Types of Joints in Human Anatomy

Study Notes

Joints are where two or more bones meet. Movement between bones may or may not occur at a joint.
Joints are categorized based on the tissue type connecting bones.

Synovial Joints: These joints have a fluid-filled space (synovial cavity) between articulating bones. Characterized by a smooth surface, which allows for free movement.
- Hinge: Uniaxial movement (e.g., elbow, knee).
- Ball and Socket: Multiaxial movement (e.g., shoulder, hip).
- Pivot: Uniaxial movement (e.g., in the neck).
- Ellipsoid: Biaxial movement (e.g., wrist).
- Saddle: Biaxial movement (e.g., thumb).
- Gliding: Uniaxial movement between flat bones (e.g., wrist, ankle).
Fibrous Joints: Bones are connected by fibrous connective tissue. Often immovable or only slightly movable.
- Sutures: Found only in the skull, joining skull bones with a thin layer of connective tissue.
- Gomphoses: Connect teeth to their sockets. Short collagen fibers hold teeth in sockets.
- Syndesmoses: Bones are connected by ligaments (e.g., the ligamentum flavum).
Cartilaginous Joints: Bones are connected by cartilage. Allow limited movement.
- Synchondroses: Found in developing bones, separated by hyaline cartilage (e.g., growth plates).
- Symphyses: Connected by fibrocartilage (e.g., pubic symphysis, intervertebral discs).

Joint cavity: The space between the articulating bones.
Articular cartilage: A smooth layer of cartilage covering the bone surfaces to reduce friction.
Articular capsule: A fibrous capsule that encloses the joint, providing support and stability. The capsule has an outer fibrous membrane and an inner synovial membrane.
Synovial fluid: A lubricating fluid within the joint cavity, reducing friction.
Accessory ligaments: Ligaments that support the joint beyond the capsule. Can be extra-capsular or intra-capsular.