Visualization of the Pulmonary system - It includes the lungs , the bronchial tree and the pulmonary vessels

For humans, the typical respiratory rate for a healthy adult at rest is 12–18 breaths per minute.The respiratory center sets the quiet respiratory rhythm at around two seconds for an inhalation and three seconds exhalation. This gives the lower of the average rate at 12 breaths per minute.

Average resting respiratory rates by age are

birth to 6 weeks: 30–40 breaths per minute 6 months: 25–40 breaths per minute 3 years: 20–30 breaths per minute 6 years: 18–25 breaths per minute 10 years: 17–23 breaths per minute Adults: 12-18 breaths per minute Elderly ≥ 65 years old: 12-28 breaths per minute Elderly ≥ 80 years old: 10-30 breaths per minute .