Question

How is respiration regulated?

Answer 1

Respiration is under both nervous and chemical regulation.

1. Groups of neurons in the medulla oblongata and pons varolii make up the respiratory centre of the brain. The respiratory centre controls how deeply and how quickly people breathe. The dorsal region of the medulla oblongata contains the neurons that make up the dorsal respiratory group. Inspiration is mostly caused by this cluster of neurons.
2. The ventrolateral region of the medulla oblongata contains the ventral group of neurons. These have the potential to inspire or deplete. The dorsal region of the pons varolii contains the pneumotaxic centre.
3. Only the inspiratory neurons in the ventral respiratory group receive signals from it; all other neurons in the dorsal respiratory group receive them. Its main function is to restrict inspiration.
4. Chemically speaking, the many chemoreceptors found in the aortic and carotid bodies control breathing. The respiratory centre of the brain is primarily stimulated by excess carbon dioxide or hydrogen ions, which also enhance the inspiratory and expiratory impulses to the breathing muscles.
5. Increased CO₂ causes acidosis by lowering pH. Oxygen has very little effect on how the respiratory rhythm is regulated.

Answer 2

The respiratory rhythm centre present in the medulla region of the brain is primarily responsible for the regulation of respiration. The pneumotaxic centre can alter the function performed by the respiratory rhythm centre by signalling to reduce the inspiration rate.

The chemosensitive region present near the respiratory centre is sensitive to carbon dioxide and hydrogen ions. This region then signals to change the rate of expiration for eliminating the compounds.

The receptors present in the carotid artery and aorta detect the levels of carbon dioxide and hydrogen ions in blood. As the level of carbon dioxide increases, the respiratory centre sends nerve impulses for the necessary changes.