factor, rheumatoid An antibody that is measurable in the blood. Rheumatoid factor is commonly used as a blood test for the diagnosis of rheumatoid arthritis. Rheumatoid factor is present in about 80 percent of adults (and a much lower proportion of children) with rheumatoid arthritis. It is also present in patients with other connective tissue…
factor VIII A coagulation (clotting) factor. Classic hemophilia (hemophilia A) is due to a deficiency in factor VIII activity. Also known as antihemophiliac factor (AHF) or antihemophiliac globulin (AHG). Human factor VIII concentrates as well as recombinant (laboratory-produced) factor VIII are administered in the treatment of hemophilia A. See also hemophilia A.
factitious disorder See Munchhausen syndrome.
facio-genito-popliteal syndrome See popliteal pterygium syndrome.
facies Face.
facial nerve paralysis Loss of voluntary movement of the muscles of one side of the face due to abnormal function of the facial nerve. Paralysis of the facial nerve causes a characteristic drooping of one side of the face, inability to wrinkle the forehead, inability to whistle, inability to close an eye, and deviation of…
facial nerve The seventh cranial nerve, a nerve that has fibers both going out and coming in (both efferent and afferent fibers). The facial nerve supplies the muscles of facial expression. See also facial nerve paralysis.
facial canal introitus The entrance to the facial canal, a passage in the temporal bone of the skull through which the facial nerve (the seventh cranial nerve) travels. In anatomy, an introitus is an entrance that goes into a canal or hollow organ.
facelift A surgical procedure that is designed to make the face appear younger by pulling loose facial skin taut and tightening and repositioning the underlying facial musculature. Excessive skin and/or fat may be removed during the procedure. Supplemental procedures—including necklift, blepharoplasty (eyelid surgery), autologous fat injection, forehead lift, and browlift; chemical or laser peel; and…
face, masklike An expressionless face with little or no sense of animation; a face that is more like a mask than a normal face. Masklike face is seen in a number of disorders, including Parkinson’s disease and myotonic dystrophy. Also known as masklike facies.
Fabry disease A genetic disease caused by a mutation in the GLA gene, resulting in a deficiency of the enzyme alpha-galactosidase A, also known as ceramide trihexosidase. This enzyme is essential to the metabolism of a fat compound known as globotriaosylceramide. Without alpha-galactosidase A, this fatty substance accumulates in the walls of blood vessels, leading…
F 1 Chemical symbol for the element flourine. 2 Abbreviation for Fahrenheit. 3 The symbol for the coefficient of inbreeding. See also coefficient of inbreeding.