topic 5

Question 1

heart pressure

Answer 1

1. slight increase in (v) due to contraction of muscles in a –> force blood into relaxed v
2. muscles in v begin to contract, the bicuspid valve closes (pressure increases, prevent backflow of blood)
3. (v) continues to increase as muscles contract
4. (v) becomes higher than (A), semi-lunar valves open (blood enters A –> (A) increases)
5. muscles of v begin to relax, semi-lunar valves close (prevent backflow)
6. (v) continues to decrease as muscles in v relax
7. bicuspid valve open as (v) becomes lower than (A)
8. (v) gradually increases as blood continues to enter ventricle from atrium

Question 2

blood plasma

Answer 2

90% water
carries products of digestion, soluble proteins, mineral salts, excretory products, hormones)
all dissolved

Question 3

red blood cells functions

Answer 3

transport oxygen from lungs to all parts of the body

Question 3

rbc adaptations

Answer 3

circular, flattened and biconcave shape (larger sa)
haemoglobin
- combines reversibly with oxygen –> oxyhaemoglobin
mature rbcs lack nucleus
elastic and bell-shaped (squeeze through narrow blood capillaries)

Question 3

wbc functions

Answer 3

ingest and digest foreign particles (phagocytes)
produce antibodies (lymphocytes)

Question 4

functions of blood

Answer 4

transport:
food substances
excretory products
hormones
oxygen
heat

Question 5

clotting of blood

Answer 5

damaged tissues and organs release thrombokinase
~ catalyses conversion of prothrombin into thrombin
~ catalyses conversion of soluble fibrinogen into insoluble threads of fibrin
~ traps rbc and forms a clot

Question 6

antibody production

Answer 6

production by lymphocytes stimulated by pathogens (bacteria / virus)

Question 6

antibody functions

Answer 6

neutralise toxins
destroy bacteria
agglutination

Question 6

antibody details

Answer 6

specific to one infection (immune)
circulates for some time
artificial immunity:
- harmless form of bacteria or virus
- manufacture corresponding antibodies

Question 7

blood network

Answer 7

artery –> capillary –> venules –> veins

Question 7

artery

Answer 7

away
oxygenated
high pressure
thicker
elastic
muscular wall
smaller lumen to diameter

Question 8

vein

Answer 8

toward
deoxygenated
lower pressure
thinner
less elastic
less muscular
skeletal muscle contraction
semi lunar valves
larger lumen to diameter

Question 9

capillary

Answer 9

microscopic
one layer
endothelium
pores, partially permeable
highly branched

Question 10

heart

Answer 10

coronary arteries supply oxygen and nutrients

Question 11

effects of smoking

Answer 11

nicotine: blood clot, release adrenaline, increase risk of coronary heart disease, heart rate and blood pressure increase
carbon monoxide: carboxyhaemoglobin, increase the rate of fatty deposits on inner arterial wall, risk of coronary heart disease, reduce ability of blood to carry oxygen, narrow lumen of arteries and lead to increase in blood pressure
tar: uncontrolled cell division, paralyse cilia lining, increase risk of lung cancer, dust trapped in mucus not removed leading to chronic bronchitis and emphysema