Joints

Define joint

Any place where adjacent bone/s and cartilage come together to form a connection

How are joints classified

Structure = presence or absence of a cavity between articulating bones and type of ct

Functionality = range of movement available at the joint

Define fibrous joints

No joint cavity, bones held together by dense, irregular ct

Fibrous suture joint

Bones held together by layer of dense, irregular ct, only in skull

Fibrous stenosis joint

Complete fusion of two bones into one

Fibrous gomphosis

Ligament holding a tooth in jaw socket

Fibrous syndesmosis

Bones held together by long fibures, between radius and ulna/tibia and fibula, greater distance between articulating surfaces

Define cartilaginous joints

No joint cavity, bones connected by hyaline/articular cartilage or fibrocartilage

Primary/synchondrosis joint

Connected by hyaline cartilage - epiphyseal plate

Secondary/symphysis joint

Connected by pad of fibrocartilage between bones - pubic symphysis and intervertebral discs

Define synovial joints

Joint cavity between articulating bones, held together by joint capsule and ligaments

Define joint capsule

Inner synovial membrane and outer fibrous layer continuous with periosteum that encloses the cavity

Functions of synovial fluid

Reduce friction and shock, removes waste, supplies oxygen to chondrocytes, contains phagocytic cells to remove debris

Define joint cavity

Space for bones to articulate

Define meniscus

Pads of fibrocartilage between articulating bones to reduce friction and shock absorption

Define bursa

Enclosed sacs with potential space filled with a small amount of synovial fluid to reduce friction when surfaces move across each other

Three functional classifications of synovial joints

Synarthrosis - immoveable, amphiarthrosis = slightly moveable, diarthrosis = freely moveable

Define gliding joint movements

Sliding back and forth between nearly flat bone surfaces

Define angular joint movements

Increase or decrease in angle between articulating bones - flexion, extension, abduction, adduction, lateral flexion, hyperextension, circumduction

Define rotational joint movements

Bone revolves around its own longitudinal axis

Name specific joint movements

Elevation, depression, protraction, retraction, inversion, eversion, dorsiflexion, plantarflexion, supination, pronation, opposition