7.4- THE STRUCTURE OF THE HEART

Question 1

What is the heart?

Answer 1

muscular organ that lies in the thoracic cavity behind the sternum (breastbone)

Question 2

How long does the heart operate?

Answer 2

operates continuously + tirelessly throughout life of organism

Question 3

What is the human heart really?

Answer 3

two separate pumps lying side by side

Question 4

What does the left pump of the heart deal with?

Answer 4

oxygenated blood from lungs

Question 5

What does the right side of the heart deal with?

Answer 5

deoxygenated blood from body

Question 6

What are the names of the two chambers that each pump of the heart has?

Answer 6

atrium

ventricle

Question 7

What is the atrium?

Answer 7

thin-walled + elastic + stretches as it collects blood

Question 8

What is the ventricle?

Answer 8

thick muscular wall as it has to contract strongly to pump blood some distance, either to lungs or rest of body

Question 9

Why does blood have to pass through tiny capillaries in the lungs?

Answer 9

to present a large SA for exchange of gases

Question 10

What does blood having to pass through tiny capillaries in the lungs cause?

Answer 10

very large drop in pressure + so blood flow to rest of body would be very slow

Question 11

What do mammals have as the blood pressure drops due to blood passing through tiny capillaries in the lungs?

Answer 11

mammals have system in which blood returned to rest of body

Question 12

What is it essential to separate in the heart?

Answer 12

essential to keep oxygenated blood in pump on left side separate from deoxygenated in pump on right

Question 13

Where does the right ventricle only pump blood to

Answer 13

pumps bloody only to lungs

Question 14

What is the muscular wall of the right ventricle like in comparison to the left ventricle?

Answer 14

thinner muscular wall than left ventricle

Question 15

Why does the left ventricle have a thick muscular wall?

Answer 15

enables it to contract to create enough pressure to pump blood to rest of body

Question 16

How do both the pumps of the heart pump? (hint-time)

Answer 16

pump in time with each other

Question 17

How do both the atria and ventricle contract?

Answer 17

both atria contract together + then both ventricles contract together, pumping same volume of blood

Question 18

What is between each atrium + ventricle?

Answer 18

valves

Question 19

What do the valves between each atrium + ventricle do?

Answer 19

prevent backflow of blood into atria when ventricles contract

Question 20

What are the two valves

Answer 20

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

Question 21

What is each of the four chambers of the heart connected to?

Answer 21

large blood vessels that carry blood towards or away from heart

Question 22

Where do the ventricles pump blood to?

Answer 22

pump blood away from heart + into arteries

Question 23

Where do the atria receive blood from?

Answer 23

receive blood from veins

Question 24

What are pulmonary vessels?

Answer 24

vessels connecting the heart to the lungs

Question 25

What is the aorta connected to?

Answer 25

connected to left ventricle

Question 26

What does the aorta carry?

Answer 26

carries deoxygenated blood to all parts of body except lungs

Question 27

What is the vena cava connected to?

Answer 27

right atrium

Question 28

What does the vena cava bring?

Answer 28

brings deoxygenated blood back from tissues of body (except lungs)

Question 29

What is the pulmonary artery connected to?

Answer 29

right ventricle

Question 30

What does the pulmonary artery carry?

Answer 30

deoxygenated blood to lungs, where its oxygen replenished + its CO2 removed

Question 31

Unusually for an artery. what type of blood does the pulmonary artery carry?

Answer 31

carries deoxygenated blood

Question 32

Is the oxygenated blood passing through the left side of the heart used to meet its own great respiratory needs?

Answer 32

no

Question 33

Which blood vessels supply blood to the heart muscle?

Answer 33

coronary arteries

Question 34

Where do the coronary arteries branch off?

Answer 34

branch off aorta shortly after it leaves the heart

Question 35

Example of how the coronary arteries can be blocked?

Answer 35

by blood clot

Question 36

What do blockages of the coronary arteries lead to?

Answer 36

myocardial infarction or heart attack as an area of heart muscle deprived of blood + so oxygen also

Question 37

What happens to area of heart deprived of blood?

Answer 37

muscle cells in this region unable to respire (aerobically) + so die