NSE 13A/B Lecture Notes - Lecture 2: Synovial Joint, Human Musculoskeletal System, Synovial Fluid
Document Summary
The musculo-skeletal system consists of the body"s bones, joints, and muscles. Humans need this system for support to stand erect and for movement. The joint (or articulation) is the place of union of two or more bones. Synovial joints are freely movable because the bones are separated from each other and enclosed in a joint cavity. This cavity is filled with a lubricant: synovial fluid that allows sliding of opposing surfaces, which enables movement. In synovial joints, a layer of resilient cartilage covers the surface of opposing bones. Cartilage is avascular, receiving nourishment from synovial fluid that circulates during joint movement. Cartilage cushions the bones and provides a smooth surface to facilitate movement. Each joint is surrounded by a fibrous capsule and is supported by ligaments. Ligaments are fibrous bands running directly from one bone to another that strengthen the joint and help prevent movement in undesirable directions. Skeletal voluntary, muscles, which are under conscious control.
