

meaning of diastole

Answer 1

relaxation of heart muscle

Question 2

describe the diastolic process.

Answer 2

1- atria fills with blood
walls of atria expand, increase in blood pressure until exceeds pressure in ventricles

2- AV valves open and ventricles fill with blood, aided by gravity
therefore pressure in ventricles lower in aorta and pulmonary artery

3- semi-lunar valves close

Question 3

describe the atrial systole process.

Answer 3

atria walls contract
-> pushes all remaining blood into ventricles

Question 4

describe the ventricular systole process.

Answer 4

1- ventricles contract after atrial systole
-> delayed wave of contraction
-> higher blood pressure in ventricles (higher pressure in atria)
- AV valves close

2- semi-lunar valves open
(when pressure in ventricles is larger than pressure in aorta and pulmonary artery

3- blood enters blood vessels under high pressure (due to strong contraction of ventricles)

Question 5

how does blood flow from one direction to the other?

Answer 5

from high pressure to low pressure