2. Joints, also called articulations, are functional junctions
between two bones
The science of joints is called arthrology.
Functions of joints
1. Bind skeleton together
2. Enable body movements
3. Makes growth possible
4. Permit changes in skeleton for childbirth
3. Classification of Joints
Classifications based on amount of movement
1. Synarthrotic = immovable
2. Amphiarthrotic = slightly moveable
3. Diarthrotic = fully movable
Classifications by types of tissue:
1. Fibrous joint = dense connective tissue
2. Cartilaginous joint = bones connected by cartilage
3. Synovial joint = contains a synovial membrane
4. Fibrous Joints
There are three (3) types of fibrous joints:
• Syndesmosis
• Suture
• Gomphosis
1. Syndesmosis:
Bones are connected by a sheet
or bundle of fibrous tissue.
Examples include the
interosseous membrane and
interosseous ligaments
between the tibia and fibula.
Interosseous membrane between tibia
and fibula is a syndesmosis joint.
5. Fibrous Joints
2. Suture:
• Thin layer of dense
connective tissue
• Connects flat bones of the
skull (sutural ligaments)
•Synarthrotic
3. Gomphosis:
• Cone-shaped bony process
in a bony socket
• Example includes a tooth
anchored into a bony socket
6. Cartilaginous Joints
• There are two (2) types of cartilaginous joints:
• Synchondrosis
• Symphysis
1. Synchondrosis
• Bones are united by a band of
hyaline cartilage.
•
Located between manubrium
of sternum & 1st rib
•
Also located at epiphyseal
plates of developing bone
•
Movement is synarthrotic
7. Cartilaginous Joints
2. Symphysis
• A pad of fibrocartilage
between two bones
•
Examples include the pubic
symphysis and intervertebral
discs
•
Movement is amphiarthrotic.
8. General Structure of Synovial Joints
Synovial Joints are Freely movable (Diarthrotic)
Structures include:
• Articular cartilage
•
Synovial membrane –
secretes synovial fluid
•
Joint cavity – filled with
synovial fluid
•
Joint capsule – dense
connective tissue that
stabilizes and protects joint
Figure 8.7 The generalized
structure of a synovial joint.
9. General Structure of Synovial Joints
Structures include:
• Ligaments – bundles of
collagenous fibers that
reinforce the joint capsule
•
Menisci (sing. Meniscus) –
pad of fibrocartilage that
separates some joints.
•
Bursa – sac filled with
synovial fluid.
• Bursitis = inflammation
of bursa
Figure 8.8 Menisci separate the articulating surfaces
of the femur and tibia. Several bursae are
associated with the knee joint.
10. Types of Synovial Joints
1. Ball-and-socket
•
•
•
•
rounded head + cup-shaped socket.
Movement in all planes (multi-axial).
Allows for rotation
Includes hip joint and shoulder joint.
2. Condylar joint
•
•
•
•
Oval condyle + elliptical socket
Movements in most planes (bi-axial)
No rotational movement
Joints between metacarpals and
phalanges/
11. Types of Synovial Joints
3. Plane (Gliding) Joint
• Flattened bones slide across each
other
• Includes carpals and tarsals
• ribs 2-7 articulate with sternum
4. Hinge joint
• Increases or decreases angel
between bones
• Includes elbow joint
• Joints between phalanges
12. Types of Synovial Joints
5. Pivot Joint
• Rotation around a central axis
(uni-axial)
• Joint between radius and ulna
• Joint between atlas (C1) and
axis (C2).
6. Saddle Joint
• 2 concave bones positioned at
right angles
• Includes metacarpal and carpal
of thumb
End of Chapter 8, Section 1
