B2 - blood, heart, coronary arteries, CHD

Question 1

what kind of circulatory system do humans have?

Answer 1

double circulatory system

Question 2

what kind of circulatory system do fish have?

Answer 2

single circulatory system

Question 3

Describe the process of the double circulatory system (4)

Answer 3

1. deoxygenated blood pumped from heart –> lungs where it collects oxygen
2. this oxygenated blood then returns to the heart
3. the heart pumps the oxygenated blood to the organs where the blood transfers oxygen to the body cells
4. the blood now returns to the heart

Question 4

what is an advantage of a double circulatory system?

Answer 4

The blood passes through the heart twice, so it can travel rapidly to the body cells, delivering the oxygen that the cells need

Question 5

Blood flow around body/ heart/ lungs (6)

Answer 5

1. oxygenated blood return to the heart via the pulmonary artery
2. it then enters the heart at the left atrium and is pumped into the left ventricle
3. the blood is pumped to the body via the aorta
4. deoxygenated blood returns to the heart via the vena cava
5. it enters the heart at the right atrium and is pumped into the right ventricle
6. The blood travels back to the lungs via the pulmonary artery

Question 6

what does the right ventricle do?

Answer 6

pumps deoxygenated blood to the lungs to take in oxygen. then the blood returns to the heart.

Question 7

what does the left ventricle do?

Answer 7

pumps oxygenated blood around all other organs of the body.

Question 8

what is the role of the vena cava

Answer 8

brings in deoxygenated blood from the body

Question 9

what do the valves do ?

Answer 9

• stop the blood from flowing backwards into the atria when the ventricles contract
• separate the atria and ventricles

Question 10

does the right or left side of the heart have a thicker muscular wall? why?

Answer 10

the left because the left ventricle pumps blood around the entire body so needs to provide a greater force

Question 11

where does the right ventricle pump blood to?

Answer 11

only the lungs

Question 12

how heart uses its 4 chambers to pump blood around (4)

Answer 12

1. blood enters the left atrium and right atrium
2. the atria contracts and the blood is forced into the ventricles
3. the ventricles now contract and force blood out of the heart
4. valves stop the blood from flowing backwards into the atria when the ventricles contract

Question 13

what is your resting heart rate controlled by?

Answer 13

a group of cells in the right atrium wall that act as a pacemaker.
- these cells have a small electric impulse which spreads to the surrounding muscle cells, causing them to contract

Question 14

what are the 3 types of blood vessels and their functions

Answer 14

1. arteries - carry the blood away from the heart
2. capillaries - involved in the exchange of material at the tissues
3. veins - carry blood to the heart

Question 15

Arteries features (4)

Answer 15

1. walls are strong and elastic because the heart pumps blood at high pressures
2. thick walls
3. contain thick layers of muscle to make them strong
4. have elastic fibres to allow them to stretch and spring back

Question 16

Capillaries features (4)

Answer 16

1. are really tiny to see
2. have permeable walls –> so substances can diffuse in and out
3. they supply flood and oxygen and take away waste like CO2
4. walls are usually one cell thick –> increase the rate of diffusion by decreasing the distance

Question 17

what do capillaries join up to form?

Answer 17

veins

Question 18

why do the walls in veins not need to be as thick as the artery walls?

Answer 18

the blood is at a lower pressure in the veins

Question 19

Veins features

Answer 19

1. have a bigger lumen than the arteries —> to help the blood flow despite the lower pressure
2. have valves –> to help keep the blood flowing in the right direction

Question 20

what is the role of conorary arteries?

Answer 20

provide oxygen to the muscle cells of the heart.
- the oxygen is then used in respiration to provide energy for contraction

Question 21

INFO: platelets have NO nucleus

Question 22

which blood vessels carry blood away from the heart?

Answer 22

arteries

Question 23

which chamber in the heart contracts to force blood to the lungs

Answer 23

right ventricle

Question 24

Describe how CHD can cause a heart attack

Answer 24

1. fatty deposits build up on the wall of the coronary artery
2. blood flow is restricted
3. less oxygen reaches the heart muscle so heart muscle cannot respire
4. this results in a heart attack

Question 25

where is cholesterol made and transported?

Answer 25

made in the liver and transported in the blood

Question 26

what cause a buildup of fatty deposits in the artery?

Answer 26

high levels of cholesterol

Question 27

what are statins? what do they do?

Answer 27

drugs that are used to reduce the levels of fatty deposits in the blood
- they block an enzyme in the liver which is needed to make cholesterol

Question 28

what are 3 advantages of statins

Question 29

what is cholesterol?

Answer 29

an essential lipid that the body produces and needs to function properly.

• too much of (LDL) cholesterol = fatty deposits

Question 30

advantage of beneficial heart?

Answer 30

less likely to be rejected by body’s immune system

Question 31

how can the valves in the heart be damaged or weakened? what can it cause?

Answer 31

by heart attacks, infection or old age.
- it can cause the valve tissue to stiffen ir not open properly or become leaky, allowing blood to flow in both directions –> means that the blood doesn’t circulate as effectively as normal

Question 32

what can faulty valves be replaced with?

Answer 32

biological or mechanical valves (2)

Question 33

what are cardiovascular diseases?

Answer 33

diseases of the heart and blood vessels

Question 34

are cardiovascular dieseases communicalble or non- communicable?

Answer 34

non- communicable