Dictionary

orthostatic hypotension See hypotension, orthostatic.

orthotic A support, brace, or splint used to support, align, prevent, or correct the function of movable parts of the body. Shoe inserts are orthotics that are intended to correct an abnormal or irregular walking pattern, by altering slightly the angles at which the foot strikes a walking or running surface. Other orthotics include neck…

OS The left eye (oculus sinister), as opposed to the right eye (oculus dexter).

os sacrum The large, heavy bone at the base of the spine. The os sacrum is symmetrical and roughly triangular in shape. The female sacrum is wider and less curved than the male sacrum, to permit easier childbearing.

Osgood-Schlatter disease An inflammation of the patellar tendon and surrounding soft tissues at the point where the tendon attaches to the tibia in children. Osgood-Schlatter disease is caused by repetitive stress or tension on a part of the growth area of the upper tibia (the apophysis). The disease may also be associated with an avulsion…

OSHA Occupational Safety and Health Administration.

Osler node A small, tender, transient nodule that develops in the pads of fingers and toes and on the palms and soles. Osler nodes are a highly diagnostic sign of bacterial infection of the heart (subacute bacterial endocarditis).

Osler-Rendu-Weber syndrome See hereditary hemorrhagic telangectasia.

orbital In anatomy, pertaining to the orbit, the bony cavity that contains the eyeball.

orbital ridge The bony ridge beneath the eyebrow.

orchidectomy The surgical removal of one or both testes.

orchiectomy Orchidectomy.