Disorders of Central Respiratory Control

Abstract

The respiratory control system is designed to regulate oxygen, CO₂, and acid-base balance within a narrow range, under conditions of changing state, airway resistance, energy expenditure, and environmental conditions. The central respiratory pattern generator network is located in the brainstem and receives input from the cortex, hypothalamus, lung, chest wall, extremities, cardiovascular system, emotional centers, chemoreceptors (central/peripheral), and upper airway. The respiratory control system is highly redundant with neural or chemical inputs predominating under different circumstances. Voluntary control of respiration and various reflex patterns (swallowing, vocalizing, coughing, hiccupping) can override other inputs to the respiratory pattern generator. The peripheral chemoreceptors provide considerable input in seconds following a change in PCO₂, but the central chemoreceptors play a larger role over periods of minutes to hours. Central respiratory output generates force in the upper airway and respiratory pump muscles to adjust airflow to meet physiologic demands. The minute ventilation can be adjusted to between 2 L/min during sleep and over 100 L/min during exercise. This chapter will focus on the influence of central respiratory control on perturbations to a variety of homeostatic mechanisms and disease processes.