CH.8

Joints

Articulations where two or more bones meet to hold the skeleton together and provide mobility.

Synarthroses

Immovable joints, primarily fibrous in nature.

Amphiarthroses

Slightly moveable joints.

Diarthroses

Freely movable joints, typically synovial.

Fibrous joints

Joints connected by collagen fibers, most are synarthrosis.

Gomphosis

Fibrous joint in which a tooth fits into a socket, held by a ligament.

Suture

Fibrous joint forming seams between cranial bones that may fuse and ossify in middle age.

Syndesmosis

Fibrous joint connected by ligaments, allowing slight movement.

Cartilaginous joints

Joints connected by cartilage, can be synchondroses or symphyses.

Synchondroses

Cartilaginous joints united by hyaline cartilage.

Symphyses

Cartilaginous joints united by fibrocartilage, offering strength.

Synovial joints

Fluid-filled joints that are freely movable (diarthrotic).

Articular cartilage

Avascular hyaline cartilage covering the surfaces of bones in synovial joints.

Joint cavity

Space containing a small amount of synovial fluid.

Synovial fluid

Slippery fluid in joint cavity, composed mainly of water and hyaluronic acid.

Articular capsule

Two-layer structure encapsulating synovial joints, with fibrous outer layer and synovial membrane inner layer.

Reinforcing ligaments

Ligaments that support and strengthen synovial joints, categorized as capsular, extracapsular, and intracapsular.

Burase

Bags of lubricant reducing friction between bones and ligaments.

Elongated bursae

Also called tendon sheaths, which help in reducing friction.

Factors influencing joint stability

Include articular surface shape, ligament number and location, and muscle tendons.

Origin

The point where a muscle attaches to an immovable bone.

Insertion

The point where a muscle attaches to a movable bone.

Nonaxial movement

Movement allowed by synovial joints that involves only slipping movements.

Uniaxial movement

Movement in one plane.

Biaxial movement

Movement in two planes.

Multiaxial movement

Movement in all three planes.

Gliding movement

Sliding movements in synovial joints.

Angular movements

Movements that increase or decrease the angle between two bones.

Extension

Increasing the angle between two bones.

Flexion

Decreasing the angle between two bones.

Abduction

Movement of a limb away from the midline.

Adduction

Movement of a limb towards the midline.

Circumduction

Movement that describes a cone shape in space.

Rotation

Turning movement of a bone around its own axis.

What are the three types of structural joints?

Fibrous joints, cartilaginous joints, and synovial joints.

What is a fibrous joint?

A joint connected by collagen fibers, most are synarthrosis.

What is a cartilaginous joint?

A joint connected by cartilage; can be synchondroses or symphyses.

What is a synovial joint?

A fluid-filled joint that is freely movable (diarthrotic).

What are the three types of functional joints?

Synarthroses, amphiarthroses, and diarthroses.

What is a synarthrosis?

An immovable joint, primarily fibrous in nature.

What is an amphiarthrosis?

A slightly moveable joint.

What is a diarthrosis?

A freely movable joint, typically synovial.