Which term is defined as the exchange of oxygen and carbon dioxide between circulating blood and tissue cells?

Which term is defined as the exchange of oxygen and carbon dioxide between circulating blood and tissue cells?

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

Answer: (B)

Diffusion is the exchange of oxygen and carbon dioxide between circulating blood and tissue cells. This process occurs as gases move down their concentration or partial pressure gradients across the thin capillary and cell membranes. Oxygen moves from blood, where its partial pressure is higher, into tissue cells where it is used, while carbon dioxide, produced by tissues, moves from cells into the blood where its partial pressure is higher, allowing it to be carried away to be exhaled. Perfusion describes how well blood flows to the tissues, which affects how much gas is delivered and removed, but the actual exchange happens by diffusion across the capillary walls. Ventilation is about moving air into and out of the lungs to supply oxygen and remove carbon dioxide at the lung level, and eupnea means normal breathing.

Diffusion is the exchange of oxygen and carbon dioxide between circulating blood and tissue cells. This process occurs as gases move down their concentration or partial pressure gradients across the thin capillary and cell membranes. Oxygen moves from blood, where its partial pressure is higher, into tissue cells where it is used, while carbon dioxide, produced by tissues, moves from cells into the blood where its partial pressure is higher, allowing it to be carried away to be exhaled.

Perfusion describes how well blood flows to the tissues, which affects how much gas is delivered and removed, but the actual exchange happens by diffusion across the capillary walls. Ventilation is about moving air into and out of the lungs to supply oxygen and remove carbon dioxide at the lung level, and eupnea means normal breathing.