Final answer:
The phase of wound healing that occurs immediately after injury and lasts for 3-5 days is the inflammatory phase, characterized by redness, warmth, swelling, and pain.
Step-by-step explanation:
The phase of wound healing that occurs at the time of injury and lasts about 3-5 days is known as the inflammatory phase. After the initial formation of a blood clot to stop bleeding, the body transitions into the inflammatory response. This response is characterized by redness, swelling, warmth, and pain at the site of injury due to the release of inflammatory chemicals. During this phase, white blood cells enter the injured area to start cleaning up debris and fending off possible infections, setting the stage for the next phase of healing.