The heart

structure of heart

the heart has four chambers, the right atrium and ventricle and the left atrium and ventricle

how does blood flow into and out of the heart 1.

deoxygenated blood flows from the body by the vena cava into the right atrium

how does blood flow into and out of the heart 2.

this moves through the right ventricle and pumped out of the pulmonary artery to the lungs

how does blood flow into and out of the heart 3.

at the lungs the blood is oxygenated and received through the pulmonary vein into the left atrium

how does blood flow into and out of the heart 4.

the oxygenated blood flows into the left ventricle where it is pumped through the aorta around the body

how is the blood kept flowing in the right direction

there are valves which prevent the backflow of blood. There are four valves ; tricuspid (right atrium and ventricle), semilunar (ventricle and artery) semi-lunar and bicuspid(left atrium and ventricle)

what is the heart and how does it beat

the heart is a muscle so each time it pumps it contracts and relaxes

heart walls thickness

the left ventricle is much thicker than the right as it needs more muscle as it has to pump blood around the whole body whereas the right ventricle only has to pump to the lungs. This means there is higher blood pressure in the left ventricle.

how does exercise affect respiration

when you exercise your muscles need more energy so you respire more. For more respiration, your body needs to pump more oxygen to cells and removed more carbon dioxide.

how does exercise affect heart rate

as exercise increases, carbon dioxide levels in blood increase. this is detected by receptors in aorta and carotid artery. This sends signals to brain which sends signals to heart causing it to contract more often and with more force.

how does adrenaline affect heart rate

adrenaline binds to specific receptors in heart which causes cardiac muscle to contract more often and with more force so there is an increased oxygen supply to tissues so the body can fight or flight.

coronary heart disease

coronary arteries that supply the blood to the heart muscle gets blocked by layers of fatty material building up. this causes arteries to narrow so blood flow is restricted and there is a lack of oxygen in heart which can cause a heart attack

what increases risk of coronary heart disease

diet high in saturated fat as this leads to fatty deposits, smoking as this increases blood pressure which damages arteries as well as chemicals from smoke making it more likely fatty deposits will form, being inactive as leads to high blood pressure which damages lining of arteries so more likely fatty deposits will form.

What chamber of the heart are peacemaker cells found in?

Right atrium

What do peacemaker cells do?

Control heart rate.