Neural regulation of respiration. Physiology and pathophysiology.

The central nervous system links the body's metabolic demands with the neuromuscular act of breathing. Automatic and voluntary control systems function together to adjust ventilation in response to chemical and somatic signals. Excitatory or inhibitory outputs from higher brain centers descend the spinal cord and influence the motoneurons to the respiratory muscles. Lesions at any level can disrupt the normal respiratory pattern and may or may not produce alveolar hypoventilation. Several neurologic diseases of importance in veterinary practice may affect the respiratory system. Ventilatory insufficiency tends to occur late in the progression of these disease. Prompt localization of the lesion and correction of the underlying dysfunction is often critical to patient survival.