The diagram below shows a simplified cross-section of a mammalian alveolus adjacent to a pulmonary capillary.
Fick's Law of Diffusion can be mathematically represented as:
Rate of Diffusion∝A×ΔCx \text{Rate of Diffusion} \propto \frac{A \times \Delta C}{x} Rate of Diffusion∝xA×ΔCwhere:
- A A\,A represents the surface area available for diffusion,
- ΔC \Delta C\,ΔC represents the concentration difference of the gas across the exchange membrane,
- x x\,x represents the diffusion distance (thickness of the membrane).
With reference to the diagram and the variables AAA, ΔC\Delta CΔC, and x x\,x from Fick's Law, explain how the anatomical and physiological features of mammalian lungs are adapted to maximise the rate of oxygen diffusion into the bloodstream.