Webster's New World Medical Dictionary

popliteal
Referring to the back of the knee.
For example, the popliteal fossa is the hollow
behind the knee.
popliteal fossa
The hollow behind the knee.
popliteal pterygium syndrome
An inherited
condition that is characterized by a web (ptery-
gium) behind the knee. Facial abnormalities in
popliteal pterygium syndrome are cleft palate (with
or without cleft lip), pits in the lower lip, and
fibrous bands in the mouth. Genital abnormalities in
popliteal pterygium syndrome are underdevelop-
ment of the labia majora, malformation of the scro-
tum, and failure of the testes to descend into the
scrotum. Patients have an extensive web running
from behind the knee down to the heel, malformed
toenails, and webbed toes. The disorder is inherited
in an autosomal dominant manner and is due to
mutation of the interferon regulatory factor 6 gene.
Also known as facio-genito-popliteal syndrome.
pork tapeworm
See 
Taenia solium.
porphyria
One of a variety of hereditary diseases
that are characterized by abnormalities in the reac-
tions needed for the production of heme, an essen-
tial substance for the body, resulting in increased
formation and excretion of chemicals called por-
phyrins. Most porphyrias affect the skin or the nerv-
ous system. Attacks may range from mild to severe.
Besides having abdominal and nerve pain, the
patient may suffer rapid heartbeat, mania, muscle
cramps, muscle weakness, breathing problems, hal-
lucinations, and coma. Acute attacks are often pre-
cipitated by the use of certain drugs, such as
barbiturates, sulphonamides, and birth control
pills; alcohol use; hormonal changes during men-
struation or pregnancy; dieting or fasting; and infec-
tions. One type of porphyria, acute intermittent
porphyria, may have affected members of the House
of Hanover in England, including “Mad” King
George, who may have suffered attacks of porphyria
instead of being “mad.”