Final answer:
The normal respiratory rate decreases with age from infancy to adulthood: 30-60 for infants, 18-30 for older children, and 12-18 for adolescents and adults, with neonates and newborns having rates similar to infants.
Step-by-step explanation:
Normal Breathing Rates
The normal respiratory rates vary with age, transitioning from infancy to adulthood. An infant under 1 year typically has a normal respiratory rate ranging from 30 to 60 breaths per minute. As children grow, the rate decreases. By about 10 years of age, a child's normal respiratory rate is closer to 18 to 30 breaths per minute. Entering adolescence, the rate further declines to approximate that of an adult, which is around 12 to 18 breaths per minute under non-exertion conditions. The newborn and neonate, within the first 28 days of life, also fall within the higher respiratory range similar to that of infants.
Breathing, a process primarily regulated within the ventilation control centers of the brain, is crucial as it affects alveolar ventilation and the overall gas exchange in the lungs. For adults, as an example, roughly 1 liter of air is inhaled with each breath under normal conditions. The respiratory rate, along with tidal volume, contributes to maintaining adequate alveolar ventilation by preventing carbon dioxide buildup and ensuring oxygen supply to meet metabolic demands.