Joints

Fibrous joints

• Joints that are in close contact with one another.

• In the skull, these are called sutures.

http://www.geocities.com/akramjfr/sutural_parietal.jpg

Cartilaginous joints

• Joints that are connected by cartilage.

• This is seen in the vertebral column, though these joints are very limited in movement.

http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Motor%20Systems/cartilaginous%20joint.jpg

Synovial joints

• Exhibit most movement; secrete synovial fluid (lubricates the joints)

• Some have menisci, which are shock absorbers.

• These joints also have bursae that secretes the synovial fluid.

http://bioweb.wku.edu/courses/Biol131/images/joints.jpg

Types of synovial joints

• ABall-and-socket joints – has a ball of one bone that articulates with the socket of the next.

• The hip joint and the shoulder joint are ball-and-socket joints.

http://zimmer.com.au/web/enUS/images/products/surgery/shoulder_surgery1.jpg

• BCondyloid joint - oval-shaped condyle of one bone fits into an elliptical cavity of another bone.

• These are found in the metacarpals and phlanges.

• CGliding joints – These allow sliding and twisting movements.

• They are flat or slightly curved and are found in the ankle and wrist.

http://www.shockfamily.net/skeleton/GLIDING.JPG

• DHinge joint – This looks like a door hinge; one joint fits into another and allows for flexing.

• These are like the joints of the phlanges.

http://www.shockfamily.net/skeleton/HINGE.JPG

• EPivot joint – This allows for rotational movement around an axis.

• One bone forms a ring around another bone like the ulna and the radius, or the first two cervical vertebrae.

http://www.mc.edu/campus/users/cboothe/carastafford2_files/image019.jpg

• FSaddle joint – This joint is seen between one of the carpals and the metacarpal.

• The surface of one bone fits complementarily to another.

http://www.shockfamily.net/skeleton/SADDLE.JPG

Joint movements

• Occurs because a muscle is attached to a fixed part of the joint (origin) and to a movable part (insertion).

• 1Flexion – bending parts at a joint, like bending the knee.

• 2Extension – straightening parts at a joint, like straightening the knee.

http://www.gla.ac.uk/ibls/fab/images/anatomy/kneeflex.gif

• 3Dorsiflexion – flexing the foot at the ankle towards the shin.

• 4Plantar flexion – flexing the foot at the ankle towards the sole.

http://www.cannock.ac.uk/sports/images/muscle_actions/palantar_dorsi.gif

• 5Hyperextension – excessive extension of the parts of a joint.

• 6Abduction – moving a part away from midline.

• 7Adduction – moving a part toward midline.

http://www.whiplash101.com/EMG/RearendExplanation.jpg

HYPEREXTENSION

• 8Rotation – moving a part around an axis (shaking head)

• 9Circumduction – moving a part so that it follows a circular path.

• 10Pronation – turning the hand so that the palm is downward.

• 11Supination – turning the hand so that the palm is turned up.

http://arania.kamiki.net/Ambrose/Bernice%20Head%20Rotation.jpg

http://www.brianmac.demon.co.uk/mus24.gif

http://www.cannock.ac.uk/sports/images/muscle_actions/supination_pronation.gif

• 12Eversion – turning the foot so that the sole is outward.

• 13Inversion – turning the foot so that the sole is inward.

• 14Retraction – moving a part backward (like the chin)

• 15Protraction – moving a part forward.

http://www.octc.kctcs.edu/gcaplan/anat/Notes/Image577.gif

http://www.octc.kctcs.edu/gcaplan/anat/Notes/Image578.gif

• 16Elevation – raising a part.• 17Depression – lowering a part.

http://www.brianmac.demon.co.uk/mus8.gif