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42 terms

Joints

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Arthrology
Study of joints and their structure, function, and non-function
Joint
Any point where two bones meet; named for bones involved; classified according to how adjacent bones are bound to each other; movement not required
Synostosis
Joint in which two bones, once separate, become fused by osseous tissue (i.e. frontal bone and epiphysis in adults)
Articulation
The point of connection between two bones or elements of a skeleton (especially if the articulation allows motion)
Bony Joints
Immovable joint formed when the gap between two bones ossifies and they become a single bone
Fibrous Joints
Type of joint where bones are connected by fibrous tissue (collagen); namely dense regular connective tissue; no joint cavity is present; most are immovable or only slight movable
Synarthrodial Joint
Type of joint in which bones are held together by tough connective tissue making the joint essentially immoveable (aka Fibrous Joint)
What are the three kinds of Fibrous Joints?
Sutures, Gomphosis, and Syndesmosis
Sutures
Immovable joints that unite cranial bones
Gomphosis
Bones fit together like a peg in a hole, secured by fibrous tissue (i.e. tooth & socket)
Syndesmosis
Connected by a ligament or membrane that allows some movement (radius and ulna or tibia and fibula)
Cartilaginous Joints
Have no joint cavity, Bones held together by cartilage. Examples are growth plates, disks between vertebrae and the pelvic symphysis; partial movement
What are the two types of Cartilaginous Joints?
Syncondroses and Symphyses
Syncondroses
Hyaline cartilage unites the bones. Immovable. Ex. between the ribs and sternum, growth plate between the diaphyses and epiphyses
Symphyses
Structurally cartilagenous joints with fibrocartilage, found in pubic symphysis (pregnancy) and intervertebral disc (Functionally amphiarthroses - slightly movable)
Synovial Joints
The classic joints, (stifle joint, elbow joint, fetlock joint)
Diarthrosis
Synonym for synovial joint
Synovial Cavity
Space between bones at a synovial joint; contains synovial fluid produced by the synovial membrane
Synovial Fluid
Viscid lubricating fluid secreted by the membrane lining joints and tendon sheaths etc.; removes waste, add to ease of mobility and nourishes joint
Joint Capsule
Surrounds the joint cavity, has the layers the fibrous capsule and the synovial membrane
Fibrous Capsule
Outer layer of joint capsule that is continuous with the periosteum; unites articular bones; encloses joint cavity
Synovial Membrane
A thin membrane in synovial (freely moving) joints that lines the point capsule and produces/secretes synovial fluid that is made of Hyaluronic acid
Areolar Connective Tissue
Gel-like matrix with all 3 fiber types; fibroblasts, mast cells, macrophages & some white blood cells
Meniscus
A disk of cartilage that serves as a cushion between the ends of bones that meet at a point (aka Articular Discs)
Fibrocartilage
Grows inward from joint capsule to form pad between articulating bones to absorb shock and pressure, guide bones in movement, and reduce chances of dislocation (i.e. pads between vertebrae that are shock absorbers)
Bursa
Sac-like connective structure found in some joints; protects moving parts from friction, cushions different adjacent structures (i.e. located between adjacent muscles, tendon passing over bone, and between bone and skin)
Tendons
Tough bands of connective tissue that attach muscles to bones; most important structure in stabilizing a joint
Ligaments
Fibrous tissue that connects bone to bone
Extracapsular Ligaments
Fibular and tibial collateral ligaments
Intracapsular Ligaments
Anterior and posterior cruciate ligaments
Collateral Ligaments
Connect the joint at both sides; they give medial and lateral stability and prevent dislocation
Cruciate Ligaments
Crisscross within the knee (forms an "X"); they give anterior and posterior stability and help control rotation
What are some types of synovial joints?
Planar, hinge, pivot, condylar, saddle, and ball and socket
Planar Joint
Side to side, gliding movement (i.e. joints that form between articular facets); a synovial joint having articulating surfaces that are flat or slightly curved, permitting side-to-side and back-and-forth movements; examples include the intercarpal and intertarsal joints; also called a gliding joint
Articular Facets
The smooth joint surfaces of the articular processes
Hinge Joint
Found at the elbow, knee, ankle, and fingers, allows a joint to bend and straighten promoting rotation; movement in one plane
Pivot Joint
Rotating bone turns around an axis; i.e. connection between radius/ulna and humerus
Condylar Joint
Biaxial joint capable of movement in 2 planes; oval convex csuface on one bone that fits in a complementary shaped depression on the other
Saddle Joint
Freely movable joint that allows movement of one bone to slide in two directions (i.e. thumb joint)
Arthroscopic Surgery
A type of surgery performed on a joint using only small punctureholes to insert instruments to observe and fix injured structures; inject saline
Arthroplasty
Surgical reconstruction or replacement of a malformed or degenerated joint
Kinesiologist
One who studies motion or movement