Cardiac cycle

Question 1

atrial systole

Answer 1

• muscles in atria walls contract
• pressure in atria is above pressure in ventricles so atrioventricular valves open and bloods from the atria to the ventricles

Question 2

ventricular systole

Answer 2

• muscles in ventricle walls contract
• pressure in ventricles is above pressure in atria so the atrioventricular valves close and semilunar valves open
• blood flows from ventricles to the arteries

Question 3

cardiac diastole

Answer 3

• muscles in walls of atria and ventricles relax
• pressure in ventricles drops below atria so semilunar valves close and atrioventricular valves open
• blood returning to the heart flows under low pressure into the aria

Question 4

myocardial infarction (heart attack)

Answer 4

death to areas of cardiac muscle due to lack of oxygen

Question 5

stroke

Answer 5

sudden death of brain cells due to lack of oxygen

Question 6

angina

Answer 6

a pain in the chest, left arm, neck or jaw caused by a lack of oxygen to heart muscle

Question 7

aneurysm

Answer 7

a localised, blood-filled balloon like bulge in the wall of a blood vessel

Question 8

thrombosis

Answer 8

the formation of a blood clot inside a blood vessel obstructing the flow of blood through the circulatory system