Respiratory center
The respiratory center is located in the medulla oblongata
Medulla oblongata
The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...

, which is the lowermost part of the brain stem
Brain stem
In vertebrate anatomy the brainstem is the posterior part of the brain, adjoining and structurally continuous with the spinal cord. The brain stem provides the main motor and sensory innervation to the face and neck via the cranial nerves...

. The RC receives controlling signals of neural, chemical and hormonal nature and controls the rate and depth of respiratory movements of the diaphragm and other respiratory muscles. Injury to this center may lead to central respiratory failure, which necessitates mechanical ventilation
Mechanical ventilation
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...

, but usually the prognosis is grave.

In healthy individuals the presence of elevated carbon dioxide levels in the blood is the stimulant that the RC responds to in order to signal the respiratory muscles to breathe. Chemoreceptors found in carotid and aortic bodies are responsible for detecting this .

Individuals who suffer from Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...

 usually have a chronically elevated level of carbon dioxide present in their blood due to their diminished lung function. As a result, their specific chemoreceptors become desensitised to the hypercapnia
Hypercapnia or hypercapnea , also known as hypercarbia, is a condition where there is too much carbon dioxide in the blood...

 and instead respond to a decreased amount of oxygen present.

The groups of nerve cells in the brain which regulates the respiration rhythmically are collectively known as respiratory centers.

Inspiratory centre (Dorsal respiratory group)

  • Location: Dorsal portion of medulla
  • Nucleus: Nucleus tractus solitarius
  • Function: causes inspiration while stimulated.

Expiratory centre (Ventral respiratory group)

  • Location: Antero- lateral part of medulla, about 5 mm anterior and lateral to dorsal respiratory group
  • Nucleus: Nucleus ambiguous and nucleus retro ambiguous.
  • Function: It generally causes expiration but can causes either expiration or inspiration depending upon which neuron in the group are stimulated. It sends inhibitory impulse to the apneustic centre.

Pneumotaxic centre

  • Location: Pons(upper part )
  • Nucleus: Nucleus parabrachialis
  • Function: It controls both rate and pattern of breathing. Limit inspiration.

Apneustic centre

  • Location: Pons(lower part)


a)It discharges stimulatory impulse to the inspiratory centre causing inspiration.

b)It receives inhibitory impulse from pneumotaxic centre and from stretch receptor of lung.

c)It discharges inhibitory impulse to expiratory centre.

Respiratory center depression

Depression of a respiratory center can be a result of next reasons:
  • medical drug action (opioids, sedatives and etc.)
  • sudden cessation of blood circulation in brain
    The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

  • heavy brain trauma
  • sharp neuroinfections
  • brain tumors
  • damage of a brainstem
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