Joints - A joint is the location at which two or more bones make
contact.Diagram of a typical Synovial Joint...
Structural Classifications of Joints
Fibrous joints connect bones without allowing any movement. The bones
of your skull and pelvis are held together by fibrous joints. The union
of the spinous processes and vertebrae are fibrous joints.
Cartilaginous joints are joints in which the bones are attached by
cartilage. These joints allow for only a little movement, such as in the
spine or ribs.
Synovial joints allow for much more movement than cartilaginous joints.
Cavities between bones in synovial joints are filled with synovial
fluid. This fluid helps lubricate and protect the bones. Bursa sacks
contain the synovial fluid.
Types of Joints (6)
A convex projection on one bone fits into a
concave depression in another permitting only flexion and extension as
This type of joint occurs when the touching
surfaces of two bones have both concave and convex regions with the
the two bones complementing one other and allowing a wide range of
The only saddle joint in the body is in the thumb.
The ball-shaped end of one bone fits
into a cup shaped socket on the other bone allowing the widest range of
including rotation. Examples include the shoulder and hip.
Oval shaped condyle fits into elliptical
cavity of another allowing angular motion but not rotation. This occurs
the metacarpals (bones in the palm of the hand) and phalanges (fingers)
between the metatarsals (foot bones excluding heel) and phalanges
Rounded or conical surfaces of one bone fit into
a ring of one or tendon allowing rotation. An example is the joint
axis and atlas in the neck.
Flat or slightly flat surfaces move against
each other allowing sliding or twisting without any circular movement.
happens in the carpals in the wrist and the tarsals in the ankle.