Final answer:
The four main characteristics of inflammation are redness, heat, swelling, and pain. These signs are due to increased blood flow, fluid accumulation, and the chemical response of the body's immune system to injury or infection.
Step-by-step explanation:
Inflammation is a basic innate immune response that 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. This helps isolate the foreign substance from further contact with body tissues.
The four main characteristics of inflammation are redness, heat (warmth), swelling (edema), and pain. These are the body's mechanisms to initiate the healing process. Redness and heat are caused by increased blood flow to the area. Swelling is the result of fluid accumulation, and pain is due to the release of chemicals that stimulate nerve endings.
While fever can occur as a systemic response to infection, it is not a direct localized characteristic of inflammation. Similarly, antibody production and sepsis are related to the immune response but are not localized signs of inflammation. Thus, the correct answer that describes the four main characteristics of inflammation is: D. redness, heat, swelling, and pain. It's important to note that a fifth characteristic can be loss of function, which sometimes accompanies the inflammatory response.