Browse the corpus

The largest organ of the human body is the skin. This organ comprises the epidermis, dermis, and hypodermis, which have additional layers categorized by the structures and characteristics of each layer. Below the skin lie muscles, ligaments, tendons, soft tissue, and bone. Bursa, and bursas or bursae for the plural form, is an important lubricated fluid-filled thin sac located between bone and surrounding soft tissue, bones and tendons, and/or muscles around joints, and are useful to the human body by reducing tension and negative effects of wear-and-tear at points of friction and provide resistance-free movement by the human body.[1] The bursa sac is lined by a synovial membrane or synovium, which contains the synovial fluid comparable to the consistency of raw egg whites. The sac is semi-permeable and allows certain materials to flow in and out of its membrane; when an injury to the bursa, fluid, such as blood, can fill the sac and irritate it. All 160 bursae that are present within the adult body vary in size and shape depending on the person and the location of the bursa; some bursae are not present at birth and develop as friction increases with age.[2] Bursae are classified as superficial when their structure lies between bones, tendons, or skin and deep when they’re between bones and muscles.[3] See Image. Hand Bursae.