1. Notes: Joints

2. (1) How are bones hinged together?
Joints: Connection between two bones.
Filled with cartilage (padding)
Types of Joints:
Pivot
Condyloid
Plane
Hinge
Saddle
Ball-and-socket

3. (2) What is the purpose of Joints?
Allow for wider range of movement.
Circular
Angular
Reduce rigidity of bone structure.

4. (3) Pivot Joint
Rounded end of one bone, protrudes into a sleeve of another bone.
Movement = Uniaxial Rotation of one bone
Location = Vertebral Column (allowing head movement side to side “no”) and between the radius and ulna.

5. (4) Condyloid Joint Rotation along two axes (x and y)
Oval surface of one bone fits into the depression of another bone
Movement = Angular motion (flexion, extension, abduction, adduction, circumduction)
Location = Wrist and knuckles

6. (5) Plane Joint Straight gliding along 2 horizontal axes
Movement = short gliding
Location = Intercarpal and Intertarsal joints and vertebral

7. (6) Hinge Joint
One bone is cylindrical, and fits into the trough shape of the other bone
Movement = uniaxial hinge (flexion and extension)
Location = elbow and interphalangeal joints

8. (7) Saddle Joint
Similar to condyloid, but with greater freedom of movement.
Both bone surfaces are shaped like a saddle.
Movement = angular motions (flexion, extension, abduction, adduction, circumduction)
Location = thumbs and metacarpal joints

9. (8) Ball and Socket Joint
Rotation along 3 different axes.
One bone is spherical and fits into the cuplike socket of the other bone.
Movement = Universal (all types)
Location = shoulder and hips

10. (9) Injuring Joints Sprains: Dislocations:
Ligaments reinforcing a joint are stretched or torn
If torn badly, can be replaced with muscle
Usually result from inflexibility or irregular movement
Dislocations:
Bones are forced out of alignment
Usually result from serious falls and contact sports
Results in stretching of joint ligaments, leading to future dislocations