Download 03 - joints

JOINT
It is the site where
two or more bones
come together,
where there is
movement or not.

FIBROUS JOINTS
The articulating 
surfaces are joined by
fibrous tissue.
Very little movement 
is possible.
E.G : 
(1) Sutures of the 
vault of the skull.
(2) Inferior tibiofibular 
joints.
CARTILAGENOUS JOINTS
A. Primary 
Cartilagenous
The bones are united 
by a plate of hyaline
cartilage.
E.G : 
1. Between the 
Epiphysis and
Diaphysis of a growing
bone.
2. Between the first rib
and the sternum.

CARTILAGENOUS JOINTS
B. Secondary 
Cartilagenous
The bones are united by a 
plate of fibrocartilage.
Their articulating surfaces 
are covered by a thin plate
of hyaline cartilage.
E.G : (1) joints between 
the vertebral bodies.
(2) Symphysis pubis. 
SYNOVIAL JOINT
It has a great 
degree of freedom
of movement.
The articulating 
bones are covered
by hyaline cartilage
and separated by a
joint cavity.
SYNOVIAL JOINT
The cavity is lined by
synovial
membrane.
It is protected on the
outside by a tough
fibrous capsule.
The synovial 
membrane
produces a
lubricating fluid
(synovial fluid)

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CLASSIFICATION OF SYNOVIAL
JOINTS
1. Plane: 
The articulating 
surfaces are flat
and the bones slide
on one another.
E.G : 
Sternoclavicular 
and
Acromioclavicular
joints.
CLASSIFICATION OF SYNOVIAL
JOINTS
2. Hinge : 
It is a uni axial joint 
(E.G. Elbow, Knee and
Ankle joints.
3. Pivot : 
A central bony pivot is
surrounded by a bony
ligamentous ring.
E.G. (Atlanto-axial, 
superior radioulnar ).

CLASSIFICATION OF SYNOVIAL
JOINTS
4. Condyloid : 
Two convex articular 
surfaces articulate with
two concave. (E.G.)
Metacarpophalangeal
(kunckle joints).
5. Saddle : 
The articulating surfaces
are reciprocally
concavoconvex. (E.G.)
Carpometacarpal joint
of the thumb.

CLASSIFICATION OF SYNOVIAL
JOINTS
6. Ellipsoid : 
An elliptical convex
articular surface
fits into an elliptical
concave one.
(E.G.) Wrist 
joint.

CLASSIFICATION OF SYNOVIAL
JOINTS
7. Ball and 
Socket
A ball –shaped 
head of one bone
fits into a socket
like concavity of
another.
E.G. (Shoulder 
and Hip).
STABILITY OF THE JOINTS
1. The Articular 
surfaces: shape, size and
arrangement (E.G.) ball
and socket of hip joint.
2. Ligaments : 
A. Fibrous : they prevent
excessive movement in a
joint.
If the stress is continuous
for long, they become
stretched.
(E.G.) ligaments between
the bones forming the
arches of the foot.


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STABILITY OF THE JOINTS
B. Elastic : 
The ligaments 
between ear ossicles
have an important
role in supporting
the joints and return
the bones to their
original position.
STABILITY OF THE JOINTS
3. Muscle tone : 
In most joints it is 
the major factor
controlling stability.
(E.G.) the muscles 
around the
shoulder joint.
TERMS OF MOVEMENT
1. Flexion : 
It takes place in the 
sagittal plane.
It is usually an anterior
movement.
2. Extension : 
It is straightening of 
the joint.
It takes place in a 
posterior direction.

TERMS OF MOVEMENT
Lateral flexion :
It is movement in
the coronal plane.


TERMS OF MOVEMENT
3. Abduction : 
It is movement of a limb 
away from the midline of the
body in the coronal plane.
4. Adduction : 
It is movement of a limb 
toward the body in the
coronal plane.
5. Circumduction : 
It is the combination of 
flexion, extension,abduction
and adduction.
TERMS OF MOVEMENT
6. Medial rotation : 
The anterior surface of
the part faces medially.
7. Lateral rotation: 
The anterior surface of
the part faces laterally.

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TERMS OF MOVEMENT
8. Pronation of the 
forearm:
It is medial rotation of 
the forearm so that the
palm faces posteriorly.
9. Supination of the 
forearm:
It is lateral rotation of 
the forearm so that the
palm faces anteriorly.
TERMS OF MOVEMENT
10. Planter 
flexion and
Dorsiflexion of
the foot.
11. Inversion : 
The sole faces in a
medial direction.
12. Eversion : 
The sole faces in a
lateral direction.
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