Which of the following is classified as a local response to infection?
Select all that apply..
A Heat
B Pain
C Redness
D Fever
E Swelling
The correct answer and explanation is:
The correct answers are A, B, C, and E: Heat, Pain, Redness, and Swelling.
These are considered local responses to infection. When the body experiences an infection, a localized immune response is triggered in the affected area. This response is part of the inflammatory process, which serves to fight off pathogens and promote healing.
- Heat: Increased blood flow to the site of infection can cause the area to become warm. This is a direct result of the body’s efforts to bring more immune cells to the area to fight the infection. The warmth also helps to inhibit the growth of pathogens, as many bacteria and viruses thrive at lower temperatures.
- Pain: Pain often occurs at the site of infection due to the release of chemicals like prostaglandins, which sensitize nerve endings. The inflammation also increases pressure in the tissues, which can irritate nerves and cause pain.
- Redness: The increased blood flow to the affected area is responsible for the redness. As blood vessels dilate in response to chemical signals from the immune system, the skin takes on a reddish hue, a hallmark of inflammation.
- Swelling: Swelling happens when fluid leaks out of blood vessels into the surrounding tissue. This is part of the inflammatory response and serves to dilute harmful substances and deliver immune cells to the infection site. The increased fluid volume leads to visible puffiness or swelling.
Fever (D), on the other hand, is not a local response. It is a systemic response, meaning it affects the entire body. Fever is triggered by chemicals called pyrogens, which are released by the immune system and reset the body’s thermostat in the brain to a higher temperature. This elevated temperature enhances the immune response and helps the body fight off infections more effectively.