Question

2. Compare and contrast the physiology occurring at the respiratory membrane of the alveoli with that of the filtration membrane of the renal corpuscle. You can highlight their anatomical similarities and differences, but your entire answer should be directed at physiological processes and functions.

Answer 1

In alveolar membrane, oxygen diffuses across the respiratory membrane from the alveolus to the capillary, whereas carbon dioxide diffuses out of the capillary into the alveolus.Although the oxygen solubility in blood is not high, drastic difference ca be observed in the partial pressure of oxygen in the alveoli and in the blood of the pulmonary capillaries.The alveolar oxygen partial pressure is approx 104 mm Hg, whereas in capillary blood, it is about 40 mm Hg. The partial pressure difference is approx 64 mm Hg: This large difference in partial pressure results in strong pressure gradient that results in oxygen to rapidly cross the membrane from the alveoli into the blood.Alveolar and capilarry partial pressure od carbon dooxide is also different.the partial pressure is about 5 mm Hg which is less than oxygen. However, The partial pressure of carbon dioxide in the capillary blood is about 45 mm Hg, and in the alveoli is about 40 mm Hg. However, the solubility of carbon dioxide is more than that of oxygen by a factor of about 20- in both blood and alveolar fluids. As a result, the relative concentrations of both the gases( O2 and CO2) that diffuse across the membrane are similar.

In renal corpuscles membrane, the glomerulus produces filtrate when the hydrostatic pressure produced by the heart pushes water and solutes through the filtration membrane. Glomerular filtration is a passive process because cellular energy is not used at the filtration membrane fot filtrate supply. the filtration membrane lies between the blood within the glomerulus and therefore the filtrate within the Bowman’s (glomerular) capsule and this filtration membrane is very fenestrated which permits the passage of small molecules like water, sodium, glucose, etc. The glomerular barrier selects for 2 molecular features: size and charge. because as the relative molecular mass of a molecule increases, its capacity for filtration rapidly declines. Furthermore, for any given sized molecules, its capacity for filtration rapidly declines.