Review 2A - Joints & Articulations

synarthrosis

• immovable

• ex: between skull bones

amphiarthroses

• slightly movable

• ex: between pubic bones

diarthroses

• freely movable

• ex: knee, shoulder, hip

fibrous joints

skeletal elements held together by fibrous connective tissue

fibrous joint types - suture

• connections by short fibers

• interlocking to hold elements together and allow for growth

• synarthroses (immovable)

• ex: between cranial bones

fibrous joint types - syndesmosis

• connection by short ligament

• synarthrotic

fibrous joint types - gomphosis

• connection by short fibers — periodontal ligament

• synarthrotic

• tooth in socket

fibrous joint types - interosseous membrane

• fibrous membrane

• between radius and ulna

• between tibia and fibula

cartilaginous joints

skeletal elements held together by cartilage

cartilaginous joints types - synchondrosis

• bones held together by hyaline cartilage

• synarthroses (immovable)

• ex: epiphyseal plate, manubrium—rib 1

cartilaginous joints types - symphysis

• hyaline cartilage on surface of bones

• fibrocartilage pad between bones

• amphiarthroses (slightly movable)

• ex: between bodies of vertebrae, between pubic bones

synovial joints

• complex joint structure

• diarthrotic (feely movable)

• most limb joints

synovial joint types

• pivot (rotation)

• plane (gliding)

• ball and socket (multiaxial)

• condyloid (biaxial)

• hinge (monaxial)

• saddle (multiaxial)

synovial joint - articular capsule

• holds bones together

• creates enclosed synovial cavity filled with synovial fluid

• outer fibrous layer

• inner synovial membrane > produces synovial fluid

synovial joint - articular cartilage

• hyaline cartilage; covers ends of opposing bones

• absorbs compression

• slick, reduces friction and wear on bones

• usually lacks perichondrium

synovial joint - synovial fluid

• viscous fluid in synovial cavity produced by synovial membrane

• lubricates, reduces friction

• absorbs compression

• delivers oxygen and nutrients to articular cartilage

synovial joint - reinforcing ligaments

• strengthen joint

• may be extracapsular (outside of articular capsule)

• may be intracapuslar (within articular capsule)

synovial joint - articular disk

• fibrocartilage

• improves fit between bones

• reduces wear, absorbs shock

• ex: jaw, knee

synovial joint - bursae and tendon sheaths

• fluid-filled sac

• reduce friction

synovial joint - blood vessels

contribute to synovial fluid

synovial joint - nerves

• receptors for pain

• stretch (position, posture)

hinge joint

forward and backward movement

condyloid joint

• forward and backward movement

• spreading movement

• side to side movement

saddle joint

oppositional movement

plane joint

gliding/sliding movement

ball and socket joint

• forward and backward movement

• in and out movement

• side to side movement

• rotation movement

pivot joint

rotating movement

flexion

• decreases angle

• forward

• (expect knee > backward)

extension

• increases angle

• backward

• (expect knee > forward)

hyperextension

increases angle beyond 180 degrees/anatomical position

lateral flexion

sideways movement of head or trunk

abduction

• away from midline of body

• spreading

adduction

• toward midline of frontal plane

• together

lateral rotation

spinning outward

medial rotation

spinning inward

supination

palm upward

pronation

palm downward

opposition

thumb across hand

protraction

moving body part anteriorly

retraction

moving body part posteriorly

elevation

moving body part superiorly

depression

moving body part inferiorly

plantar flexion

straitens out ankle

dorsiflexion

bends ankle

inversion

soles of feet inward/medially

eversion

soles of feet outward/laterally