the structure of the heart

Question 1

where is the heart located?

Answer 1

thoracic cavity behind the sternum (breast bone).

Question 2

which side of the heart pumps which type of blood?

Answer 2

left side - oxygenated from lungs right side - deoxygenated from body

Question 3

what are the two chambers made of?

Answer 3

atrium - thin-walled and elastic - stretches as it collects blood

ventricles - much thicker muscular wall as has to contract strongly to pump blood either to lungs or rest of body.

Question 4

why is the heart made of two separate pumps?

Answer 4

blood has to fall through tiny capillaries in the lungs, in order to present a large SA for the exchange of gases - a very large drop in pressure - 1 pump = slow circulation

Question 5

why is it essential to keep oxygenated blood to the left side and de-oxygenated blood to the right?

Answer 5

would result in partially oxygenated blood reaching the tissues and the lungs - reduced diffusion in the lungs, limiting the rate of oxygen uptake - supply of oxygen to tissues would be inadequate

Question 6

why does the left ventricle have a thicker muscular wall?

Answer 6

to contract and create enough pressure to pump blood to rest of the body.

Question 7

both sides of the heart…

Answer 7

pump at the same time - both atria and ventricles contract together, pumping the same volume of blood.

Question 8

what is the role of a valve?

Answer 8

prevent backflow of blood into atria when ventricles contract

Question 9

name the two valves in the upper chamber

Answer 9

left atrioventricular (bicuspid)/mitral valve right atrioventricular (tricuspid) valve

Question 10

what is the role of a ventricle?

Answer 10

pumps blood away from the heart and into the arteries

Question 11

what is the role of a vein?

Answer 11

carry blood to the and atria into the heart

Question 12

vessels connecting the heart to the lungs are called…

Answer 12

pulmonary vessels

Question 13

vena cava

Answer 13

connected to the right atrium and brings deoxygenated blood back from the tissues of the body (except the lungs).

Question 14

pulmonary artery

Answer 14

connected to the right ventricle and carries deoxygenated blood to the lungs, where its oxygen is replenished and cO2 is removed.

Question 15

pulmonary vein

Answer 15

connected to the left atrium and brings back oxygenated blood back from the lungs.

Question 16

aorta

Answer 16

connected to the left ventricle and carries oxygenated blood to the body (except the lungs).

Question 17

what are the coronary arteries?

Answer 17

hearts own supply of oxygen - branches off the aorta.

Question 18

what happens if the coronary arteries are blocked e.g. blood clot?

Answer 18

leads to myocardial infarction or heart attack - an area of muscle deprived of blood/oxygen - muscle cells in this region unable to aerobically respire and so die

Question 19

what is the septum?

Answer 19

the partition separating the two chambers

Question 20

name the two valves in the lower chamber

Answer 20

semi-lunar valves

Question 21

diagram of heart

Answer 21