Classification of Joints

Vocabulary flashcards on joint classification, types, structures, and nerve supply based on medical lecture notes.

Joint

The contact between two or more bones.

Fibrous Joints

Fixed joints in which the surfaces of bones are connected together by fibrous tissue, with no joint cavity and very limited or no movement.

Sutures

Fibrous joints present in the skull where contact occurs between 2 margins of bones connected by sutural ligament; they become obliterated in old age.

Gomphosis

A fibrous joint where the roots of teeth are connected to their sockets in the mandible and maxilla by periodontal ligament.

Syndesmosis

A fibrous joint where contact between 2 surfaces of bones is connected by an interosseous ligament, such as at the inferior tibio-fibular joint.

Cartilaginous Joints

Joints where the surfaces of articulating bones are connected together by cartilaginous tissue, with no joint cavity and very limited or no movement.

Primary Cartilaginous Joint

A temporary cartilaginous joint where hyaline cartilage directly unites articulating bones, undergoing ossification and allowing no movement (e.g., epiphyseal plate of cartilage, first rib and manubrium).

Secondary Cartilaginous Joint

A permanent cartilaginous joint located in the midline of the body where bone surfaces covered with hyaline cartilage are separated by a layer of white fibro-cartilage, allowing limited movements (e.g., intervertebral disc, symphysis pubis).

Synovial Joints

Freely mobile joints present in the limbs, characterized by a strong fibrous capsule, articular hyaline cartilage covering bone surfaces, a joint cavity containing synovial fluid, and a lining synovial membrane.

Fibrous Capsule

A strong capsule that completely surrounds a synovial joint and is supported and strengthened by strong ligaments.

Articular Cartilage

Hyaline cartilage that covers the articular surface of bones within a synovial joint.

Synovial Membrane

A membrane lining a synovial joint cavity that secretes and absorbs synovial fluid.

Hinge Joint

A uni-axial synovial joint permitting movement around one axis, such as the elbow joint and ankle joint.

Pivot Joint

A uni-axial synovial joint allowing rotational movement around a single axis, such as the superior radio-ulnar joint between the head of the radius and radial notch of the ulna.

Condylar Joint

A bi-axial synovial joint featuring condyles, such as the temporomandibular joint and knee joint.

Ellipsoid Joint

A bi-axial synovial joint such as the wrist joint, which can also be considered a condyloid joint in respect to movement.

Saddle Joint

A bi-axial synovial joint where opposing articular surfaces are each concave-convex, such as the carpo-metacarpal joint of the thumb.

Ball and Socket Joint

A multiaxial (poly-axial) synovial joint where a spherical bone head fits into a cuplike socket, allowing motion in multiple axes (e.g., hip joint, shoulder joint).

Plane Joint

A non-axial synovial joint where articular surfaces are flat and movement consists of gliding without any axis of movement (e.g., intervertebral joints).

Hilton's Law

The law stating that the nerve supply of a joint comes from nerves that supply the muscles which act over that joint.

Articular Nerves

Sensory nerves supplying a joint that end in the capsule and ligaments and are sensitive to pain, position, and movements.

Factors Affecting Stability

The four main factors determining joint stability: 1) Shape & fitting of surfaces, 2) Thickness & elasticity of capsule, 3) Ligaments, and 4) Surrounding muscles.

Limitation of Movements

The four primary factors limiting joint movement: 1) Tension of ligaments, 2) Tension of antagonist muscles, 3) Approximation of soft parts, and 4) Shape of articulating bones.