A patient has sprained her knee in a game of basketball and presents with swelling and pain. Which of the following statements best describes why the swelling occurs?
A) Leukotrienes make blood vessels more permeable, leading to the delivery of immune system cells to the damaged tissue.
B) Broken blood vessels bleed into the injured area, making it swell.
C) The increase in temperature by prostaglandins results in increased blood flow to the area.
D) Thromboxanes isolate the injured tissue, resulting in swelling.
E) All of the above

Question

Quizplus · Accepted Answer

When tissue is damaged, it releases leukotrienes which make blood vessels more permeable. This allows immune system cells to enter the area and fight off any potential infections. The increased permeability also results in the accumulation of fluid in the area, leading to swelling. Broken blood vessels (choice B) may contribute to swelling, but they alone do not explain the mechanism of swelling in this scenario. Prostaglandins (choice C) do increase blood flow to the area, but this does not directly result in swelling. Thromboxanes (choice D) actually work to constrict blood vessels and prevent bleeding, so they are not involved in the mechanism of swelling here. Therefore, choice A is the best choice.

A Patient Has Sprained Her Knee in a Game of Basketball