Injury

Injury is physiological damage to an organism. The response to injury, whether in humans, in other animals, in plants, in fungi, or in single-celled eukaryotes such as choanoflagellates, is substantially shared, implying that the mechanisms are ancient.

Injuries can be caused in many ways, including mechanical trauma, toxins, interactions with other organisms, or abiotic factors in the environment. In many animal taxa, injury prompts an inflammatory response that initiates wound healing. In both plants and animals, substances are released to help occlude the wound, limiting fluid loss and the entry of pathogens. Many organisms secrete antimicrobial chemicals, which limit wound infection; animals have immune responses for the same purpose. Both plants and animals have mechanisms of regrowth that may result in complete or partial healing of the injury.