2. Articular Cartilage
Articular cartilage covers the articulating bones in synovial joints
and helps to transmit loads and reduce friction.
It is bonded tightly to the subchondral bone through the zone of
calcification, which is the end of bone visible on x-ray film.
The joint space visible on x-ray film is composed of the synovial
cavity and noncalcified articular cartilage.
3. Zone of the articular cartilage
• The outermost layer of cartilage is known
as the gliding zone, which itself contains a
superficial layer (outer) and a tangential
layer (inner).
• The outer segment is made up solely of
collagen randomly oriented into flat
bundles.
• The tangential layer consists of densely
packed layers of collagen, which are
oriented parallel to the surface of the joint.
4. Most articular surfaces of bone are covered by hyaline cartilage,
the most common type of cartilage.
A second type of cartilage is fibrocartilage and it is found where
more support is needed (meniscus of the knee joint, intervertebral
discs between the bodies of the vertebrae).
The third type of cartilage is elastic cartilage and it is found
where flexibility is needed (auricle of the ear, epiglottis).
5. Epiphysial plate: a cartilaginous
joint that is immovable
Intervertebral disc: a cartilaginous
joint that permits some movement
6. Joints are articulations between bones. Three types of joints are
identified in humans:
• Fibrous (synarthroses): bones joined by fibrous connective tissue
(examples include sutures of some skull bones, fibrous connections
between some long bones, and gomphoses [teeth in the jaw])
• Cartilaginous (amphiarthroses): bones joined by either cartilage or
cartilage and fibrous tissue; include primary (epiphyseal plates of growing
bones) and secondary types (intervertebral disc between adjacent vertebra
of the spine)
• Synovial (diarthroses): bones joined by a joint cavity filled with
synovial fluid, surrounded by a capsule, with articular cartilage covering
the opposed surfaces
7. Synarthrotic
Fibrous
Suture —nearly no movement Cranial sutures
Syndesmosis—some movement Distal tibia-fibula
Cartilaginous
Synchondrosis —temporary Epiphyseal plates
Symphysis —fibrocartilage Pubes Intervertebral discs
8. Suture: a type of fibrous joint that
allows little movement
Interosseous membrane: also a type of fibrous
joint that permits some movement
