Nicholas Lai
10TJ
Ms. Bolton
Joints
A joint in your body is the site where bone meets another bone in your body. There are
many joints in your body as an adult body possesses of 206 bones! These joints are
classified into 3 groups by the amount of movement they allow. The 3 groups are
immovable (fibrous), slightly movable (cartilaginous) and freely movable (synovial)
joints. I am going to talk about some of the synovial joints. Synovial joints designs to
permit maximum movement in at least 1 direction. The ends of the bones are covered
with cartilage and they hold bones together. There are 6 main types of synovial joints:
Ball and socket, Hinge, Gliding, Saddle, Pivot and Condyloid.
Ball and socket joint:
The ball and socket joint is where a bone which has an end shaped like a ball fits into a
cup shaped socket in another bone allowing the widest range of motion like a 360 degree
rotation. Examples of ball and socket joints in your body are the shoulder and hip joint
where the ball shaped end of the humerus bone of your arm fits into the socket of your
scapula bone. Same as the hip bone, the ball shaped end of the femur fits into the socket
of the pelvis. Here are two pictures:
Hip joint
http://www.kettering.edu/visitors/
storypics/shoulder-joint.jpg
http://www.eorthopod.com/ima
ges/ContentImages/hip/hip_art
hroplasty/hip_arthroplasty_anat
01.jpg
Nicholas Lai
10TJ
Ms. Bolton
Hinge joint:
Like your elbow, a hinge joint is where convex projection on one bone fits into a concave
depression. Your elbow hinge bone consists of three bones. The upper portion of the
hinge, the convex projection, is at the end of the upper arm bone (humerus), and the
concave depression is the top of the two forearm bones (radius and ulna) which are side
by side and are joined to each other on one end. All three of these bones are in contact
with each other which makes up the hinge joint.
Elbow
hinge joint
http://www.m
yelbow.com/i
mages/homee
lbow.jpg
Hinge joint
http://upload.wikime
dia.org/wikipedia/co
mmons/thumb/4/4b/
Gelenke_Zeichnung
01.jpg/250pxGelenke_Zeichnung
01.jpg
Gliding joint:
The gliding joint, which is also called a plane joint, consists of two flat surfaces that slide
over each other to allow movement, but not any circular movement. These types of joints
are found in the foot between the tarsals and in the hand among the carpals.
Gliding joint in the
foot
http://www.shockfamily.ne
t/skeleton/GLIDING.JPG
Nicholas Lai
10TJ
Ms. Bolton
Saddle joint:
This saddle joint is also a mix of convex projection and concave depression ends of bones
like a hinge bone except that the bones are more wrapped together, like a man riding a
horse. The two ends sticking out represent the legs of the jockey. The best example of
this saddle joint is the carpal joint of the thumb.
Thumb saddle joint
http://www.shockfamily.
net/skeleton/SADDLE.JP
G
Saddle joint
http://www.heumann.org/b
ody.of.knowledge/a8/rdts4
5.gif
Pivot joint:
A pivot joint is formed by a pivot-like process turning within a ring, or a ring on a pivot,
the ring being formed partly of bone, partly of ligament. This allows rotation movement.
Example of a pivot joint is the neck.
Pivot joint
http://upload.wikimedia.or
g/wikipedia/commons/thu
mb/4/4b/Gelenke_Zeichnu
ng01.jpg/250pxGelenke_Zeichnung01.jpg
Neck pivot joint
http://www.dkimages.com/discover/pr
eviews/940/672504.JPG
Condyloid joint:
Like a ball and socket joint, an ovoid end of one bone is placed into an elliptical cavity,
except that it does not provide rotational movement. An example of this is in the wrist.
Condyloid joint
http://upload.wikime
dia.org/wikipedia/co
mmons/thumb/4/4b/
Gelenke_Zeichnung
01.jpg/250pxGelenke_Zeichnung
01.jpg
Wrist Condyloid
joint
http://tbn0.google.com
/images?q=tbn:byr_krmmHoXjM:http:/
/bp2.blogger.com/_fJy
ruZw6hV8/SJNIa_Wu
rpI/AAAAAAAAACc/
oOVeq6zOw40/s400/1
2%2BCondyloid%2BJ
oint.jpg
Nicholas Lai
10TJ
Ms. Bolton
Bibliography
Elbow Joint. (n.d.). Retrieved October 24, 2008, from www.myelbow.com/
Joints. (n.d.). Retrieved October 24, 2008, from http://www.mnsu.edu/emuseum/biology/
humananatomy/skeletal/joints.html
Wikipedia. (n.d.). Pivot Joint. Retrieved October 24, 2008, from Wikipedia Web site:
http://en.wikipedia.org/wiki/Pivot_joint