Transcript Joints
JOINTS Joints and their classification bony joints fibrous joints cartilaginous joints Synovial joints 7-1 JOINTS AND THEIR CLASSIFICATION 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 BONY JOINT (SYNOSTOSIS) 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 FIBROUS JOINTS (SYNARTHROSIS) Collagen fibers span the space between bones sutures, gomphoses and syndesmoses 7-4 FIBROUS JOINT -- SUTURES 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 7-5 FIBROUS JOINT -- GOMPHOSES 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 FIBROUS JOINT -- SYNDESMOSIS 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 CARTILAGINOUS JOINT -- SYNCHONDROSIS Bones are joined by hyaline cartilage rib attachment to sternum epiphyseal plate in children binds epiphysis and diaphysis 7-8 CARTILAGINOUS JOINT -- SYMPHYSIS 2 bones joined by fibrocartilage pubic symphysis and intervertebral discs Only slight amount of movement is possible 7-9 SYNOVIAL JOINT Joint in which two bones are separated by a space called a joint cavity Most are freely movable 7-10 GENERAL ANATOMY Articular capsule encloses joint cavity Synovial fluid = slippery fluid; feeds cartilages Articular cartilage = hyaline cartilage covering the joint surfaces Articular discs and menisci continuous with periosteum lined by synovial membrane jaw, wrist, sternoclavicular and knee joints absorbs shock, guides bone movements and distributes forces Tendon attaches muscle to bone Ligament attaches bone to bone 7-11 TENDON SHEATHS AND BURSAE 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 RANGE OF MOTION 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 TYPES OF SYNOVIAL JOINTS 7-14