Joints Flashcards

Flashcards about Joints from Anatomy and Physiology lecture notes

Joints functions

Skeleton mobility and structural cohesion

Classification of Joints (by structure)

Fibrous, Cartilaginous, Synovial

Classification of Joints (by function)

Synarthroses (immovable), Amphiarthroses (little movement), Diarthroses (very mobile)

Fibrous Joints

Bound by collagen fibers of connective tissue, no joint cavity, limited movement

Sutures (synostoses)

Between skull bones, very little connective tissue, interlocked bone, no movement, forms after birth

Syndesmoses

Bones connected by ligaments, movement depends on fiber length

Gomphoses

Peg-in-socket fibrous joint, tooth in alveolar socket attached by periodontal ligament

Cartilaginous Joints

Articulating bones bound by cartilage, no joint cavity, very little movement

Synchondroses

Bones bound by hyaline cartilage, virtually immovable

Symphyses

Bones bound by fibrocartilage, hyaline cartilage over bone surface, joint compressible and resilient, limited movement

Synovial Joints

Articulating surfaces separated by fluid in a joint cavity, substantial freedom of movement

Articular Cartilage

Thin hyaline cartilage covering opposing bone surfaces, absorbs compression forces, prevents bone crushing

Joint (articular) cavity

Potential space containing synovial liquid

Articular capsule

Two-layered membrane enclosing the joint: external fibrous layer and synovial membrane

External fibrous layer

Dense irregular connective tissue, continuous with periosteum, prevents bones being pulled apart

Synovial membrane

Connective tissue, lines internal surfaces, secretes synovial fluid

Synovial liquid

Fills synovial cavity, slippery hyaluronic acid-rich liquid, lubricates and nourishes cartilage

Reinforcing ligaments

Band-like ligaments, intra- or extracapsular, reinforce joint integrity

Nerves (in joints)

On the capsule, for pain, joint position, and stretch

Blood vessels (in joints)

Supply the synovial membrane for synovial liquid production

Fatty pads

Between fibrous and synovial membranes, for cushioning

Articular disks (menisci)

Partially divide synovial cavity, for joint stabilization

Bursae

Flattened fibrous sacs full of synovial fluid, decrease friction

Factors affecting stability of Synovial Joints

Shape of articular surface, ligaments, and muscle tone

Muscle origin

Point where muscle attaches to an immobile bone

Muscle insertion

Point where muscle attaches to a mobile bone

Plane joint

Flat articular surfaces, surfaces slip over each other (nonaxial)

Hinge joint

Cylinder and trough surfaces, flexion and extension movements (uniaxial)

Pivot joint

Sleeve and axle surfaces, rotation on bone axis (uniaxial)

Condylar joint

Oval articular surfaces, flexion and extension, adduction and abduction (biaxial)

Saddle joint

Concave and convex articular surfaces, flexion and extension, adduction and abduction (biaxial)

Ball and socket joint

Cup (socket) and spherical head (ball) articular surfaces, flexion and extension, adduction and abduction and rotation (multiaxial)

Gliding movement

Flat bone surfaces slip over each other, no appreciable angulation or rotation

Angular movements

Increment or decrement in the angle between two bones

Flexion

Decreases the angle of a joint

Extension

Increases the angle between the articulating bones

Hyperextension

Extension that goes beyond the anatomical position

Abduction

Movement of a limb away from the midline

Adduction

Movement of a limb toward the midline

Circumduction

Moving a limb describing a cone in the space

Rotation

Turning a bone around its own long axis

Supination

Radius and ulna parallel, palm face anteriorly

Pronation

Radius and ulna crossed, palm face posteriorly

Dorsiflexion

Lifting the foot toward the shin

Plantar flexion

Depressing the foot

Inversion

Sole of the foot points medially

Eversion

Sole of the foot points laterally

Protraction

Non-angular movement in an anterior direction

Retraction

Non-angular movement in a posterior direction

Elevation

Movement in superior direction

Depression

Movement in inferior direction

Opposition

Touching the tip of the thumb with the tip of the other fingers