Infiltration is best described as

• A. The movement of blood into tissue
• B. The process of tissue repair
• C. The process by which substance passes into and is deposited within tissue
• D. A condition of tissue swelling

Answer: (C)

Infiltration describes how a substance passes into and is deposited within tissue. This means the substance moves from outside the tissue into the tissue itself and becomes incorporated there, rather than simply circulating in the blood, undergoing healing, or causing swelling.

This is different from the movement of blood into tissue (perfusion), the process of tissue repair (healing), or a condition characterized by tissue swelling (edema). For example, when a medication is injected into tissue or a dye is introduced for imaging, the substance infiltrates the tissue, fitting the description for how infiltration is defined.