AP8

Question 1

What is the equation for rate of gas exchange?

Answer 1

r=(∆P x A x T x S)
(D x √Mw)

r= rate of diffusion
∆P= difference in partial pressure
A= surface area
T= temperature
S= solubility
D= distance
Mw= molecular weight

Question 2

Describe insects 3 ventilation mechanisms

Answer 2

1) Trachea inflate and deflate pumping air through
2) Rhythmic body movements
3) Tidal ventilation

Question 3

What are 3 ways insects balance oxygen intake with loss of water?

Answer 3

1) Spiracles open and close indifferent environmental conditions
2) Hairs around spiracles trap water
3) Air sacs can store air for when spiracles are closed

Question 4

Describe how temperature affects haemoglobin saturation in closed circulatory systems

Answer 4

• Increased temp= decreased affinity of haemoglobin for oxygen- oxygen disassociates
• Tissues that respire rapidly produce a lot of heat, increased c02 supply to respiring tissues

Question 5

Describe how pH affects oxygen affinity?

Answer 5

• Lower pH= lower 02 affinity of haemoglobin
• Higher C02 levels = Lower pH
• Additional oxygen released

Question 6

Describe bird ventilation

Answer 6

• Each breath takes 2 inhalations and exhalations
• Anterior and posterior air sacs
• Air sacs push air through lungs and out the body

Question 7

What are 4 adaptions for gas exchange in birds?

Answer 7

1) Air sacs expand and contract
2) Unidirectional flow of air= increased concentration gradient
3) Crosscurrent flow of air and blood
4) Huge surface area for gas exchange

Question 8

Describe the ventilation system in mammals

Answer 8

Inhalation:

• Intercostal muscles contract
• Diaphragm contracts
• Pressure decreases
• Air rushes in

Exhalation:

• Intercostal muscles relax
• Diaphragm relaxes
• Pressure increases
• Air forced out

Question 9

What are 2 adaptions of mammals to aid ventilation?

Answer 9

1) Lungs inside body, decreases water loss

2) Alveoli have large surface area, 1 cell thick

Question 10

What is a limitation of mammals ventilation?

Answer 10

Tidal ventilation- air enters and leaves through the same path

• not all air is exchanged
• % of air that is oxygen is lower within lungs than in outside air

Question 11

3 adaptions of marine mammals ventilation systems

Answer 11

1) Store oxygen in muscles
2) More efficient at extracting oxygen
3) Can temporarily cut off circulation to some parts of the body