Part of the TeachMe Series

Neural Control of Ventilation

star star star star star_half
based on 18 ratings

Original Author(s): Chloe Hill
Last updated: 13th January 2021
Revisions: 10

Original Author(s): Chloe Hill
Last updated: 13th January 2021
Revisions: 10

format_list_bulletedContents add remove

Ventilation is the movement of air in and out of the lungs which facilitates gas exchange.  It occurs via the respiratory muscles, which contract and relax rhythmically to fill the lungs with air in inspiration and  empty them in expiration. This article will discuss the neural control of ventilation and its clinical relevance.

Involuntary control

Involuntary respiration is under subconscious control.  The diaphragm and intercostal muscles, the primary respiratory muscles, are stimulated by groups of neurons located in the pons and medulla.  These neurons form the respiratory control centre.  They send impulses to the primary respiratory muscles, via the phrenic and intercostal nerves, which stimulates their contraction.  There are three main groups of neurons involved in respiration:

  • The ventral respiratory group controls expiration
  • The dorsal respiratory group controls inspiration
  • The pontine respiratory group controls the rate and pattern of breathing

Once the neurons stop firing, the inspiratory muscles relax and expiration occurs.

Further information on the mechanics of breathing can be found here.

Fig 1 – Diagram showing the respiratory centres of the brain.

Voluntary Control

Voluntary respiration is under conscious control.  It is controlled via the motor cortex in the cerebrum, which receives inputs from the limbic system and hypothalamus.  The mechanisms involved aren’t completely understood, but signals are thought to be sent to the spinal cord from the motor cortex, which are then passed onto the respiratory muscles.

Fig 2 – Regions of the brain, neurons in the motor cortex are responsible for voluntary control of respiration.

Clinical Relevance – Phrenic nerve paralysis

Phrenic nerve paralysis is where damage to the phrenic nerve results in its dysfunction.  This can cause paralysis of the diaphragm, hence breathing problems and inability of patients to regulate their own breathing.

Common causes include: spinal cord injury, neck injury and surgical complications.