1. THE SKELETAL JOINTS

2. JOINTS Joints are where two or more bones articulate (move).
Joints are classified according to how much movement they allow.
1. Suture – these are fixed or immovable joints such as the cranium, sacrum and the coccyx.
2. Cartilaginous – these are slightly movable joints such as the vertebrae.
3. Synovial – these are freely movable joints such as the shoulder and hip.

3. Fibrous Joints
Bones are united by dense connective tissue consisting of collagen fibers which run between bones.
There is no joint cavity.
ONLY found in the skull.

4. Cartilaginous Joints
Joints where the articular surfaces of the bones forming the joints are attached to each other by cartilage and ligaments.
Allows only a limited degree of movement.
Examples:
cartilage between vertebrae,
between the pubic bones

6. Synovial joints There are 6 types of synovial joint.
1. Ball & socket – hip and shoulder.
2. Hinge – knee, elbow and ankle.
3. Pivot – radius/ulna, atlas/axis (neck).
4. Saddle – thumb.
5. Condyloid – wrist.
6. Gliding – between vertebrae in spine.

7. Ball & Socket joints The hip joint
The head of the femur fits into a deep fossa called the acetabulum on the pelvic bone.
This deep cavity gives the hip joint stability.
The presence of strong ligaments add to the stability making it difficult to dislocate the hip.

8. Stability is improved by ligaments and muscles.
Ball & Socket joints continued…
The shoulder joint
The head of the humerus fits into a shallow cavity on the scapula called the glenoid fossa.
The shoulder is the most mobile joint in the body but is also fairly unstable because of the shallow cavity.
Stability is improved by ligaments and muscles.

9. Hinge Joints The knee joint
In the knee joint the femur articulates with the tibia.
The patella (knee cap) helps to give a better angle of pull.
The fibula is not part of the knee joint and so the tibia is the weight bearing bone.

10. In the ankle, the talus articulates with the tibia and fibula.
Hinge Joints Continued…
The ankle joint
In the ankle, the talus articulates with the tibia and fibula.
Ligaments provide stability to the joint.
The elbow joint
In the elbow the humerus articulates with the radius and the ulna.
Movement can only occur in one plane.

11. The Pivot Joint The radius/ulna
In this joint the radius and ulna articulate within the elbow joint.
This joint allows the elbow some twisting movement.
Atlas/axis
In this joint the atlas and axis bones articulate to allow a rotation movement as in shaking your head.

12. Condyloid
The wrist
Bones are oval in shape with one concave and the other convex.
Move from side to side and back and forth, but NO rotation.
In this joint the radius and ulna bones articulate with 3 of the carpal bones.

13. Plane Joint (Gliding joint)
Spine, carpals and tarsals
Bone surfaces are flat and only short, gliding movements are allowed.

14. Saddle Joint
This type of joint occurs when the touching surfaces of two bones have both concave and convex regions with the shapes of the two bones complementing one other and allowing a wide range of movement.
The only saddle joint in the body is the thumb.

15. Synovial Joint Anatomy
Ligaments – connect bone to bone
Tendons – connect muscle to bone
Cartilage – cushion between bones
Synovial Fluid – lubrication/oil to reduce friction between bones
Joint Cavity – space full of synovial fluid

16. Articular/HyalineCartilage
Knee Joint
Articular/HyalineCartilage
Tendon