Control of respiration

Control of Respiration

The control of respiration is a complex physiological process that involves the regulation of breathing to meet the metabolic demands of the body. This process ensures that oxygen is delivered to tissues and carbon dioxide is removed from the body. The control of respiration is primarily managed by the respiratory centers in the brain, which respond to various chemical and neural signals.

Respiratory Centers

The primary respiratory centers are located in the medulla oblongata and the pons of the brainstem. These centers include:

• Medullary Respiratory Center: This includes the dorsal respiratory group (DRG) and the ventral respiratory group (VRG). The DRG is primarily responsible for the basic rhythm of breathing, while the VRG is involved in forced breathing.
• Pontine Respiratory Group: This includes the pneumotaxic center and the apneustic center, which help regulate the rate and pattern of breathing.

Chemoreceptors

Chemoreceptors play a crucial role in the control of respiration by detecting changes in blood levels of carbon dioxide, oxygen, and pH. There are two main types of chemoreceptors:

• Central Chemoreceptors: Located in the medulla, these receptors are sensitive to changes in the pH of cerebrospinal fluid, which reflects the level of carbon dioxide in the blood.
• Peripheral Chemoreceptors: Located in the carotid bodies and aortic bodies, these receptors respond to changes in blood oxygen levels, carbon dioxide, and pH.

Neural Control

Neural control of respiration involves the integration of signals from various parts of the body. The vagus nerve and the glossopharyngeal nerve carry sensory information from the lungs and chemoreceptors to the brainstem. The brainstem then processes this information and sends motor signals to the respiratory muscles, such as the diaphragm and intercostal muscles, to adjust the rate and depth of breathing.

Reflexes

Several reflexes are involved in the control of respiration:

• Hering-Breuer Reflex: This reflex prevents over-inflation of the lungs by inhibiting inspiration when the lungs are stretched.
• Cough Reflex: This reflex helps clear the airways by triggering a forceful expulsion of air.

Voluntary Control

While breathing is primarily an involuntary process, it can be voluntarily controlled to some extent. The cerebral cortex can override the brainstem centers to alter breathing patterns, such as during speaking, singing, or holding one's breath.

Also see

• Respiratory system
• Gas exchange
• Acid-base balance
• Hypoxia
• Hypercapnia