The passage of fluid to an organ or tissue is called which of the following?

• A. Circulation
• B. Diffusion
• C. Perfusion
• D. Osmosis

Answer: (C)

Perfusion describes the delivery of fluid, typically blood, to the tissues of an organ or body part. It focuses on the flow through the vessels to supply oxygen and nutrients and remove waste, which is what keeps the tissue alive and functioning. This makes it the best fit for the idea of fluid reaching a specific tissue or organ.

Circulation refers to the overall movement of blood through the heart and vessels as a system, not just delivery to a single tissue. Diffusion is the passive spread of particles from higher to lower concentration across a membrane, not about fluid moving through vessels to tissues. Osmosis is the diffusion of water across a semipermeable membrane, not about blood flow to tissues.