The signal to the rest of the body that cells have been damaged is produced by which mechanism?

The signal to the rest of the body that cells have been damaged is produced by which mechanism?

• A. Chemical mediation
• B. Hemodynamic changes
• C. Phagocytosis
• D. Leukocyte migration

Answer: (A)

When tissue is damaged, signaling to the rest of the body comes from chemical mediators released by damaged cells and surrounding tissue. These mediators—histamine, bradykinin, prostaglandins, cytokines, and others—travel to blood vessels and immune cells to alert and coordinate the inflammatory response. This chemical signaling sets off vasodilation, vascular permeability, and recruitment of immune cells, effectively telling the body that injury has occurred. Phagocytosis describes the cleanup process by engulfing debris and pathogens, and leukocyte migration is the movement of immune cells toward the site driven by chemotactic signals—both are parts of the response rather than the primary way the injury signal is produced. Hemodynamic changes refer to the vascular changes that follow the initial signaling, not the signaling itself.

When tissue is damaged, signaling to the rest of the body comes from chemical mediators released by damaged cells and surrounding tissue. These mediators—histamine, bradykinin, prostaglandins, cytokines, and others—travel to blood vessels and immune cells to alert and coordinate the inflammatory response. This chemical signaling sets off vasodilation, vascular permeability, and recruitment of immune cells, effectively telling the body that injury has occurred.

Phagocytosis describes the cleanup process by engulfing debris and pathogens, and leukocyte migration is the movement of immune cells toward the site driven by chemotactic signals—both are parts of the response rather than the primary way the injury signal is produced. Hemodynamic changes refer to the vascular changes that follow the initial signaling, not the signaling itself.