Anat 1Anat 1Chapter 8 : Chapter 8 :

ArticulationsArticulations

1. Synarthrosis (no movement)1. Bony Fusion (Synostosis)2. Fibrous (Suture and Gomphosis)3. Cartilaginous (Synchondrosis)

2. Amphiarthrosis (little movement)

1. Fibrous (Syndesmosis) 2. Cartilaginous (Symphysis)

FunctionalFunctional / / Structural Structural Classification of JointsClassification of Joints

Always synovial joints mono, di-, and triaxial Strength vs. motility The

greater the range of motion, the weaker the joint.

Dislocation = luxation

Partial dislocation = ?

“Double jointed”

3) Diarthrosis 3) Diarthrosis (free (free movement)movement)

Diarthroses = Synovial Diarthroses = Synovial JointsJoints

Have synovial cavity = space between two bones

Components that are always present (fig 8-1)

Components that are sometimes present

3 Types of Motion at 3 Types of Motion at Synovial JointsSynovial Joints

Linear motion = gliding

Angular motion : flexion, extension,

hyperextension ab-, adduction circumduction

Rotation left - right, internal or

medial, external or lateral supination, pronation

Special MovementsSpecial MovementsDorsiflexion, plantar flexion

Protraction, retraction

Elevation, depression

Eversion inversion

6 types of 6 types of DiarthrosesDiarthroses

1 Gliding Joint

2 Hinge Joint

3 Pivot Joint

4 Ellipsoidal joint

5 Saddle joint

6 Ball & Socket joint

Gliding JointGliding Joint

articulating surfaces flat.

• also found between carpals and tarsals

• only slight movement - rotation prevented by ?

Hinge JointHinge Joint

Convex surface of bone 1 fits into concave surface of bone 2

found in ?

monoaxial

Pivot JointPivot Joint

Projection of bone 1 articulates within ring of bone 2

Also found in proximal ends of ulna and radius pronation and supination

rotation

Ellipsoidal (Condyloid) Ellipsoidal (Condyloid) JointJoint

Oval shaped condyle of bone 1 fits into elliptical cavity of bone 2

Also found between phalanges & metacarpals/-tarsals

Angular motion in two planes (= )

Saddle JointSaddle JointArticular surfaces shaped like saddle and rider

Modified condyloid joint

Extensive angular motion without rotation

Also between malleus and incus

Ball and Socket JointBall and Socket Joint

Ball like surface of bone 1 fits into cuplike depression of bone 2

Found in ___________

Allows for flexion, ab- or adduction and rotation ( _____axial)

Representative Representative ArticulationsArticulations

Temporomandibular JointMostly hinge joint, some gliding and

rotationArticular disc

Intervertebral Intervertebral articulationsarticulations

Gliding joints between ____________________

Intervertebral discs: (Amphiarthroses)  annulus fibrosus: tough outer layer

(fibrocartilage) nucleus pulposus: soft, gelatinous core

Account for ~25% of vertebral column height – H2O loss during aging

Intervertebral ligaments

Fig 8-8

Disc ProblemsDisc Problems

Slipped disc vs. herniated disc

Most common sites for disc problems: C5 - C6 L4 - L5 L5 - S1

Lumbago

Laminectomy ( surgical removal vertebral arch by shaving laminae to access disc)

Fig 8-9

Glenohumeral Glenohumeral JointJoint

Type?

Greatest range of motion (due to loose and shallow)

Most frequently dislocated

Stability provided by?

Fig 8-15

Hip JointHip Joint

Deep well fitted _______ joint

Participants ?

Stabilization:

Extracapsular and intracapsular ligaments (ligamentum teres = ligamentum capitis femoris)

Surrounding muscles

Most important normal movement?

Knee JointKnee Joint

Much more complex than elbow

Much less stable than other ______

structurally 3 separate joints

Extra- and intracapsular ligaments

Locking of knee due to external rotation of tibia

Figs 8-16 & 17

The end