classical

classical /clas·si·cal/ (klas´ĭ-k'l) classic.

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classical, classic

the first recognized form of the item; serving as a standard model or guide. See also classical conditioning, east coast fever.

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classical conditioning

see conditioning.

classical pathway

one of the two pathways of complement activation, initiated by antigen-antibody complexes and involving C1, C2 and C4. It leads to activation of C3 and the terminal pathway. See also alternate complement pathway.

classical swine fever

now the universally accepted name for hog cholera and different from African swine fever (ASF). A highly infectious disease of pigs caused by a pestivirus and characterized in its classical form by high fever, lassitude, purple discoloration of abdominal skin, conjunctivitis and nervous signs including circling, incoordination, tremor and convulsions. Most affected pigs die at 5 to 7 days with a characteristic petechiation under the kidney capsule—turkey egg kidney. There is a second form, characterized by nervous signs and caused by a strain of virus of lower virulence. Other syndromes caused by low virulence strains are reproductive inefficiency and congenital defects including myotonia congenita. Also known as congenital trembles.