Final answer:
A joint is a place where adjacent bones or bone and cartilage come together. Joints are classified structurally based on the type of connective tissue or cartilage that holds the bones together, and functionally based on the degree of movement available between the bones. There are three structural classifications of joints: fibrous, cartilaginous, and synovial. The functional classifications include immobile joints, slightly moveable joints, and freely moveable joints.
Step-by-step explanation:
A joint, also called an articulation, is any place where adjacent bones or bone and cartilage come together (articulate with each other) to form a connection. Joints are classified both structurally and functionally. Structural classifications of joints take into account whether the adjacent bones are strongly anchored to each other by fibrous connective tissue or cartilage, or whether the adjacent bones articulate with each other within a fluid-filled space called a joint cavity.
Functional classifications describe the degree of movement available between the bones, ranging from immobile, to slightly mobile, to freely moveable joints. The amount of movement available at a particular joint of the body is related to the functional requirements for that joint. Thus immobile or slightly moveable joints serve to protect internal organs, give stability to the body, and allow for limited body movement. In contrast, freely moveable joints allow for much more extensive movements of the body and limbs.
Structural Classification of Joints
- Fibrous joints: Adjacent bones are united by fibrous connective tissue.
- Cartilaginous joints: The bones are joined by hyaline cartilage or fibrocartilage.
- Synovial joints: The articulating surfaces of the bones are not directly connected, but instead come into contact with each other within a joint cavity filled with a lubricating fluid.
Functional Classification of Joints
- Synarthrosis: Immobile joint
- Amphiarthrosis: Slightly moveable joint
- Diarthrosis: Freely moveable joint