SJSU SP24 BIOL-65 Chapter 9 - The Skeletal System IV: Joints

Joint (articulation)

point where two bones meet

Arthrology

study of joint structure, function, and dysfunction

Biomechanics

study of movements and mechanics in body

Kinesiology

study of musculoskeletal movement

Synostosis (bony) joints

immovable; two bones ossified together

Synarthrosis (fibrous) joints

collagen fibers bind adjacent bones; little to kno movement

Three types of Synarthrosis (fibrous) joints

Sutures, Gomphoses, Syndesmoses

Sutures

A line along which any two bones of the skull are immovably joined; Immobile or slightly movable.

Three Classifications of Sutures

Serrate, Lap (squamous), Plane (butt)

Serrate suture

interlocked

Lap (squamous) suture

overlapped

Plane (butt) suture

straight, nonoverlapped

Gomphoses

held in place by periodontal ligaments; slight movement under stress

Syndesmoses

Long collagen fibers

Amphiarthrosis (Cartilaginous) joints

Interlinked by cartilage

Two types of Amphiarthrosis (Cartilaginous) joints

Synchondroses, Symphyses

Synchondroses

bones bound by hyaline cartilage; i.e. epiphyseal plate, attachment of the first rib to the sternum

Symphyses

bones joined by fibrocartilage; i.e. pubic symphysis, intervertebral discs

Diarthrosis (Synovial) joints

points where two bones are separated by a narrow, encapsulated space filled with lubricating synovial fluid; varied mobility, freely movable to limited

General Anatomy of Synovial Joints

Articular cartilage; joint (articular) cavity, synovial fluid, joint (articular) capsule, outer fibrous capsule, inner synovial membrane

Accessory structures associated with synovial joints

tendons, ligaments, and bursae

Articular cartilage

a thin layer of hyaline cartilage covering the articular surface of a bone at a synovial joint, serving to reduce friction and ease joint movement

Joint capsule

Encloses joint cavity -- narrow fluid-filled space

Inner synovial membrane

Produces synovial fluid

Synovial fluid

lubricant consisting of fibroblast-like cells

Tendons

muscle to bone

Ligaments

bone to bone

Bursa

sac of synovial fluid

Tendon sheath

elongated bursa

Classes of Synovial Joints

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

Ball-and-socket joint

Multiaxial(>2)

Condylar (ellipsoid) joint

Biaxial(2)

Saddle joint

Biaxial(2)

Plane (gliding) joint

Biaxial(2)

Hinge joint

monoaxial

Pivot joint

Monoaxial(1)

Flexion

decreases angle joint

Extension

straightens joint angle

Abduction

moves away from midline

Adduction

moves toward midline

Elevation

raises body part

Depression

lowers body part

Protraction

anterior movement

Retraction

posterior movement

Circumduction

distal end of limb makes circle while proximal end is stationary

Rotation

bone spins on its long axis

Supination

moves palm to face anteriorly

Pronation

moves palm to face posteriorly

Special Movements of the Head and Trunk

Special Movements of the Mandible

Special Movements of the Hand and Fingers

Dorsiflexion

foot elevates at ankle

Plantar flexion

foot points down at ankle

Inversion

soles face medially

Eversion

soles face laterally

Temporomandibular joint (TMJ) -- jaw joint

the articulation of the condyle of the mandible with the mandibular fossa of the temporal bone.

Jaw joint classification

condylar, hinge, and plane

Jaw joint movements

elevation, depression, protraction, retraction, lateral and medial excursion

Jaw joint ligaments

lateral and sphenomandibular

Jaw joint bone articulation

condyle of mandible and mandibular fossa of temporal bone

Mandibular fossa of temporal bone

Mandibular condyle

Lateral ligament

Glenohumeral (humeroscapular) joint/shoulder joint

where the hemispherical head of the humerus articulates with the glenoid cavity of the scapula

Shoulder joint classification

ball-and-socket

Shoulder joint bone articulation

head of humerus and glenoid fossa of scapula

Shoulder joint movements

adduction, abduction, flexion, extension, circumduction, medial and lateral rotation

Shoulder joint ligaments

coracohumeral, transverse humeral, three glenohumerals

Glenoid labrum

ring of fibrocartilage that deepens socket

Acromioclavicular ligament

Coracoacromial ligament

Coracoclavicular ligament

Coracohumeral ligament

Elbow (humeroulnar and humeroradial) Joint

composed of two articulations--the humeroulnar joint and the humeroradial joint; stabilized by radial collateral and ulnar collateral ligaments

Elbow joint classification

hinge and pivot

Elbow joint movements

flexion, extension, pronation, supination, rotation

Elbow joint articulations

humeroulnar, trochlea of humerus, trochlear notch of ulna

Elbow joint ligaments

radial collateral, ulnar collateral, anular

humeroulnar joint

where the trochlea of the humerus joins the trochlear notch of the ulna

humeroradial joint

where the capitulum of the humerus meets the head of the radius

radial collateral ligament

ulnar collateral ligament

anular ligament

encircles the head of the radius and attaches at each end to the ulna

coxal (hip) joint

coxal joint; acetabular labrum; round ligament attaches to fovea capitis; iliofemoral, pubofemoral, and ischiofemoral ligaments

hip joint classification

ball-and-socket

hip joint movements

adduction, abduction, flexion, extension, circumduction, medial and lateral rotation

hip joint articulation

head of femur, acetabulum of hip bone

hip joint ligaments

iliofemoral, pubofemoral, ischiofemoral, ligamentum teres, transverse acetabular

iliofemoral ligament

pubofemoral ligament

ischiofemoral ligament

round ligament

transverse acetabular ligament

tibiofemoral (knee) joint

femorotibial joint, the largest and most complex diarthrosis of the body; functions as a hinge joint; has lateral and medial menisci; fibular collateral, tibial collateral, anterior cruciate, posterior cruciate ligaments

knee joint classification

primarily hinge

knee joint movements

flexion, extension, slight rotation

knee joint articulation

tibiofemoral, patellofemoral

fibular collateral ligament

tibial collateral ligament

anterior cruciate ligament