Final answer:
Inflammation decreases and tissue healing usually begins within 24 hours after injury.
Step-by-step explanation:
Inflammation typically decreases and tissue healing usually begins within 24 hours after injury. When the body is injured, it initiates an inflammatory response as a protective mechanism. This response includes several steps, such as vasodilation, fluid leakage, and the release of inflammatory mediators. After this acute phase, the body begins the repair and regeneration process to heal the damaged tissue.