The role of the nervous system in generating normal breathing rhythm

The heart is able to contract on its own accord but it will be unable to keep a constant rhythm of beating. This is where the Nervous system comes into effect. Impulses are sent from the brain in order to control the speeding up of the heart rate and the slowing down of the heart rate depending on it's need at a particular time.





The nervous system is critical for our every day living and functioning of the body. The Brain is divided into 3 parts, these are the Cerebrum, the Cerebellum and the brain stem. The central controlling area for breathing is situated in the lower part of the Brain stem known as the Medulla Oblongata. Also situated in the Brain stem is the Pons and the Midbrain.
It is the Brain stem along with the spinal cord and medulla oblongata that controls the autonomic functions and the transporting of nerve signals between between brain and spinal cord.(The spinal cord serves as a pathway for the nerve impulses as they travel to and from the brain.)
The autonomic nervous system sends impulses to the vital organs within our body. It functions without conscious effort and controls the heart rate, breathing rate, blood pressure and body temperature.


There are different types of neurons in the body, inspiratory neurons and expiratory neurons are responsible to maintain the normal breathing rhythm. The inspiratory neurons are active when inspiring and inactive when expiring and the expiratory neurons are active when expiring and inactive when inspiring. The neurons are sent to the diaphragm and intercostal muscles with messages signalling them to contract and relax at regular intervals.

There are two different nerve cells that detect the levels of change in oxygen and carbon dioxide. These are pheripheral chemoreceptors and central receptors. The pheripheral chemoreceptors monitor the levels of oxygen in the blood, if the oxygen decreases then they send messages to the respiratory centre to increase the rate and depth of breathing. Carbon dioxide is censored by both receptors. The central receptor is situated in the medulla. It monitors the levels of carbon dioxide in the cerebrospinal fluid. This fluid surrounds the brain and the spinal cord. If the carbon dioxide levels are too high then the receptors are triggered, they send impulses to the respiratory centre to increase the breathing rate allowing more oxygen into the blood and allowing the carbondioxide to diffuse into the capilleries so that it can exit the body.