MASS TRANSPORT IN MAMMALS

Question 1

how many polypeptide chains makes up haemoglobin?
what does each chain contain?
how many oxygen biding sites does it have?
what is haemoglobin’s function?

Answer 1

4
haem group- Fe2+
4
carry oxygen to respiring tissues

Question 2

how does concentration of oxygen link to partial pressure?
how does pp link to oxygen affinity?
when and where is affinity high? what is the name of this process?
when and where is affinity low? what is the name of this process?

Answer 2

increased conc means increased pp
increased pp means increased affinity for oxygen
affinity high in lungs when oxygen binds to haemoglobin tightly-loading
affinity low during respiration, oxygen used up (pp decrease) -oxygen released into respiring tissues- unloading

Question 3

whats the bhor effect?

Answer 3

co2 dissolves in blood forming carbonic acid
changes tertiary structure of haemoglobin- lower affinity
more oxygen dissociates at respiring tissues

Question 4

vein
artery
which one goes towards heart, which one goes away?

Answer 4

vein-towards

artery-away

Question 5

which vein supplies deoxygenated blood?

which vessel transports deoxygenated blood from heart to lungs?

Answer 5

vena cava

pulmonary artery

Question 6

which vein supplies oxygenated blood to heart

which artery supplies blood to the body?

Answer 6

pulmonary artery

aorta

Question 7

describe cardiac diastole

Answer 7

atria and ventricles relax- blood enters atria

blood enters, pressure rises, atrioventricular valves open, blood flows into ventricles down pressure gradient

Question 8

describe atrial systole

Answer 8

atria contract forcing remaining blood into ventricles

Question 9

describe ventricular diastole

Answer 9

– contraction of the ventricles causes the atrioventricular valves to
close and semi-lunar valves to open thus allowing blood to leave the left ventricle
through the aorta and right ventricle through the pulmonary artery

Question 10

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Answer 10

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Question 11

why is a double circulatory system useful?

Answer 11

allows high pressure to be maintained

large diffusion distance

Question 12

describe arteries 3
hint: what does it do to control volume
how can it control blood pressure
what does it have to prevent bursting due to high pressure

Answer 12

thick muscular wall- can constrict and dilate to control volume
thick elastic tissue to maintain blood pressure and to allow stretch and recoil
thick wall

Question 13

what is the function of arterioles and describe structure

Answer 13

thick muscle layer to
restrict blood flow into capillaries
thinner elastic layer and wall than arteries

Question 14

describe the structure and function of veins

why is having a thin layer advantageous?

Answer 14

thin muscle layer
thin elastic layer and wall due to low pressure
contain valves to prevent backflow
means it can be flattened

Question 15

capillary structure and function

Answer 15

one cell thick
no muscle or elastic layer
form capillary beds- narrow diameter

Question 16

formation of tissue fluid first step
hint: where does blood enter from
where is there high pressure?

Answer 16

blood enters capillaries from arterioles

high hydrostatic pressure at the arteriole end

Question 17

formation of tissue fluid second step:
what happens?
what remains?what does this do?

Answer 17

molecules like glucose, amino acids, fatty acids, water are forced out- called tissue fluid
proteins remain in capillaries, lowering water potential

Question 18

3rd step: where is there low pressure?

what happens to remaining tissue fluid?

Answer 18

low hydrostatic pressure at the venule end
low water potential at venule end
water moves into the venule end by osmosis
remaining tissue fluid absorbed into the lymphatic system.