b3.2 transport

Question 1

progression to heart attack [4]

Answer 1

1. atheroma
2. anigma
3. thrombosis
4. heart attack

Question 2

atheroma

Answer 2

• fat deposits in coronary arteries
• blockage as an occlusion

Question 3

anigma

Answer 3

• pain in chest
• symptom: shortness of breath

Question 4

thrombosis

Answer 4

formation of blood clot

Question 5

what is thrombosis caused by

Answer 5

fatty deposits in the artery wall becoming impregnated with calcium salts
- hardens the artery
- inner surface becomes rough

Question 6

what will hypertension cause

Answer 6

increased risk of thrombosis

Question 7

heart attack

Answer 7

when blood clots block the blood flow to part of the muscular wall of heart
- deprives it of oxygen
- prevents normal contractions

Question 8

causes of coronary artery occlusion [9]

Answer 8

1. hypertension
2. smoking
3. consuming too much saturated fat and cholesterol
4. obesity
5. high salt intake
6. too much alcohol
7. sedentary lifestyle
8. genetic predisposition
9. old age

Question 9

tunica externa

Answer 9

tough outer layer of connective tissue with collagen fibres

Question 10

tunica media

Answer 10

thick layer containing smooth muscle and elastic fibres made of protein elastin

Question 11

tunica intima

Answer 11

• smooth endothelium forming the lining of artery

Question 12

importance of thick muscle layer

Answer 12

make arteries strong enough to withstand high and variable blood pressure without bulging outwards

Question 13

importance of large amount of elastic tissue

Answer 13

• reduces the amount of energy expended in transporting blood to the organs of the body

Question 14

when elastic tissue is stretched

Answer 14

store potential energy

Question 15

how does the elastic tissue return the energy

Answer 15

recoiling and squeezing the blood in the lumen

Question 16

importance of semilunar valves

Answer 16

prevents back flow of blood to heart and forces it towards the organs

Question 17

differences between arteries and veins [5]

Answer 17

wall: thicker vs thinner
lumen: narrower vs wider
section: section vs section/flattened
inner surface: corrugated vs no corrugation
fibres: visible in the wall vs no visible (or only few are)

Question 18

how does blood move

Answer 18

by gravity and muscular movement

Question 19

why does the lymph move slowly

Answer 19

no pump to assist in movement
- close to muscles so aided by muscle contraction

Question 20

where is deoxygenated blood + lymph

Answer 20

right atrium

Question 21

what do lymph contain [8]

Answer 21

1. lipids
2. lymphocytes
3. blood plasma
4. wbc
5. waste
6. water
7. minerals
8. proteins

Question 22

why cant the pressure be high when pumping to the lungs

Answer 22

alveoli will burst

Question 23

what happens to blood flow when pressure increases

Answer 23

• blood can go long distances
• increases metabolism
• homeostasis

Question 24

why can fishes only have single circulation

Answer 24

• surrounding water prevents capillaries from bursting
• travelling quickly- increases diffusion
• quick exchange of nutrients

Question 25

pressure from artery

Answer 25

high - doesnt have to be oxygenated

Question 26

path of blood

Answer 26

artery -> arterioles -> capillaries -> venules ->veins -> heart

Question 27

capillary action

Answer 27

- tissue fluid squeezes past - blood plasma + wbc leak out form blood in capillaries

Question 28

pacemaker

Answer 28

generates an electrical signal that causes the upper heart chambers (atria) to contract

Question 29

what is the pacemaker also known as

Answer 29

SA node

Question 30

how does the heart beat [7]

Answer 30

1. myogenic so generate own electrical signal 2. SA node indicated electrical impulse for heartbeat 3. electrical impulse travels along walls of atrium -> contracts 4. electrical impulse moves along to the atrioventricular node (AV node) 5. delay for 0.1 sec to let all the blood travel ventricles 6. AV node sends another electrical impulse down the Purkinje fibre in the bundle of His of the septum and ventricle walls 7. vesicles contracts and blood leaves the heart

Question 31

myogenic cells

Answer 31

can generate their own electrical impulse for muscle contraction

Question 32

factors that change the pace of pacemakers

Answer 32

1. adrenaline 2. blood ph - decreases when co2 increases

Question 33

what is the pace of pacemaker signalled by

Answer 33

medulla oblongta

Question 34

nerve that causes pacemaker to speed up

Answer 34

sympathetic nerve

Question 35

nerve that causes pacemaker to slow down

Answer 35

vagnus nerve

Question 36

properties of water molecules that permit them to move upwards in plants

Answer 36

1. water molecules are polar so can form hydrogen bonds 2. cohesion between water molecules allows continuous water columns 3. adhesion of water to the walls of xylem vessel helps water rise 4. water evaporates at environmental temperatures allowing transpiration pull

Question 37

Describe the distribution of vascular tissues in the stem of dicotyledonous plants

Answer 37

- stem vascular tissue is in bundles - bundles form a ring - phloem is towards outside «of bundle» - xylem is towards centre «of bundle»

Question 38

which blood vessel connected to the heart does blood have the lowest carbon dioxide cocnetration

Answer 38

pulmonary vein

Question 39

what helps to keep blood flowing onwards away from the heart in an artery

Answer 39

elastic fibres

Question 40

when will pressure in the left atrium decrease

Answer 40

as left ventricle fills up

Question 41

how increase in co2 concentration affects the release of oxygen to respiring cells

Answer 41

- lower the pH of the blood - decreased affinity of the haemoglobin for oxygen so greater release of oxygen oxygen dissociation curve shifts to the right