DIARTHROTIC ARTICULATIONS

Synovial Joints

What are synovial joints?

Freely movable jointsContain a cavity filled with thick, slippery fluid

(Synovial fluid)Found mostly in articulations of the appendicular

skeleton

Articular Cartilage

Covers the ends of bonesMade of hyaline cartilageReduces friction between bones

Cartilage wearing away causes pain and restricted motion

Types of synovial joints:

Gliding (plane)

PivotHingeBall and

socketElipsoid

(Condyloid)Saddle

Gliding or Plane joints:

Formed between 2 opposing flat surfacesBones 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 motionEasy 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 ARTICULATION OF 3 BONES

The Knee Joint

Bursa/e – Sacs filled with synovial fluid for cushioning

ACL and PCL – Ligaments that connects the tibia to the femur

Meniscus – crescent-shaped fibrocartilage pads that help cushion joints

The Knee

A modified hinge jointAllows flexion, extension, and limited rotation

Knee dislocation – owww!

EXAMINATION OF THE KNEE JOINT

Chicken Leg Dissection

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