PATHOLOGY

Detailed explanation-1: -(b) Histamine increases blood flow to the wound site, and increased vascular permeability allows fluid, proteins, phagocytes, and other immune cells to enter infected tissue. These events result in the swelling and reddening of the injured site, and the increased blood flow to the injured site causes it to feel warm.

Detailed explanation-2: -Chemicals are released by granulocytes (e.g. histamines) which promote vasodilation around the damaged area. 3. More blood flow occurs to this area, and in the blood are cells and chemicals to help stop an infection from occurring. This increased blood flow results in redness, swelling and warmth around the area.

Detailed explanation-3: -When a pathogen invades a tissue, it almost always elicits an inflammatory response. This response is characterized by pain, redness, heat, and swelling at the site of infection, all caused by changes in local blood vessels.

Detailed explanation-4: -Redness and heat are caused by increased blood flow. Swelling is the result of the increased movement of fluid and white blood cells into the injured area. The release of chemicals and the compression of nerves in the area of injury cause pain.

Detailed explanation-5: -The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling.