Lung ventilation and the physiology of breathing

A 25 year-old male with chest pain, fatique, and altered sensation

“…Autonomic regulation is coordinated by the respiratory nuclei in the medulla and pons. 1,2 These nuclei receive and integrate input regarding serum pH (chemoreceptors in the brainstem, carotid artery, and aortic arch), cardiovascular demand (arterial baroreceptors), thoracic compliance (stretch fibers in the thoracic muscles), and pain. 1,2 Autonomic ventilation is increased by acidosis, PaO2 < 55 mmHg, PaCO2 ≥ 75 mmHg, hypotension, and pain.…”

“…1,2 These nuclei receive and integrate input regarding serum pH (chemoreceptors in the brainstem, carotid artery, and aortic arch), cardiovascular demand (arterial baroreceptors), thoracic compliance (stretch fibers in the thoracic muscles), and pain. 1,2 Autonomic ventilation is increased by acidosis, PaO2 < 55 mmHg, PaCO2 ≥ 75 mmHg, hypotension, and pain. 1,2 Autonomic tachypnea (increased rate of ventilation) is triggered by stimulation of the vagus nerve (e.g.…”

“…1,2 Autonomic ventilation is increased by acidosis, PaO2 < 55 mmHg, PaCO2 ≥ 75 mmHg, hypotension, and pain. 1,2 Autonomic tachypnea (increased rate of ventilation) is triggered by stimulation of the vagus nerve (e.g. by irritation of J fibers during increased tidal ventilation, or C fibers by pulmonary inflammation or edema).…”

“…by irritation of J fibers during increased tidal ventilation, or C fibers by pulmonary inflammation or edema). 1,2 Voluntary control of breathing is modulated by the hypothalamus and typically increases in response to temperature and emotion. Voluntary control of breathing can supersede the autonomic controls (within limits).…”

“…Voluntary control of breathing can supersede the autonomic controls (within limits). 1,2 Hyperventilation is an increase in both depth and rate of ventilation that exceeds metabolic needs. Hyperventilation syndrome (HVS) is a term used to describe the diverse set of symptoms associated with these respiratory increases and their subsequent alkalosis.…”