Heart and Blood

Question 1

the circulatory system is?

Answer 1

a system of tubes with a pump and valves to ensure one-way flow of blood

Question 2

why is it called double circulation?

Answer 2

blood passes through the heart twice for each complete circulation of the body

Question 3

right side:

Answer 3

collects deoxygenated blood from the body and pumps it to the lungs under relatively low pressure

Question 4

left side:

Answer 4

the oxygenated blood then returns from the lungs to the left side of the heart, where the pressure of the blood is raised in order to pump it to all organs of the body

Question 5

advantages of a double circulation

Answer 5

• oxygenated is seperate from deoxygenated: septum ensures complete seperation
• the blood pressure in systemic circulation can be higher than that in the pulmonary circulation.
  • the left ventricle has a thicker wall due to more muscle so it pumps blood under higher pressure to the organs. this means metabolites such as nutrients and oxygen can reach the tissues faster which will speed up all metabolic processes, enhancing heat generation or muscle movement.
  • the right ventricle has a thinner wall to pump blood under a lower pressure to the lungs to avoid lung damage. is pulmonary pressure was equal to systemic, the tissues in the lungs would be damaged as tjey need to be very thin.

Question 6

systemic

Answer 6

body

Question 7

pulmonary

Answer 7

lungs

Question 8

right side of heart

Answer 8

collects deoxygenated

Question 9

left side of heart

Answer 9

pumps oxygenated to body

Question 10

blood is pumped away from the heart into_______ and the blood returns in ________

Answer 10

arteries (a away)

veins

Question 11

what are coronary arteries used for?

Answer 11

provide heart muscle with oxygen and glucose as cardiac muscle does not tire

Question 12

the two upper chambers are called the ______. the two lower chambers are called the ______

Answer 12

atria (a above)

ventricles

Question 13

the right atrium receives blood from the _______ ______. the left atrium receives blood from the ________ ________.

Answer 13

vena cava

pulmonary vein

Question 14

what do the bicuspid and tricuspid valves fo?

Answer 14

prevent backflow of blood, ensuring blood flows only from the atria to the ventricles

Question 15

the right ventricle pumps blood into the _____

the left ventricle pumps blood into the ________.

Answer 15

pulmonary artery

aorta

Question 16

what do the semilunar valves do?

Answer 16

they allow blood to move upwards into the arteries from the ventricles but prevent blood from flowing in the opposite direction

Question 17

why is the blood in the aorta under higher pressure than in the pulmonary artery?

Answer 17

the wall of the LV is much thicker than the RV as it needs to pump blood around the body. so the blood in the aorta is under higher pressure as it carries blood under high pressure around the body

Question 18

heart: to and from

Answer 18

to heart: vena cava and pulmonary vein

from heart: pulmonary artery and aorta

Question 19

lungs: to and from

Answer 19

to lungs: pulmonary artery

from lungs: pulmonary veins

Question 20

kidneys to and from

Answer 20

to kidney: renal artery

from kidney: renal vein

Question 21

describe coronary heart disease

Answer 21

• coronary arteries supply blood containing glucose and oxygen to the heart muscles
• if a coronary artery gets blocked the cardiac muscle runs short of oxygen
• this blockage is called CHD
• the cardiac muscle cannot respire—> no energy to contract and pump blood
• the heart stops beating: heart attack/cardiac arrest

Question 22

cause of CHD: poor diet with too much saturated fat

Answer 22

• saturated fat can be converted into cholesterol which builds up in the arteries.
• individuals with hereditary high levels of blood cholesterol are more prone to developing CHD

Question 23

cause of CHD: smoking

Answer 23

• nicotine damages the heart by reducing the elasticity of blood vessels

Question 24

stress:

Answer 24

stress causes and increase of blood pressure: can result in fatty materials depositing in arteries

Question 25

genetic predisposition:

Answer 25

DNA determines the size of the arteries, so characteristics of the heart are passed onto the offspring

Question 26

age CHD

Answer 26

the risk of coronary heart disease increases with age. about 80% of people who die of CHD are 65 or above

Question 27

gender:

Answer 27

mainly affects men of 45/55 women during menopause rarely suffer as the hormone oestrogen protects them

Question 28

explain the effect of physical activity on the heart rate

Answer 28

- during exercise muscle cells must contract so they require more energy. so they need more glucose and oxygen per minute. - the heart rate must increase to provide cells with more glucose and oxygen and to remove tje co2 produced during exercise normal heart rate is about 70 beats a minute the rate becomes lower the fitter you are

Question 29

artery structure

Answer 29

- thick tough wall with muscles and elastic tissue // to withstand and maintain blood pressure (prevents bursting) - narrow lumen // maintains high blood pressure - valves absent /// none needed as high pressure prevents backflow of blood

Question 30

vein structure

Answer 30

- thin wall with less muscles and elastic tissue// allows muscles to exert pressure on the veins - wide lumen // allows great volume of blood to pass and reduces resistance to blood flow valves present // prevent backflow of blood

Question 31

capillary structure

Answer 31

permeable wall (one cell thick) no muscle or elastic tissue // allows diffusion of materials between capillary and surrounding tissue. pores in the wall allow white blood cells to exit luman approximately one red blood cell wide // narrow lumen allows blood cells to pass thru slowly and increases oxygen diffusion from red blood cell

Question 32

red blood cells function

Answer 32

red due to haemoglobin which binds to oxygen so the red blood cell can transport oxygen to the tissues

Question 33

white blood cell function

Answer 33

fight infection vy phagocytosis and antibody production

Question 34

platelets

Answer 34

cause blood clotting

Question 35

plasma

Answer 35

transport of blood cells, ions, soluble nutrients, hormones and carbon dioxide. NC BISH

Question 36

antibody production:

Answer 36

- all cells have proteins on their surface called antigens - lymphocytes recognize foreign antigens on foreign cells (such as bacteria) and make antibodies against them - a different antibody is used for each antigen - some antibodies make bacteria clump together in preparation for action by phagocytosis

Question 37

tissue rejection:

Answer 37

- transplants involve replacing a damaged organ with a donor organ - however lymphocytes detect the foreign antigens of the donor organ and make antibodies to it - the donor organ is rejected as antibodies fight the foreign tissue - the donor organ needs to be from similar tissue (3‘e.g from a relative) - immunosuppressive drugs are user, which switch off the bodys immune response - however the drawback of these drugs are that the patient needs to be kept in isolation as they are at the risk of dying from any diseases they are exposed to.

Question 38

phagocytosis

Answer 38

phagocytes have the ability to move out of capillaries to the site of infection they then engulf and ingest the infecting pathogens and kill them by digesting them

Question 39

features of alveoli

Answer 39

- large surface are so that a lot of gas particles can be exchanged at one time - they are in contact with a dense network of capillaries for quick exchange of gases - thin wall —> short diffusion distance - well ventilated —> high diffusion gradients are maintained for gas exchange

Question 40

role of goblet cells, mucus, ciliated cells

Answer 40

goblet cells produce a sticky substance called mucus which traps pathogens and particles in the inhaled air the ciliated cells then waft this mucus with the trapped pathogens and particles upwards to the throat where it is then swallowed

Question 41

smoking can cause

Answer 41

chronic obstructive pulmonary disease COPD CHD lung cancerw

Question 42

nicotine

Answer 42

a small chemical which diffuses across the alveoli into the blood in the blood plasma to all parts or the body it causes narrowing if the coronary arteries, increases blood pressure, addiction

Question 43

carbon monoxide

Answer 43

this is a gas which diffuses across the alveoli into the blood in the capillaries. it binds to haemoglobin in the red blood cells and therefore reduces the amount of oxygem which the RBC can transport. therefore the body cells receive less oxygen so they cannot respire normally, leading to tiredness.

Question 44

tar

Answer 44

goblet cells produce a abnormally thick mucus. it also paralyses the cilia so mucus trickles down into the alveoli causing a lung infection and breathing problems it also leads to coughing which damages the alveoli thus interfering with gas exchange