Course Orientation and the Purpose of Respiration

This orientation lesson establishes what respiration is, why every cell depends on it, and how the respiratory system fits into whole-body physiology. Students distinguish breathing from gas exchange and cellular respiration, then learn how oxygen delivery and carbon dioxide removal support energy production, acid-base balance, and survival.

The lesson also previews the course structure without going deeply into later topics. Students leave with a practical mental map: air must move into the lungs, gases must cross the respiratory membrane, blood must transport those gases, and cells must use oxygen while producing carbon dioxide.