Webster's New World Medical Dictionary

colitis, universal
Ulcerative colitis that involves
the entire colon (large intestine).
collagen
The principal protein of the skin, ten-
dons, cartilage, bone, and connective tissue.
Collagen is an essential part of the framework of the
design of our various body tissues.
collagen disease
A disease that damages colla-
gen or other components of connective tissue. For
example, dermatomyositis and systemic lupus ery-
thematosus are collagen diseases.
collagen injection
The practice of injecting col-
lagen into a part of the face or body (often the lips)
to make it larger. The effects are long-lasting but not
permanent. Collagen injections are usually done by
plastic surgeons.
collapsed lung
See 
atelectasis.
collarbone
A horizontal bone above the first rib
that makes up the front part of the shoulder. Also
known as the clavicle, the collarbone links the
breastbone (sternum) with the scapula, a triangular
bone in the back of the shoulder. One end of the
collarbone connects to the sternum, forming one
side of the sternoclavicular joint. The other end of
the collarbone connects to the scapula, there form-
ing one side of the acromioclavicular joint.
collateral 1
In anatomy, a subordinate or acces-
sory part.
2
A side branch, as of a blood vessel or
nerve. After a coronary artery occlusion, collateral
vessels often develop to shunt blood around the
blockage.
collateral knee ligament, lateral
A ligament that
straps the outside of the knee joint and provides sta-
bility and strength to the knee joint. Abbreviated LCL.
collateral knee ligament, medial
A ligament
on the inner side of the knee joint. The medial col-
lateral knee ligament adds stability and strength to
the knee joint. Abbreviated MCL.
colon
The long, coiled, tubelike organ that
removes water from digested food. The remaining
material, solid waste called stool, moves through the
colon to the rectum and leaves the body through the
anus. Also known as large bowel and large intestine.