Gas exchange between the blood and body tissues is described as what?

Gas exchange between the blood and body tissues is described as what?

• A. Ventilation
• B. Diffusion
• C. Respiration
• D. Perfusion

Answer: (C)

Gas exchange between the blood and body tissues is described as respiration, specifically internal respiration. This refers to the transfer of gases between the circulating blood and tissue cells. The exchange happens by diffusion across capillary walls: oxygen moves from blood (where its partial pressure is higher) into the tissues (where it’s lower), and carbon dioxide moves from tissues (where its partial pressure is higher) into the blood (where it’s lower) to be carried back to the lungs. Perfusion ensures there is enough blood flow to sustain this exchange, while ventilation relates to moving air in and out of the lungs, a separate step. Diffusion explains the mechanism, but the process is termed respiration in this tissue-exchange context.

Gas exchange between the blood and body tissues is described as respiration, specifically internal respiration. This refers to the transfer of gases between the circulating blood and tissue cells. The exchange happens by diffusion across capillary walls: oxygen moves from blood (where its partial pressure is higher) into the tissues (where it’s lower), and carbon dioxide moves from tissues (where its partial pressure is higher) into the blood (where it’s lower) to be carried back to the lungs. Perfusion ensures there is enough blood flow to sustain this exchange, while ventilation relates to moving air in and out of the lungs, a separate step. Diffusion explains the mechanism, but the process is termed respiration in this tissue-exchange context.