Chapter 8 : Articulations (pII)

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Anat 1
Chapter 8 :
Articulations
Functional / Structural
Classification of Joints
1.
Synarthrosis (no movement)
1.
2.
3.
2.
Bony Fusion (Synostosis)
Fibrous (Suture and Gomphosis)
Cartilaginous (Synchondrosis)
Amphiarthrosis (little movement)
1.
2.
Fibrous (Syndesmosis)
Cartilaginous (Symphysis)
3) Diarthrosis (free movement)

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”
Diarthroses = Synovial Joints
 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 Synovial
Joints
 Linear
motion = gliding
 Angular
motion :
 flexion,
extension,
hyperextension
 ab-, adduction
 circumduction
 Rotation
 left
- right, internal or medial,
external or lateral
 supination, pronation
Special Movements
Dorsiflexion, plantar flexion
Protraction, retraction
Elevation, depression
Eversion
inversion
6 types of Diarthroses
1
Gliding Joint
2
Hinge Joint
3
Pivot Joint
4
Ellipsoidal joint
5
Saddle joint
6
Ball & Socket joint
Gliding Joint
articulating
surfaces flat.
• also found between carpals and tarsals
• only slight movement - rotation prevented by ?
Hinge Joint
Convex surface of
bone 1 fits into
concave surface of
bone 2
 found
in ?
 monoaxial
Pivot Joint
rotation
Projection of bone 1 articulates within ring of
bone 2
Also found in proximal ends of ulna and
radius  pronation and supination
Ellipsoidal (Condyloid) Joint
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 Joint
Articular surfaces
shaped like saddle
and rider
Modified condyloid
joint

Extensive angular
motion without
rotation

Also between
malleus and incus
Ball 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 Articulations
Temporomandibular Joint
Mostly hinge joint, some gliding and rotation
Articular disc
Intervertebral articulations
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 Problems
 Slipped
 Most
 C5
disc vs. herniated disc
Fig 8-9
common sites for disc problems:
- C6
 L4 - L5
 L5 - S1
 Lumbago
 Laminectomy
( surgical removal vertebral
arch by shaving laminae to access disc)
Glenohumeral
Joint

Type?

Greatest range of
motion (due to
loose and
shallow)

Most frequently
dislocated

Stability
provided by?
Hip Joint
 Deep
well fitted _______ joint
 Participants
?
 Stabilization:
 Extracapsular
and intracapsular ligaments
(ligamentum teres = ligamentum capitis
femoris)
 Surrounding
 Most
muscles
important normal movement?
Fig 8-15
Knee Joint
 Much
more complex than elbow
 Much
less stable than other ______
 structurally
 Extra-
3 separate joints
and intracapsular ligaments
 Locking
of tibia
of knee due to external rotation
Figs 8-16 & 17
The end

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