Control of breathing

The goal of the respiratory system is to supply oxygen, remove carbon dioxide, and maintain acid-base balance. Breathing is controlled via feedforward and feedback mechanisms that include three key components: (1) central control, (2) effectors, and (3) sensors (Fig. 8.1). The primary centers for central respiratory control are in the pons and medulla (Fig. 8.2 ). During the wake state, these centers receive input from a variety of sources to modulate breathing (Fig. 8.3). Oxygen and carbon dioxide levels are two of the main chemical signals that modulate breathing (Fig. 8.4). Sleep decreases the ventilatory response to hypoxia and hypercarbia. This effect varies with the stage of sleep (Fig. 8.5).