LAB 16: JOINTS

Joints

structures in the skeleton where two or more bones join together

Fibrous Joints

fibrous connective tissue tightly binds the articulation bones

Types of Fibrous Joints

suture, syndesmosis, gomphosis

Suture

joint between two flat bones

Syndesmosis

bands of fibrous tissue that bind bones

Gomphosis

fibrous membrane that connects each tooth to its socket in a jaw's alveolar process

Example of syndesmosis

between tibia and fibula

Cartilaginous Joints

formed when a mass of cartilage joins bones

Types of Cartilaginous Joints

synchondrosis, symphisis

Synchondrosis

hyaline cartilage that connects bones

Example of synchondrosis

costal cartilage connection between a rib and the sternum

Symphysis

fibrocartilage that forms the joint

Example of symphysis

symphysis pubis, joining left and right coxae, or between bodies of vertebrae

Synovial Joints

diarthrotic (freely moveable joints) composed of ligaments and other connective structures and lined with a lubricating synovial membrane

Types of Synovial Joints

gliding, hinge, ellipsoid (condyloid), pivot, saddle, ball-and-socket

Gliding

two flat surfaces that slide past eachother

Example of gliding

between two carpal bones

Hinge

two bones joined so that they can move in one plane only

Example of hinge

elbow or knee

Ellipsoid

oval condyle that fits into an oval fossa allowing movement in two planes

Example of ellipsoid

between metatarsals and phalanges of the foot

Pivot

one bone that pivots on the axis of another, allowing rotation

Example of pivot

atlas and axis

Saddle

two saddle-shaped processes that fit together to allow movement in two planes

Example of saddle

between the thumb's metatarsal and the trapezium of the wrist.

Ball-and-Socket

a ball-shaped process that fits into a rounded fossa, allowing almost unrestricted movement

Example of ball-and-socket

between the head of the femur and the acetabulum

Getting Help Prepares Every Student Better

gliding, hinge, pivot, ellipsoid, saddle, ball-and-socket- synovial joints

Flexion

decreasing the angle of a joint

Extension

increasing the angle of a joint

Hyperextension

moving a joint beyond its normal range

Dorsiflexion

bending of the foot or the toes upward (superiorly)

Plantar flexion

bending of the sole of the foot by curling the toes toward the ground ( inferiorly)

Protraction

moving a part anteriorly (front) along a horizontal plane

Retraction

moving a part backward

Abduction

movement away from the midline

Adduction

moving an appendage's distal end toward the midsaggital plane

Inversion

turning inward

Eversion

turning outward

Circumduction

circular movement of a limb at the far end-cone shaped sweep

Rotation

moving a bone on its axis, as if on a pivot or axle

Pronation

turning the palm downward

Supination

palm facing up

Elevation

raising a body part

Depression

lowering a body part

Saggital plane movements

flexion, extension, hyperextension, dorsiflexion, plantar flexion, protraction, retraction

Frontal (corronal) plane movements

abduction, adduction, inversion, eversion

Circular movements

circumduction, rotation, pronation, supination

Special movements

elevation and depression