Haemoglobin And Mass Transport In Animals

Question 1

What’re the characteristics of haemoglobin ?

Answer 1

1. Quaternary protein (4 polypeptide chains)
2. Each chain has haem group
3. Haem group contains iron ion
4. Iron ion associates with O2 molecule
5. Haemoglobin carry 4 O2
6. O2 and haemoglobin form to make oxyhaemoglobin
7. Amount of O2 combined to haemoglobin refers to % saturation of haemoglobin

Question 2

Why is O2 dissociation curve S shaped ?.

Answer 2

1. First O2 binds to iron ion slowly so start of curve isn’t steep
2. Causes tertiary structure of haemoglobin to change
3. This exposes remaining O2 binding sites so easier for rest if O2 to bind making curve steep
4. Curves flattens when most of haemoglobin has been saturated

Question 3

What is the circulatory system made of ?

Answer 3

Heart and blood vessels

Double pump system

Question 4

What does vena cava do ?

Answer 4

Carry blood from body to right atrium

Question 5

What’s does pulmonary artery do ?

Answer 5

Carry blood from right ventricle to lungs

Question 6

What does pulmonary vein do ?

Answer 6

Carry blood from lungs to left atrium

Question 7

What does aorta do ?

Answer 7

Carry blood from left ventricle to rest of body

Question 8

What does renal artery do ?

Answer 8

Carry blood from heart to kidney

Question 9

What does renal vein do ?

Answer 9

Carry blood from kidney to heart

Question 10

What do coronary arteries do ?

Answer 10

Supply blood to cardio muscle

Question 11

What are the stages of cardiac cycle ?

Answer 11

1. VENTRICLES RELAX, ATRIA CONTRACT
2. VENTRICLES CONTRACT, ATRIA RELAX
3. VENTRICLE RELAX, ATRIA RELAX

Question 12

What’s cardiac output ?

Answer 12

Volume of blood pumped out left ventricle per min

Stroke volume x heart rate

Question 13

What’s the role and features of arteries ?

Answer 13

ROLE: carry blood away from heart
FEATURES:
- thick muscle wall withstands high pressure
- elastic tissue to stretch when ventricles contract and recoil when ventricles relaxes
- endothelium to reduce friction
- aorta wall has fibrous protein to withstand high pressure

Question 14

What’s the role and features of arterioles ?

Answer 14

ROLE: carry blood from arteries to capillaries
FEATURES:
- muscular layer thicker to allow for contraction and constriction of lumen
- thinner elastic layer as pressure is lower

Question 15

What’s the role and features of veins ?

Answer 15

ROLE: carry blood to heart
FEATURES:
- thin muscle layer
- thinner elastic elastic layer
- valves to prevent back flow
- skeletal muscles contact veins compress increasing pressure of blood in them
- wide lumen to reduce friction

Question 16

What’s the role and features of capillaries ?

Answer 16

ROLE: exchange substances between cells and capillaries
FEATURES:
- one cell thick
- walls are permeable
- fenestrations to allow large molecules to leave
- narrow lumen reduce flow rate giving more time for diffusion
- endothelium cells smooth and flat reduced friction and shortens diffusion pathway

Question 17

How is tissue fluid formed ?

Answer 17

1. Change in BP from high to low from artery to vein forms hydrostatic pressure
2. Fluid is made from blood plasma containing amino acids, glucose, ions etc and is forced out capillaries into space around cells
3. Large molecules such as platelets, plasma proteins remain in capillaries
4. Blood love towards venous side of capillary and water potential decreases
5. Higher water potential in tissues fluid means it goes back into capillary via osmosis
6. Any remaining tissue fluid that’s not been re absorbed in capillaries is drained via lymphatic capillaries

Question 18

What are risks faces for cardiovascular disease ?

Answer 18

Gender
Age
Genetics
Stress
Smoking a