Question

A 17-year-old male develops pneumonia, diabetic ketoacidosis, and metabolic acidosis. Respiratory compensation to a metabolic acidosis consists of hyperventilation to lower the arterial PC02. The cause of the hyperventilation is described by which of the following statement?
A. CO2 produced from the reaction of the acid with bicarbonate stimulates central chemoreceptors
B. A decrease in the bicarbonate concentration stimulates ventillation
C. H+ stimulates central chemoreceptors
D. H+ stimulates peripheral chemoreceptors

Answer 1

Answer:

The best answer from the choices, to the question: The cause of the hyperventilation is described by which of the following statement:___, would be, B: A decrease in the bicarbonate concentration stimulates ventilation.

Explanation:

The acid-base balance in the human body, is a very restrictive one. Normal ranges in this base are: 7.35 to 7.45. Whenever the values go either below 7.35 or above 7.45, we are talking about a person going into acidosis or alkalosis. Both situations are pretty serious and they have to do with the balance between the amounts of bicarbonate, and CO2 in the form of carbonic acid, in the blood. The normal ratio of bicarbonate to carbonic acid, is usually 20:1. Chemoreceptors, especially central ones in the neck, measure constantly that the balance is kept and if this is not the case, then several mechanisms will be put into place to recover it. One such measure is respiratory, and the other is metabolic. In the case of this 17-year-old, he has a pneumonia, which means that from the start, one of his recovery mechanisms is impeded, which is the respiratory mechanism of balance. He is also having metabolic problems with his system of compensation because his body is already producing high levels of H+ ions and not enough bicarbonate. Hyperventilation in this person is attempting to expel as much CO2 as possible, to try and restore the balance. The first thing that is sensed by the receptors is the changing in the 20:1 ratio, the increase in pH due to too much carbonic acid, and thus the body initiates the use of CO2 expulsion by the lungs, while metabolic mechanisms come into play.