1. Joints

2. Joints (articulation)
Defined: A point of contact between bones, between cartilage and bones, or between teeth and bones.
When two bones articulate with one another we say that the 2 bones form a joint.
Arthrology = study of joints
Kinesiology = study of movement within the human body
Rheumatology = study of joint diseases and related conditions

3. Joint Strength, Flexibility, & Movement
Determined by:
Shape of the articulating bones
Flexibility of the ligaments that attach bone to bone
Tension of tendons and muscles of the articulating bones
Hormones
Dislocation: When articulating bones move from their normal positions.

4. Joint Structure Classification:
Type of connective tissue that holds the bones together.
The presence or absence of a synovial cavity (space between the articulating bones).

5. Joint Function Classification: Types:
Relates to the amount of movement allowed
Types:
Synarthrosis = Immoveable joint
Ex. pelvis , sutures, teeth
Amphiarthrosis = Slightly moveable joint
Ex. epiphysis, tibia-fibula, vertebrae and pelvic symphysis
Diarthrosis = A freely movable joint.
All synovial joints fall into this category
Come in many shapes
Allow for different types of movements

6. Types of Fibrous Joints
Fibrous joints are held together by fibrous connective tissue – bones lack a synovial cavity = little to no movement.
Suture
Unite the bones of the skull
The irregular interlocking edges decrease chances of fracturing
Functionally classified as Synarthrosis = Immovable

7. Types of Fibrous Joints
2. Syndesmosis
Contains dense fibrous connective tissue
Functionally classified as amphiarthrosis = Slight movement
Ex. The distal articulation between the tibia and the fibula.

8. Types of Fibrous Joints
3. Gomphosis
Cone shaped peg that fits into a socket
The only found in the articulations of the roots of the teeth with the sockets of the mandible & maxillae.
Functionally classified as synarthrosis = Immovable

9. Types of Cartilaginous Joints
Cartilagious joints are held together by fibrocartilage or hyaline cartilage
Bones lack a synovial cavity
Synchondrosis
A cartilage joint that connects with hyaline cartilage
Ex. Epiphyseal plate that connect the epiphysis and the diaphysis of a bone.
Functionally classified as synarthrosis = Immovable

10. Types of Cartilaginous Joints
Symphysis
A cartilage joint where ends of the articulating bones are covered with hyaline cartilage, but the bones themselves connect via fibrocartilage.
Ex. Pubic symphysis & between the bodies of vertebrae.
Functionally classified as amphiarthrosis = Slightly movable

11. Types of Synovial Joints
Presence of a synovial cavity
Functionally classified as diarthrosis = Freely movable
Epiphysis of bones are covered by articular (hyaline) cartilage
Reduces friction
Absorb shock
Contain ligaments: bundled fibers that connect bone to bone and give joints stability

12. Types of Synovial Joints
Planar AKA Plane or Gliding Joint
Flat or slightly curved bones
Allow for side to side & back and forth gliding motion
Hinge Joint
Concave surface meets the convex surface of another bone
Allow for opening & closing motion like the hinge of a door

13. Types of Synovial Joints
Pivot Joint
A rounded surface articulates with a ring formed by another bone or ligament.
Allows for rotation around its vertial axis.
Condyloid Joint
Convex-oval shape of one bone fits into the concave-oval shape of another.
Allows for up & down and side to side movement.

14. Types of Synovial Joints
Saddle Joint
Allows for side to side and back to forth movement.
Ball & Socket Joint
Ball like surface of one bone fits into the cup like depression of another.
Allows for free movement.

15. Joint Review Video (click picture)