Chapter 8: Articulation System 1

articulation

site where 2 or more bones meet

function of joints

give skeleton mobility

hold skeleton together

functional classification of joints

based on amount of movement allowed by the joint

3 functional classifications are

synarthroses - immovable

amphiarthroses - slightly movable

diarthroses - freely movable

structural classification focuses on…

material binding bones together

whether or not a joint cavity is present

3 structural classifications are…

fibrous

cartilaginous

synovial

fibrous joints - general info

the bones are joined by fibrous tissue

mostly synarthroses

fibrous joints - sutures

rigid, interlocking joints

synarthroses

structure of the skull

fibrous joints - syndesmoses

bones connected by ligaments

synarthroses, some amphiarthroses

distal tibiofibular joint, interosseous membrane between radius and ulna

fibrous joints - gomphoses

peg-IN joints

• peg & socket joint - immovable/fixed joint where a cone-shaped, peg-like process fits tightly into a hollow socket

synarthroses

between tooth and toot socket

cartilaginous joints - general info

bones are joined by cartilage

synarthroses/amphiarthroses

cartilaginous joints - synchondroses

hyaline cartilage unites the bones

synarthroses

epiphyseal plates of children, joint between the costal cartilage of the first rib and the sternum

cartilaginous joints - symphisis

fibrocartilage unites the bones

amphiarthroses

intervertebral joints and the pubic symphysis of the pelvis

synovial joints

joints in which the articulating bones are separated by a fluid-containing joint cavity

all are diarthroses (freely movable)

include all limb joints, most joints of the body

synovial joints - distinguishing features

articular cartilage - hyaline cartilage

joint (synovial) cavity - small potential space

articular (joint) capsule

• outer fibrous capsule - dense irregular connective tissue

• inner synovial membrane - loose connective tissue

synovial fluid

• viscous slippery filtrate of plasma & hyaluronic acid

• lubricates and nourishes articular cartilage

3 possible types of reinforcing ligaments

• capsular (intrinsic) - part of fibrous capsule

• extracapsular - outside capsule

• intracapsular - deep to capsule; covered by synovial membrane

rich nerve and blood vessel supply

synovial joints - friction reducing structures

bursae

• flattened, fibrous sacs lined w/ synovial membranes, contain synovial fluid

• commonly act as “ball bearings” where ligaments, muscles, skin, tendons, or bones rub together

tendon sheath

• elongated bursa that wraps completely around a tendon

synovial joints - movement

muscle attachments across a joint

• origin - attachment to immoveable bone

• insertion - attachment to movable bone

muscle contraction causes insertion to move toward origin

movements occur along transverse, frontal, or sagittal planes

synovial joints - range of motion

nonaxial - slipping movements only

• type of joint motion where flat/slightly curved bone surfaces slide or glide past each other without rotating around a specific axis

uniaxial - movement in one plane

biaxial - movement in two planes

multiaxial - movement in or around all 3 planes

movements at synovial joints

gliding

angular movements

• flexion, extension, hyperextension

• abduction, adduction

• circumduction

rotation movements

• medial and lateral rotation

special movements

• supination, pronation

• dorsiflexion, plantar flexion of the foot

• inversion, eversion

• protraction, retraction

• elevation, depression

• opposition

movements at synovial joints - gliding movements

one flat bone surface glides or slips over another similar surface

examples:

• intercarpal joints

• intertarsal joints

• between articular processes of vertebrae

movement at synovial joints - angular movements pt. 1

movements that occur along the sagittal plane

flexion - bending movement that decreases the angle of the joint

extension - reverse of flexion, joint angle is increased

hyperextension - excessive extension beyond normal range of motion

movement at synovial joints - angular movements pt. 2

dorsiflexion & plantar flexion - up and down movement of the foot

abduction - movement away from midline

adduction - movement toward the midline

circumduction - movement describes circular motion in space

movements at synovial joints - rotation

turning of a bone around its own long axis

examples:

• between C1 and C2 vertebrae

• rotation of humerus and femur

movements at synovial joints - special movements (foot up/down)

movements of the foot

• dorsiflexion - upward movement

• plantar flexion - downward movement

movements at synovial joints - special movements (forearm)

movements of the forearm

• supination - palms facing forward

• pronation - palms facing backward

movements at synovial joints - special movement (foot side to side)

movements of the foot

• inversion - turn sole medially

• eversion - turn sole laterally

movements at synovial joints - special movements (transverse plane)

movements in a transverse plane

• protraction - anterior movement

• retraction - posterior movement

movement at synovial joints - special movements (body parts)

elevation - lifting a body part superiorly

depression - lifting a body part inferiorly

movements at synovial joints - special movement (thumb)

opposition of the thumb

• movement in the saddle joint so that the thumb touches the tips of the other fingers

classification of synovial joints

based on shape of articular surface

• plane

• hinge

• pivot

• condyloid

• saddle

• ball and socket

classification of synovial joints - plane

nonaxial

intercarpal and intertarsal joints

gliding

classification of synovial joints - hinge

uniaxial

elbow joint & knee

flexion & extension

classification of synovial joints - pivot

uniaxial

proximal radioulnar joint

pronation and supination

classification of synovial joints - condyloid

biaxial

metacarpopharyngeal joint

flexion, extension, abduction, adduction

classification of synovial joints - saddle

biaxial

carpometacarpal joint of thumb

flexion, extension, adduction, abduction

classification of synovial joints - ball and socket

multiaxial

hip and shoulder joint

all movements

comparison of hip & shoulder - bones in the joint

shoulder -

• head of humerus & glenoid fossa of scapula

• glenoid labrum

hip -

• head of femur and acetabulum

• acetabular labrum

comparison of hip & shoulder - type of synovial joint

shoulder - ball and socket

hip - ball and socket

comparison of hip & shoulder - joint capsule

present in hip and shoulder

comparison of hip & shoulder - reinforcing ligaments

shoulder

• coracohumeral ligament

• three glenohumeral ligaments

hip

• iliofemoral

• ischofemoral

• pubofemoral

comparison of hip & shoulder - other ligaments

shoulder

• transverse humeral ligament

hip

• ligamentum teres

comparison of hip & shoulder - reinforcing muscle tendons

shoulder -

• tendon of the longhead of biceps, rotator

• cuff tendons -

  • subscapularis, supraspinatus, infraspinatus, teres minor

hip -

• all the muscles that surround the hip joint

comparison of hip & shoulder - movement at the joint

shoulder -

• all movements (multiaxial)

hip -

• all movements (multiaxial)

comparison of elbow & knee joint - bones in the joint

elbow -

• trochlear of ulna and trochlea of humerus

• head of radius and radial notch of ulna

knee -

• femoropatella joint - between femur and patella

• lateral and medial tibiofemoral joints - between the condyles of femur and medial & lateral menisci of tibial condyles

comparison of elbow & knee joint - type of synovial joint

elbow -

• hinge joint

• pivot joint

knee -

• hinge joint - modified

• plane (gliding)

comparison of elbow & knee joint - joint capsule

elbow -

• present

knee -

• anterior part of the capsule is

  • lateral and medial patellar retinacula

  • patellar ligament

• medial and lateral menisci - semicircular fibrocartilage that functions as a wedge between the bones

comparison of elbow & knee joint - reinforcing ligaments

elbow-

• ulnar ligament

• radial ligament

• prevent side to side movement

knee -

• tibial collateral ligament

• fibular collateral ligament

• prevent side to side movement

comparison of elbow & knee joint - other ligaments

elbow -

• annular ligament

knee -

• anterior cruciate ligament - prevents posterior displacement of femur

• posterior cruciate ligament - prevents anterior displacement of femur

• anterior/posterior naming is referring to direction of tibial movement being prevented

comparison of elbow & knee joint - reinforcing muscle tendons

elbow -

• muscles that surrounds it

knee -

• muscles that surrounds it

comparison of elbow & knee joint - movement at the joint

elbow -

• flexion and extension

• pronation and supination

knee -

• gliding

• flexion and extension