Heart and Cardiac cycle

Question 1

Describe the flow of blood

Answer 1

Vena cava - right atrium - AV - Right ventricle - SLV - pulmonary artery - Lungs - Pulmonary Veins - Left atrium - AV - Left ventricle - SLV - Aorta - Arteries - Arterioles - Capillaries - Venules - Veins

Question 2

Describe atrial systole

Answer 2

Blood under low pressure flows into the atria from the pulmonary vein (left) and vena cava (right). As atria fill pressure increases and atrioventricular valves pushes them open and blood starts leaking into the ventricles.
The atria walls the contract forcing more blood into the ventricles.

Question 3

Describe ventricular systole

Answer 3

Ventricles contract from base upwards increasing the pressure, pushing the blood up and out through semilunar valves into the aorta on the left side and the pulmonary artery on the right side.
The pressure of blood against the atrioventricular valves closes them and prevents and prevents back-flow into the atria.

Question 4

Describe diastole

Answer 4

Atria and ventricles relax during diastole. Elastic recoil lowers pressure in the atria and ventricles.
Blood under higher pressure in the arteries is drawn back towards the ventricles, closing the semi-lunar valves and preventing further backflow.
AV valves are closed as well
Heart is filing with blood

Question 5

Describe the consequences of atherosclerosis (CHD)

Answer 5

Limits the amount of oxygen rich blood reaching the muscle casing angina
Respires anaerobically
If fatty plaque in the coronary arteries rupture, collagen is exposed leading to rapid clot formation, blood supply is blocked

Question 6

Describe ischaemic

Answer 6

Heart muscle supplied by these arteries don’t receive any blood causing a heart attack

Question 7

Describe the consequences of atherosclerosis (stroke)

Answer 7

If supply of blood to the brain is interrupted briefly then a mini stroke may occur - warning of problems
Brain is starved of oxygen

Question 8

Whats systolic blood pressure?

Answer 8

The measure of the blood pressure as the blood leaves the left ventricle and moves into the aorta (the artery that supplies the body with blood)
When blood pressure is measured this is (normally) the higher value of the two values

Question 9

Whats diastolic blood pressure?

Answer 9

The measure of the blood pressure in the arteries when the heart rests between beats. When blood pressure is measured this is the lower value of the two values.