 Joints and their classification  bony joints  fibrous joints  cartilaginous joints  Synovial joints 7-1

 Arthrology = study of the joints  Kinesiology = study of musculoskeletal movement  Classified by freedom of movement  diarthrosis (freely movable)  amphiarthrosis (slightly movable)  synarthrosis (little or no movement)  Classified how adjacent bones are joined  fibrous, cartilaginous, bony or synovial 7-2

 Gap between two bones ossifies  frontal and mandibular bones in infants  cranial sutures in elderly  attachment of first rib and sternum  Can occur in either fibrous or cartilaginous joint 7-3

 Collagen fibers span the space between bones  sutures, gomphoses and syndesmoses 7-4

7-5  Immovable fibrous joints  bind skull bones together  Serrate - interlocking lines  coronal, sagittal and lambdoid sutures  Lap - overlapping beveled edges  temporal and parietal bones  Plane - straight, nonoverlapping edges  palatine processes of the maxillae

 Attachment of a tooth to its socket  Held in place by fibrous periodontal ligament  collagen fibers attach tooth to jawbone  Some movement while chewing 7-6

 Two bones bound by ligament only  interosseus membrane  Most movable of fibrous joints  Interosseus membranes unite radius to ulna and tibia to fibula 7-7

 Bones are joined by hyaline cartilage  rib attachment to sternum  epiphyseal plate in children binds epiphysis and diaphysis 7-8

 2 bones joined by fibrocartilage  pubic symphysis and intervertebral discs  Only slight amount of movement is possible 7-9

Joint in which two bones are separated by a space called a joint cavity Most are freely movable 7-10

7-11  Articular capsule encloses joint cavity  continuous with periosteum  lined by synovial membrane  Synovial fluid = slippery fluid; feeds cartilages  Articular cartilage = hyaline cartilage covering the joint surfaces  Articular discs and menisci  jaw, wrist, sternoclavicular and knee joints  absorbs shock, guides bone movements and distributes forces  Tendon attaches muscle to bone  Ligament attaches bone to bone

 Bursa = saclike extension of joint capsule  between nearby structures so slide more easily past each other  Tendon sheaths = cylinders of connective tissue lined with synovial membrane and wrapped around a tendon 7-12

 Degrees through which a joint can move  Determined by  structure of the articular surfaces  strength and tautness of ligaments, tendons and capsule  stretching of ligaments increases range of motion  double-jointed people have long or slack ligaments  action of the muscles and tendons  nervous system monitors joint position and muscle tone 7-13

7-14