Question

1. Regulation of Blood pH.

   1. Describe the details of external respiration (what moves, where, how, and why?)

   2. If the blood becomes too acidotic, what happens to the rate of respiration? Explain why.

Answer 1

Blood pH can be regulated by the renal system and the respiratory system.

CO2 in the blood readily reacts with water to form carbonic acid, and the levels of CO2 and carbonic acid in the blood are in equilibrium. When CO2 levels rises in blood it reacts with water to form carbonic acid, which will reduce the pH of the body, in response to this respiratory system acts by increasing the rate and depth of breathing so that excess carbon di oxide is removed from the body so that the normal pH is restored, when the CO2 levels are low. this will increase the pH, in response to this the respiratory system act by slowing the rate and depth of breathing so that CO2 is retained, restoring the normal PH.

The renal system help control acid-base balance by excreting hydrogen ions and generating bicarbonate that helps maintain blood plasma pH within a normal range.

External respiration occurs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air. The primary components of external respiration are the surface area of the alveolar membrane and the partial pressure gradients of the gasses. Partial pressure of oxygen in alveoli is high but the partial pressure of oxygen in the blood of capillary is low, this large diffrence in the pressure will cause oxygen to diffuse frm the alveoli into the blood, but when it comes to partial pressure of CO2, it is opposite, the partial pressure for CO2 is low in the alveoli and high in the capillary, this difference in the partial pressure will drive CO2 out from the capillary to the alveoli to be expelled out by the lungs.

If the blood becomes Acidotic, the pH of blood will decrease, this occurs because there is excess CO2 in the body, CO2 in the body reacts with water to form carbonic acid, which will cause the blood to be acidic, in response to this the lungs act by increasing the rate and depth of breathing so that excess CO2 is expelled out to restore the normal pH.