Make your own free website on Tripod.com
Skeletal System
Joints

HOME

Pre-Quiz
Types of Skeletons
Joints
Skeletal Functions
Types of Bones
Structure of Long Bones
Microscopic Structure
Skeletal Development
Axial Skeleton
Appendicular Skeleton
Interactive Skeleton
Diseases, Disorders and Fractures
Links
Post-Quiz

Joints, or articulations, are places where two or more bones attach. 
 
There are three basic types of joints classified by the level of allowed movement:
 
Synarthrotic - are immovable articulations, such as the sutures in the skull, formed by the fusion of two bones
 
Amphiarthrotic - slightly movable articulations, joined with cartilage between them
      ex: Symphysis Pubis between the two Pubis bones of the Pelvis
 
Diarthrotic - freely movable articulations, contain joint capsule and layers of cartilage over the ends of the two joining bones
      ex: shoulder, elbow, wrists...
  
The basic structure of all diarthrotic joints are the same:
      - cartilage lines the ends of the bones meeting at the joint to prevent friction
      - synovial membranes line the joint and secretes synovial fluid for lubrication to aid in smooth movement
      - the individual bones are connected together via ligaments, and attach to the muscles which move them via tendons

Basic Structure of a Joint (Knee)
kneejoint.jpg

No-So-Basic Structure of a Diarthrotic Joint
joint02.gif

The majority of joints in the human body are diarthrotic.  Each joint is classified by the type of movement it creates:

joints.gif