Ch. 2 Joints

Joints are formed

Where two or more bones meet

Abduction

Movement away from the median line of the body

Adduction

Movement towards or across the median line of the body

Flexion

Movement of bending/decreases angle between bones

Extension

Movement of straightening or stretching out/Increases angle between bones

Supination

Movement of turning the body or hand so that the front of the body faces upwards

Pronation

Movement of turning the body to face downwards, to lie face down

Gliding

Sliding of one bone upon another at a joint

Inversion

Movement of turning a part to face towards the median line

Forced Inversion

Forcibly inverting beyond normal

Eversion

Movement of turning a part away from the median line

Rotation

Movement of turning a part in one axis

Circumduction

Movement in a circular direction about a cone-shaped axis

Hyperextension

Extension beyond normal limit

Hyperflexion

Flexion beyond normal limit

Another name for Synovial Joints

Diarthroses

Another name for Cartilaginous Joints

Amphiarthroses

Another name for Fibrous Joints

Synarthroses

Most common type of joints found in the body

Synovial Joints

Synovial Joints

Freely Movable joints.
Consists of a fibrous capsule, synovial membrane, synovial fluid, and articular cartilage.

Fibrous Capsule

Outermost layer surrounding the joint cavity of a synovial joint

Synovial Membrane

Lines the inner surface of the fibrous capsule and bone surfaces, except where articular hyaline cartilage is found. Secretes the synovial fluid into the joint cavity

Synovial Fluid

Secreted into the joint cavity by the Synovial Membrane.
Acts as a lubricant and shock absorber.

Ligaments

Pass from one bone across the joint to the other bone - strengthen the joint.
Can be located inside, fused to, or completely outside the fibrous joint capsule

Synovial Hinge Joints

-The convex surface of one bone fits in a concave surface of the other to allow an angular motion similar to a hinge on a door.
-Allows for movement in a single plane, like a door hinge.
-Uniaxial joint (movement in one plane)

-Flexion, extension

-Ex. Elbow

Synovial Bicondylar Joints

-Biaxial joints (movements around two axes at 90 degrees to each other) but only minimal movement in one of the planes.
-Flexion, extension, rotation
-Ex. Knee

Synovial Ellipsoid (condyloid) Joints

-Biaxial Joint
-A type of synovial joint where an oval-shaped condyle of one bone fits into an elongated, elliptical cavity of another bone
-Flexion, extension, abduction, adduction
-Ex. Wrist

Synovial Saddle Joints

-Biaxial joints
-Flexion, extension, abduction, adduction, some of axial rotation

-Ex. Carpometacarpal joint

Synovial Pivot Joints

-Uniaxial Joint
-Projection sits in bony ring
-Rotation
-Ex. Radio-ulnar

Synovial Ball and Socket Joints

-Multiaxial joint (more than two planes)
-Ball shape in concave surface
-Flexion, extension, abduction, adduction, rotation, circumduction.
-Ex. Hip joint, shoulder joint.

Synovial Plane Joints

-Gliding only
-2 flat surfaces move over each other
-Ex. Sacroiliac joint

Cartilaginous Joints

-Slight minimal movement/May have no movement
-Ex. Pubic Symphysis

Fibrous Joints

-Also called immovable joints (may have minimal movement in the beginning)
-Later in life, the intervening fibrous tissue often disappears and the bone ends become united

-Ex. suture in the vault of the skull

Synovial Hinge Joint movement?

Uniaxial joints (movement in one plane). Flexion, extension.

Synovial Bicondylar Joint movement?

Biaxial joints (movement around two axes at 90 degrees to each other). Flexion, extension, rotation

Synovial Ellipsoid (condyloid) Joint movement?

Biaxial joint. Flexion, extension, abduction, adduction

Synovial Saddle Joints movement?

Biaxial joint. Flexion, extension, abduction, adduction, some of axial rotation

Synovial Pivot Joints movement?

Uniaxial joint. Rotation

Synovial Ball and Socket Joints movement?

Multiaxial joint (more than two planes). Flexion, extension, abduction, adduction, rotation, circumduction.

Synovial plane joint movement?

Gliding only