Chapter 8 Joints Flashcards
Joints Function
- Functional junctions between bones
- Bind parts of skeletal system together
- Make bone growth possible
- Permit parts of the skeleton to change shape during childbirth -Enable body to move in response to skeletal muscle contractions
Structural Classification of Joints
Fibrous
Cartilaginous
Synovial
Functional Classification of Joints:
Synarthrotic—immovable
Amphiarthrotic—slightly movable
Diarthrotic—freely movable
Synovial Joints
Most joints are synovial joints
All are diarthrotic joints
Structure of synovial joint
Articular cartilage covers articular ends of bones
Joint capsule, consists of 2 layers:
- Outer fibrous layer, composed of ligaments
- Inner layer, synovial membrane, which secretes synovial fluid
Fibrous joints
are held together with dense connective tissue containing many collagen fibers; found in bones in close contact (Tibia/Fibula, Radius/Ulna)
Cartilaginous joints
are connected by hyaline cartilage or fibrocartilage There are 2 types of cartilaginous joints
Ball-and-Socket Joint
Round head in cup-shaped cavity
Widest range of motion
Multiaxial, plus rotation Hip, shoulder
Condylar Joint
Oval condyle fits into elliptical cavity
Back-and-forth, side-to-side movement
Biaxial movement, no rotation
Joints between metacarpals & phalanges
Plane Joint
Also called gliding joint Almost flat, or slightly curved Back-and-forth and twisting
Nonaxial movement
Wrist and ankle joints
Hinge Joint
Convex surface fits into concave surface of other bone Uniaxial movement (in 1 plane)
Elbow, joints between phalanges
Pivot Joint
Cylindrical surface rotates within ring of other bone Uniaxial movement
Rotation only Atlas (C1) and dens of axis (C2)
Saddle Joint
Both bones have concave and convex surfaces
Biaxial movement (in 2 planes)
Carpal & metacarpal of thumb
Joint Movement
Movement at a joint occurs when a muscle contracts, and its fibers pull the insertion towards the origin
Relatively fixed end of a skeletal muscle is called the origin
More movable end of a skeletal muscle is called the insertion
Shoulder Joint Bones
Humerus
Scapulae (glenoid cavity)