Synovial Joints
DIARTHROTIC ARTICULATIONS
What are synovial joints?
 Freely movable joints
 Contain a cavity filled with thick, slippery fluid
(Synovial fluid)
 Found mostly in articulations of the appendicular
skeleton
Articular Cartilage
 Covers the ends of bones
 Made of hyaline cartilage
 Reduces friction between bones
Cartilage wearing
away causes pain and
restricted motion
Types of synovial joints:
 Gliding (plane)
 Pivot
 Hinge
 Ball and socket
 Elipsoid
(Condyloid)
 Saddle
Gliding or Plane joints:
 Formed between 2 opposing flat surfaces
 Bones slide over each other
Pivot Joints:
 Rotation around an axis
Hinge Joints:
 Part of one bone fits into a convex cavity in another
bone.
 Motion is in one plane, back and forth
Ball-and-Socket Joint
 A round projection on one bone (head) fits into a
depression (socket) on another bone.
 Allows a wide range of motion
 Easy to dislocate
Ellipsoid (Condyloid) Joints:
 Modified ball and socket joints in which the head of a
bone is similar in shape to a football
 Moves in two axes, but restricts rotational motion
Saddle Joints
 Made by 2 saddle-shaped surfaces at right angles to
each other
The Knee Joint
THE ARTICULATION OF 3
BONES
Bursa/e – Sacs filled
with synovial fluid for
cushioning
ACL and PCL –
Ligaments that
connects the tibia to
the femur
Meniscus – crescentshaped fibrocartilage
pads that help
cushion joints
The Knee
 A modified hinge joint
 Allows flexion, extension, and limited rotation
Knee
dislocation –
owww!
Chicken Leg Dissection
EXAMINATION OF THE KNEE
JOINT