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Flashcards in Articulations Deck (21):

Definition of Articulation

-Place of contact between bones, bone & cartilage or bones & teeth


Classifications of Articulations

1. Structurally;
a) Fibrous: bones held together by dense regular CT
b) Cartilagenous: bones joint by cartilage
c) Synovial: fluid - filled cavity that separates cartilage-covered articulating surfaces of bones

2. Functionally;
a) Synarthrosis: immobile joint
b) Amphiarthrosis: Slightly mobile joint
c) Diarthrosis: freely mobile joint


Tradeoff between Mobility & Joint stability

-5 articulations from most mobile to lease mobile

*mobility and stability are inversely related

Glenohumeral joint -> Hip joint -> Elbow joint -> Intevertebral joints -> Suture (skull)


Name the 3 types of fibrous joints



Gomphoses, Sutures & syndesmoses

-General shape, where found and level of mobility

Gomphoses: resembles peg in socket
-only one= articulation of roots of teeth w/ mandible & maxillae (held in place by periodontal membrane)
Sutures: immobile fibrous joints (synarthrosis)
-only b/w certain bones of skull
-have distinct, interlocking usu. irregular edges that increase strength & decrease no. of fractures
Syndesmoses: Articulating bones joined by long strands of dense regular CT only
-amphiarthorsis (e.g. ulna & radius; tibia & fibia)


Name the 2 types of cartilaginous Joints

1. Synchondroses
2. Symphyses


Synchondroses & Symphyses;

-Mobility, function and examples

-Synchondroses: joined by hyaline cartilage
-all synarthroses
-e.g. attachment of first rib to sternum by coastal cartilage, constochondrial joints (boints b/w bony ribs and coastal cartilage), spheno - occipital synchondrosis found b/w body of sphenoid & basilar part of occipital bone
-Symphyses: pad of fibrocartilage b/w articulating bones
-resists compression & stresses
-acts as shock absorber
-e.g. pubic symphsis


Synovial Joints

-Are freely movable articulations that are separated by a space called the joint cavity (only type of articulation w/ it)
-Includes most commonly known joints (e.g. knee, elbow, glenohumeral)


Classification of Synovial joints (based on surfaces & types of movement they allow)

-Uniaxial: Bone moves in just one plane or axis
-Biaxial: Bone moves in 2 planes/axes
-Multiaxial: Bone moves in multiple planes/axes


Name the 6 types of Synovial joints (least to most mobile)

1. Plane joint
2. Hinge joint
3. Pivot joint
4. Condyle joint
5. Saddle joint
6. Ball & socket joint


Plane Joint

AKA planar or gliding joint
-simplest type
-only allows side to side movement
-articulates surfaces of bones that are flat or planar

e.g. Intercarpal and intertarsal joints


Hinge Joint

-convex surfaces of one bone fits into concave depression of other
-single axis

e.g. elbow joint (trochlea notch of ulna fits into troclea of humerous), knee & finger [interphalageal joint]


Pivot Joint

-1 articulating bone w/ rounded surface fits into ring formed by ligament and another bone

e.g. proximal radionuclear joint, atlantoaxial joint


Condyle Joint

AKA condyloid or ellipsoid
-biaxial w/ oval, convex surface on one bone concave on 2nd bone

e.g. metacarpphalngeal joints of fingers 2 to 5 (aka knucles


Saddle joint

-convex & concav regions on articulate surfaces of bones (e.g. carpometacarple joint of thumb)


Ball & socket Joint

-multiaxial joint
-spherical head of 1 fits into rounded, cuplike socket of other

e.g. hip joint and glenohumeral bone


Name the 4 types of movements at Synovial Joints

1. Gliding motion
2. Angular Motion
3. Rotational Motion
4. Special movements


Gliding motion

-2 opposing surfaces slide slightly back and forth or side-to-side
-angle between bones doesn't change
-typically occur along plane joints


Anglular Motion (7 associated terms)

-either increases or decreases angles between 2 joints
-flexion: decrease angle (anterior-posterior plane)
-extension: increase angle (AP plane)
-hyperextension: extension of joint >180 degrees
-lateral flexion: trunk of body moves in coronal plane laterally
-abduction: Move away - body part moves away from trunk of body
-adduction: move towards - body part moves toward body midline
-circumduction: proximal end remains stationary while distal end makes circular motion


Rotational motion

-pivoting motion in which bone turns on its own longitudinal axix

e.g. atlantoaxial joint

-pronation: medial rotation of forearm so palm of hand is directed posteriorly or inferiorly
-superination: forearm rotates laterally so palm faces anteriorly and radius parallel w/ ulna


Special movements

-Things that don't fit into other categories
-e.g. elevation/depression, dorsiflexion & planatar flexion, protraction & retraction & opposition