Ch. 9 Joints Flashcards
Amphiarthrosis
slightly movable joint
Diarthrosis
freely moveable joint; these come in a variety of shapes and several different types of movement
- synovial joints
Fiborous Joints
joints formed by a solid mass of connective tissue between neighbouring joints; have connective tissue masses of dense irregular connective tissue
- immovable or only slightly movable
- no joint cavity (synovial fluid)
- sutures, syndesmoses, interosseous membrane
Synovial Joints
- freely moveable articulations
- joints the incorporate a lubricated cavity called a synovial cavity that is surrounded by a connective tissue capsule that connects articulating bones
- slightly moveable to the most mobile joints of the body
- ex. carpal bones and shoulder joint
Ligaments
- dense irregular or regular connective tissue that bind one bone to another bone
- intrinsic binding structures within joint or as extrinsic supporting bands that stabilize joints while limiting range of motion
- ex. sutural or periodontal ligaments
Sutures
- fibrous joint composed of a thin layer of dense irregular tissue called sutural ligament, binds bones together
- between bones of the skull
- immovable or slightly movable in infants and children
- important role in growth and shock absorption in the skull
Syndesmoses (gomphosis)
- found between the proximal and distal ends of leg bones, and between teeth and alveolar process (gum)
- fibrous joint in which there is a greater distance between the articulating surfaces and more dense irregular connective tissue than suture
- arranged as a bundle (Interosseous ligament) and joint permits limited movement
Interosseous Membranes
- fibrous joints and is a substantial sheet of dense irregular tissue that binds neighbouring long bones and permits slight movement
- occur between the radius and the ulna in forearm and between the tibia and fibula of the leg
- help hold adjacent bones together and define the range of motion between the neighbouring bones and provide increased attachment surface for muscles and provide movements of the digits
Cartilaginous Joints
- solid connective tissue that allows little or no movement (synarthroses)
- articulating bones are tightly connected, either by hyaline or by fibrocartilage
- lack joint cavity
- 2 types (synchondroses and symphyses)
Synchondroses
- is immovable, cartilaginous joint in which connecting material is hyaline cartilage
- found between epiphysis and diaphysis of growing bones
- temporary; upon completion of bone growth, these joints ossify
- ex. epiphyseal plate; when bone stopes growing in length, bone replaces the hyaline cartilage, and the synchondrosis becomes a synostosis or bony joint
Symphasis
- cartilaginous joint in which the ends of the articulating bones are cover with hyaline cartilage, but the bones are connected by a broad, flat disc of fibrocartilage
- symphasis pubis and manubrium and sternum (midline of body)
- helps provide the limited range of motion in the vertebral column while serving as an important shock-absorbing pad between vertebral bodies
Articular Cartilage
- cover bone surface within the capsule of a synovial joint covered by hyaline cartilage
- covers the articulating surfaces of the bones but does not bind them together
- reduces friction between bones in the joint during movement and helps absorb shock
Articular (joint) capsule
- surrounds a synovial joint, encloses the synovial cavity, and unites the articulating bones
- composed of two layers, outer fibrous membrane and an inner synovial membrane
Fibrous Membrane
- consists of dense irregular connective tissue that attaches to the periosteum of the articulating bones; it is literally a thickened continuation of the periosteum between the two bones
- permits movement at a joint, and its great tensile strength help prevents bones from dislocating
Synovial Membrane
- inner layer of the articular capsule
- composed of thin arrangement of synovial cells on the surface and areolar connective tissue with elastic Fibers beneath
- includes accumulations of adipose tissue; thicker regions are called articular fat pads
Synovial Fluid
- secreted from synovial membrane which forms a thin film over the surfaces within the articular capsule
- consists of hyaluronic acid secreted by the synovial cells in the synovial membrane and interstitial fluid filtered from blood plasma
- reduces friction by lubricating joint and absorbing shock, also supplies oxygen and nutrients to the chondrocytes within articular cartilage
Synovial Joint Structure
Articular Capsule: surrounds a synovial joint
Articular Cartilage: covers end of the bone at joint
Synovial Membrane: covers synovial joint
Synovial Fluid: facilitates lubrication
Ligament: attached bones at joint
Joint Cavity: secrete synovial fluid
Synarthrosis
immovable joint
- fibrous and cartilaginous
Bursae
- fluid-filled saclike structures designed to reduce friction between adjacent tissues which can create considerable friction
- ex. synovial joints
Tendon (synovial) Sheaths
- tubular-shaped bursae