The Science Behind Breathing: Nervous Control And Reflexes Of Respiration

The Science Behind Breathing: Nervous Control And Reflexes Of Respiration

Describe the nervous regulation of respiration. Add a note on Herring-Breurr’s reflex.
Answer:

Nervous Regulation Of Respiration:

• It is brought about by

1. Automatic control:

• Respiration is involuntary controlled by the respiratory centers
• These respiratory centers are as follows:

2. Voluntary control:

• Respiration can be modifies both in rate and/or depth at will for a specific period only
• The pathway for such a control is via corticospinal tract originating from the cerebral cortex and end on spinal motor neurons
• It innervates the respiratory group of muscles

Herring-Breurr’s reflex Regulation of inspiration:

• Inspiration is regulated by apneustic center
• Activation of apneustic center causes stimulation of inspiratory center
• Inspiratory centre in turn sends impulses via spinal cord to the anterior horn cells
• This results in inspiration

Herring-Breurr’s reflex Regulation of expiration:

1. Inspiratory neurons from the inspiration center sends excitory impulses to pneumotoxic center

• Pneutoxic center sends inhibitory impulses to apneustic centre

2. During inspiration, pulmonary stretch receptors are stimulated

• This send inhibitory impulses to apneustic centre via vagus nerve

3. Pneumataxic center

• Stimulates expiratory centre
• Inhibits inspiratory centre
• Inhibits apneustic centre
• Thus inspiration is inhibited and expiration occurs passively

Herring Breuer’s Reflex:

• This reflex occur due to stimulation of stretch receptors present on lungs
• It prevents overstretching of lung muscles

• It is also known as Hering Breuer inflation reflex since it occurs due to inflation of lungs