Chapter 9 ( technically not done)

Joints may allow

full movement, limited movement, or no movement

Joints provide ____ [e.g., bone alignment]Jointa

stability

joint components play a role in what ___ may occur

(e.g., ligaments, joint capsule, bone shape, bone articulation)

motion

Synarthrosis

no movement

Diarthrosis

freely moveable

wide variety of functions

Amphiarthrosis

small movement

connects bones

Hyaline cartilage

Fibrous Joints

Dense regular collagenous connective tissue connects bones

with no space between them

Stable (limited or no motion),

Gomphosis joint is formed by

periodontal ligament

connects tooth and bony socket in jaw (alveolus) [limited movement]

Gomphosis joint

Syndesmosis joint

formed by interosseous ligament

between tibia and fibula, ulna and radius

more movement, but limited

Syndesmosis joint

Stabilize rib cage

Rib connection to manubrium and sternum

Ligament

connects one bone to another

additional strength and reinforcement to joint

Tendon

connects muscle to bone

cross over associated joints provides stabilization when muscles contract

Muscle tone

continuous level of muscle contraction

provides continual stabilizing force

long bursa

surrounds tendons

protects tendons as they slide across joint

Tendon sheath

Least to Most mobile

Plane joints, Hinge joints, Pivot joints, Condylar joints, Saddle joints, Ball-and-socket joints

Nonaxial

Bones slide past one another

Uniaxial joint

Bone moves in just one plane or axis

Biaxial joint

Bone moves in two planes or axes

Multiaxial joint

Bone moves in multiple planes or axes

Types of Motion at Synovial Joints

Gliding, Angular, Rotational, Special movements

Motions that occur only at specific joints

Flexion

decreases angle between bones (move closer together)

Extension

increases angle between bones (move further apart)

Hyperextension

extension beyond anatomical position of joint

body part moves away from midline of body

Abduction

Adduction

body part moves toward midline of body

only unpaired angular movement

cone-shaped motion

combination of flexion-extension and abduction-adduction

Circumduction

Opposition

allows thumb to move across palmar surface of hand

Reposition

opposite movement returns thumb to anatomical position

Depression

body part moves in inferior direction

Elevation

body part moves in superior direction

Protraction

body part moves in anterior direction

Retraction

body part moves in posterior direction

Inversion

rotational motion

plantar surface of foot rotates medially

toward midline of body (little toe touching floor)

Eversion

rotates foot laterally away from midline

(big toe touching floor)

Dorsiflexion

angle between foot and leg decreases

(heel on floor)

Plantarflexion

angle between foot and leg increases

(toes on floor)