Unit 3.3 - NURS Anatomy

Articulations

Joint

A point of articulation between two or more bones, especially such a connection that allows motion

Classifications of Joints

• Fibrous joints (synarthrosis)

• Cartilaginous joints (amphiarthrosis)

• Synovial joints (diarthrosis)

Fibrous joints

These joints are also called "fixed" or "immovable" joints, because they do not move. These joints have no joint cavity and are connected via fibrous connective tissue (eg. skull sutures)

Cartilaginous joints

These joints also have no joint cavity and the bones are connected tightly to each other with cartilage. These joints only allow a small amount of movement, so are also called "partly" or "slightly moveable" joints (eg. vertebral column)

Synovial joints

freely movable, and enclosed in a capsule with s…fluid that lubricates, nourishes cartilage, and removes debris. Found mainly in limbs, they allow wide movement but have a higher injury risk (e.g., dislocations).

Ligaments may reinforce the capsule. Movement range depends on bone fit, connective tissue flexibility, and ligament or muscle positioning (eg. knee joint)

6 kinds of synovial joints 

Gliding, hinged, pivot, condyloid, saddle, ball and socket

Gliding

Have the most simplistic range of motion of all synovial joints. They function to allow side-to-side and back-and-forth motions.

Hinged

Permit a back-and-forth motion, allowing parts of the body to extend and flex. With this particular joint, one bone must be concave and the other convex to allow the most extensive range of motion.

Pivot

Limited to circular motions; its joint is composed of a depressed bone and another cone-shaped bone that provide the ability to twist or rotate.

Condyloid

Allow side-to-side and up-down motion between an oval bone and a concave surface

Saddle

Have concave and convex surfaces fitting together, allowing greater motion than condyloid joints. Example: thumb’s carpometacarpal joint, enabling opposition

Ball and socket

Ball and socket joints provide the greatest range of motion for the body. They are composed of one rounded or convex bone that fits into a cupped depression or hole in another bone

Ligament

 Connect bone to bone - ligament - tough, regularly arranged connective tissue, slightly elastic

Tendon

Connect muscle to bone, enabling movement. The origin tendon attaches to the non-moving bone; the insertion tendon attaches to the moving bone