Question

1. The peripheral chemoreceptors are denervated in an experimental animal, and the animal then breathes a gas mixture containing 10 percent oxygen. What changes occur in the animal’s ventilation? What changes occur when this denervated animal is given a mixture of air containing 21 percent oxygen and 5 percent carbon dioxide to breathe?

Answer 1

Peripheral chemoreceptors are located at the bifurcation of common carotid artery. It senses the respiratory condition, the amount of oxygen and carbondioxide present in the blood. And it leads to acclimatization in case of hypoxia.

If the peripheral chemoreceptors are denervated, it leads to abolition of normocapnic response to hypoxia and reduced responce to hypercapnia. It means, in case of hypoxia where oxygen level is too low, the chemoreceptors senses it and helps in increasing the ventilation through peripheral nervous system. In case of hypercapnia where carbondioxide is too high, it helps in reducing respiration. Thus after degenration, the controling of these ventilation get ceased whoch means the ventilation is same in 10% oxygen and 21% oxygen with 5% carbon dioxide. In normal case, ventilation increases and decreases respectively in both cases.