Mary, 21 years old, presented to the hospital emergency department with an infected laceration on her left foot.

1. Mary, 21 years old, presented to the hospital emergency department with an infected laceration on her left foot. Mary was at a beach resort four days ago, when she trod on a broken glass bottle and sustained a deep 2 cm long jagged laceration over the lateral aspect of her left foot. She used her handkerchief to bandage the wound. This morning the wound was extremely painful, swollen and had a purulent discharge.
2. On inspection of the wound the following wound observations were made:
3. - Painful and swollen,
4. - Red and warm when touched. - Purulent discharge.

what is the Physiological basis of the wound observations