What happens during inhalation?

During inhalation, the primary action is that the lungs expand, which allows them to draw in air from the environment. This process occurs due to the diaphragm contracting and moving downward, as well as the intercostal muscles contracting to lift the rib cage. As the volume of the thoracic cavity increases, a negative pressure is created inside the lungs, causing air to flow in.

When air enters the lungs, oxygen is one of the main components of this air. The oxygen then diffuses across the thin walls of the alveoli (the tiny air sacs in the lungs) and into the bloodstream. This is essential for cellular respiration, as oxygen is delivered to the body's tissues to support metabolic processes. The process of gas exchange is a crucial function of the respiratory system, highlighting the importance of the expansion of the lungs during inhalation for both air intake and oxygen diffusion.

Other options do not accurately describe the inhalation process: the lungs do not expel air during inhalation; they expand instead. While blood pressure changes may occur due to various physiological responses, it's not a direct result of inhalation. Similarly, heart rate may vary in response to different activities but is not specifically slowed during inhalation. The focus of inhalation is primarily on