Question

Fick's Law of diffusion (p. 137 Silverthorm) governs the rate at which oxygen moves from the alveolar space to the blood where: Explain how each condition below affects gas exchange by indicating which factor affecting the rate of diffusion is influenced (surface area, concentration gradient, or membrane permeability.) In each case state whether the factor increases or decreases the rate of gas exchange. In addition to the properties of membranes above, you will also need to consider the factor of diffusional distance! Congestive heart disease Emphysema Asthma Climbing to high altitude Receiving supplement oxygen at the hospital A mountain climber ascends to an altitude where the partial pressure of oxygen in the atmosphere is very low. What immediately happens to the climber's ventilation rate? Which chemoreceptor (oxygen or carbon dioxide/pH) would cause this change in ventilation rate?

Answer 1

During congestive heart disease there is a reduced efficiency of gas exchange

In emphysema, the gas exchange reduces. The surface area available for gas exchange is reduced.

A fall in inspired oxygen pressure at higher altitude reduces the driving pressure for gas exchange in the lungs