General Certificate of Secondary Education (GCSE) Physical Education (PE) Practice Exam 2026 - Free GCSE PE Practice Questions and Study Guide

Gaseous exchange refers to the process by which oxygen is transferred into the bloodstream and carbon dioxide is removed from the bloodstream. This occurs primarily in the alveoli of the lungs, where oxygen from inhaled air passes through the thin walls of the alveoli and into the capillaries surrounding them. At the same time, carbon dioxide, which is a waste product of cellular respiration, moves from the blood into the alveoli to be exhaled. This process is essential for maintaining the body's metabolism and ensuring that cells receive the oxygen they need to produce energy while also removing potentially harmful carbon dioxide. The opportunity for this exchange is critical for respiratory health and overall physiological balance.