Joints of the Skeletal System

Joints of the Skeletal System Chapter 8 p. 260 – p. 283

Joints • Also known as articulations • Join bones together • Allow movement

Classification of Joints • Type of Tissue: • Fibrous • Cartilaginous • Synovial • Movement: • Synarthrotic (immovable) • Amphiarthrotic (slightly movable) • Diarthrotic (freely movable)

Fibrous Joints • Syndesmosis • Sheet of connective tissue • Amphiarthrotic • Suture • Dense connective tissue between flat bones • Synarthrotic • Gomphosis • Cone shaped bony process in a bony socket • Teeth • Synarthrotic

Cartilaginous Joints • Synchondrosis • Hyaline cartilage • Usually temporary (long bone growth plates) • synarthrotic • Symphysis • Intervertebral discs, pelvis (between pubis bones) • Amphiarthrotic

Synovial Joints • Most joints • Diarthrotic • Made of: • Articular cartilage • Joint capsule • Synovial membrane (secretes synovial fluid)

Additions to Some Synovial Joints • Meniscus (menisci) • Disc of fibrocartilage within the joint • Bursae • Fluid filled sacs between the skin and a bone • Filled with synovial fluid

Types of Synovial Joints • Ball and socket (spheroidal) • Condylar (ellipsoidal) • Plane (gliding) • Hinge • Pivot (trichoid) • Saddle (sellar)

Ball and socket (spheroidal) • Wide range of motion • Movement in all planes • Shoulder and hip joints

Condylar (ellipsoidal) Plane (gliding) Sliding, twisting movement Wrist and ankle bones • Movement in different planes • NO rotational movement • Between metacarpals and phalanges

Hinge • Movement in one plane • Elbow and knee

Pivot (trichoid) • Rotation around a central axis only • Atlas / Axis movement

Saddle (sellar) • Articulated joints have convex and concave portions • Movement in 2 planes • Carpal and metacarpal of the thumb

Types of joint movement • Flexion • Extension • Hyperextension • Abduction • Adduction • Rotation

What connects these bones? • Bone to bone connection – ligaments • Bone to muscle connection – tendons

Knee joint ligaments

Joints of the Skeletal System