Bursins are small, fluid-filled sacs located in various parts of the body, primarily near joints. They serve to reduce friction between tissues, such as muscles, tendons, and bones, allowing for smooth movement. When bursins become inflamed, a condition known as bursitis can occur, leading to pain and discomfort. These structures are found in areas like the shoulders, elbows, and knees, where movement is frequent. Bursins play a crucial role in maintaining joint function and overall mobility. Understanding their function can help in recognizing and treating related issues, such as bursitis and other joint problems.