Pump Up Your Fitness Career: Dominate the ISSA Trainer Exam 2026 – Train Like a Pro!

The primary responsibility of the respiratory system is supplying oxygen to the body. This system includes the lungs and airways, which work together to facilitate breathing. When we inhale, oxygen from the air enters the lungs and diffuses into the bloodstream, where it is then transported to cells throughout the body. Oxygen is critical for cellular respiration, the process by which cells generate energy.

In contrast, while regulating body temperature is an essential bodily function, it is primarily managed by the integumentary system (skin) and the blood circulatory system. Energy production occurs at the cellular level through metabolic processes, but it specifically requires oxygen supplied by the respiratory system. Lastly, nutrient storage is a function managed by the digestive system and various organs such as the liver, rather than the respiratory system. Thus, the role of the respiratory system in supplying oxygen is fundamental for sustaining life and facilitating other physiological processes.