Short answers, pulled from the story.
Injury is a wound caused by an external source that triggers a universal physiological event across every kingdom of life. It serves as a defensive protocol to prevent death by sealing the breach to stop the loss of vital fluids and block the entry of bacteria.
The World Health Organization established its classification of injuries in humans on the 1st of January 1948. This system categorizes injuries by mechanism, objects, and place of occurrence to help medical professionals understand human intent and activity.
The body immediately initiates an inflammatory response that prompts the coagulation of blood or body fluid to stop the bleeding. This process summons resources to the site of damage to begin the healing process and mobilizes the immune system to clear out debris.
Mechanical damage from penetration by sharp objects like teeth or blunt force remains the most common form of injury. Other causes include attempted predation, territorial fights, falls from great heights, and abiotic factors such as lightning or freezing temperatures.
Organisms utilize coagulation to stop bleeding and secrete antimicrobial peptides to fight off infection following an injury. Some species like cnidaria can heal wounds in a matter of minutes, while arthropods repair injuries to their cuticle to some extent.