Final answer:
Infants have a respiratory rate between 30-60 breaths per minute, which decreases as they grow older. By school age, the rate is about 18-30 breaths per minute, and adolescents have rates similar to adults, 12-18 breaths per minute.
Step-by-step explanation:
Infants (children under 1 year of age) have a normal respiratory rate that ranges between 30 and 60 breaths per minute. As they grow into toddlers (children ages 1 to 3), and then preschoolers (children ages 3 to 5), their respiratory rates typically decrease. Young school-age children, around 6 to 12 years old, tend to have respiratory rates ranging from 18 to 30 breaths per minute. By the time they reach adolescence (ages 13 to 18), the respiratory rate generally slows further to match adult rates, averaging 12 to 18 breaths per minute.
The respiratory rates are important indicators of health and can vary with physical exertion, emotional state, and health status. Respiratory centers located within the medulla oblongata in the brain control these rates and respond to changes in carbon dioxide, oxygen, and pH levels in the blood.