Final answer:
The normal adult respiration rate at rest is typically between 12 to 18 breaths per minute, which is option a) 12-16 breaths. This rate is regulated by the brain's medulla oblongata and ensures effective alveolar ventilation for gas exchange in the lungs.
Step-by-step explanation:
The question "What is considered a normal adult respiration per minute?" relates to the average number of breaths an adult takes in a minute. The correct answer is option a) 12-16 breaths. Breathing is an involuntary action, however, it can be consciously controlled in certain situations. The normal respiratory rate for a healthy adult at rest ranges from 12 to 18 breaths per minute. This rate is sufficient for maintaining effective alveolar ventilation, which prevents carbon dioxide buildup in the alveoli of the lungs.
From infancy to adulthood, the respiratory rate changes; a child under 1 year old normally breathes between 30 and 60 breaths per minute, which decreases to 18 to 30 breaths per minute by around 10 years of age. During adolescence, the rate slows further to match the adult normal rate. Breathing not only involves the intake of oxygen but also the expulsion of carbon dioxide, a by-product of metabolism. The medulla oblongata in the brain regulates the respiratory rate in response to the level of carbon dioxide, oxygen, and pH in the blood.