Lungs (2.1)

Question 1

Explain the anatomical adaptations in organisms with respiratory systems that maximise gas exchange

Answer 1

The lungs contain small sacks called alveoli which have a high surface area:volume ratio. The exchange surface of the alveoli is also very very thin allowing for a shorter diffusion pathway.

Question 2

Give the formula for Fick’s Law

Answer 2

Rate of diffusion= SA x diff in conc/
Thickness of gas
Exchange surface

Question 3

Explain how each of these factors would alter the rate of gas exchange.
a) Increased thickness of gas exchange surface due to thicker mucus
b) Reduction in the concentration gradient between the alveolar space and capillaries
c) Damage to alveoli resulting in a reduction in their number

Answer 3

A) having an increased thickness of exchange surface would result in a slower rate of gaseous exchange, as particles have to travel further across membrane due to the added mucus layer.
B) by reducing the concentration gradient, it would result in a much slower rate of gas exchange due to a much shallower conc difference. By reducing the gradient it increases the time.
C) if the alveoli number is reduced, this decreases rate of diffusion due to a decrease in surface area to volume ratio. Raising the overall number to be divided by thickness.

Question 4

Explain the role of goblet cells in the respiratory system

Answer 4

Goblet cells secrete mucus which acts as a protective layer in the respiratory system. This is because it traps dust and other small microorganisms before they can enter the lungs and affect the body.

Question 5

Explain the role of ciliated epithelial cells in the respiratory system

Answer 5

Ciliated epithelial cells act as a propelling force for mucus so it can be transported along the airways.