Regulation of Respiration

In the brain the medulla oblongata contains a respiratory center. This
controls breathing. The respiratory center consists of an inspiratory center
and an expiratory center. The axons from the nerve cells of these centres
lead to the intercostals muscle through the intercostals nerves and the
diaphragm via the phrenic nerves.

These nerve fibres transmit impulses to the external intercostal muscles and internal intercostal muscles alternately. The walls of the alveoli have sense endings which are stimulated by changes in the tension of alveolar walls. (Regulation of respiration)

When the alveoli are stretched at the height of inspiration the
receptors send stimuli to the expiratory center of the medulla through the
vagus nerve which inhibits further inspiration. This sequence of events is called
Herring – Breuer reflex. (Regulation of respiration)

In addition the medulla contains a pneumotaxic center which is
connected to the breathing centre and helps to ensure rhythmic breathing.
During inspiration, the inspiratory part of the respiratory center sends
impulses to the pneumotaxic center which responds by sending impulses to
the expiratory part of the respiratory center.

The expiratory center is then activated and so the inspiratory center is inhibited reflexly, respiratory rhythm is controlled in this manner by these centers in the brain. (Regulation of respiration)

Regulation of Respiration

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