Synovial Joints

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