Pressure changes (Heart)

Question 1

Systole

Answer 1

Contraction

Question 2

Diastole

Answer 2

Relax

Question 3

Cardiac cycle

Answer 3

Series of events that take place in one heart beat and is a continuous process

Question 4

Atrial systole

Answer 4

Atrium contracts, Pressure increases in atrium and volume decreases. Ventricle relax, Pressure decreases in ventricle. Atrioventricular valve is forced open due to pressure difference and semi-lunar valve is closed so blood moves from the atrium to the ventricle down the pressure gradient

Question 5

Ventricular systole

Answer 5

Ventricle contracts, pressure increases in ventricle and volume decreases, atria relaxes, Pressure in atria is low so atrioventricular valve is forced closed (Prevents backflow of blood) and semi-lunar valve is forced open. Pressure in ventricle is greater than pressure in aorta and pulmonary artery so blood moves out ventricle into arteries away from heart. (During this atria are relaxing so are filling with blood again)

Question 6

Diastole

Answer 6

Ventricle and atria both relax, Pressure in ventricle drops below aorta and pulmonary artery so semi-lunar valve is closed. Blood returns to heart through vena cava and pulmonary vein. Pressure in atria rises above ventricle eventually so the AV is forced open repeating the process again from atrial systole.

Question 7

Factors that affect heart rate

Answer 7

Drugs
Caffeine
Alcohol
Sex
Weight
Height
Temperature
Diet
Dehydration