circuit

(serk it) [L. circu’it us]. The round or course traversed by an electric current. The circuit is said to be closed when it is continuous, so that the current may pa through it: it is open, broken, or interrupted when it is not continuous and the current cannot pa through it. h’s c., a series of conditions which must be fulfilled by a bacterium before it is proved pathogenic. The organism must always be found with the disease; it must be capable of forming pure cultures outside the body; these cultures must be capable of reproducing the disease, and the microbes must again be found with the artificially produced morbid proce . short c., a current developed between two branches of another circuit at a point short of the terminals, so that the current does not reach the latter. eircular (serku-lar) (L. circula’ris]. Shaped like a circle; occurring in a circle. eirculation (ser-ku-la’shun) [1,. circula’tio]. Movement in a regular or circuitous course, as, the circulation of the blood. allantoic c¢., circulation in the fetus through the umbilical ve els. collateral c., that which is carried on through secondary channels after stoppage of the principal course. compensatory c. Same as collateral ¢. coronary c., the circulation within the muscular ti ues of the heart. cro c., the Circulation in a portion of the body of one animal of blood supplied from another animal. derivative c., the pa age of blood from arteries to veins without going through capillaries. fetal c., that which is carried on in the fetus, umbilical cord, and placenta. first c., primitive c., that 15 CION IT IS 225 CIR CUM INTESTINAL which conveys nutriment and oxygen to the embryo. greater c. Same as systemic c. le er See pulmonary c. lymph c., the pa age of the lymph through lymph-ve els and glands. placental c. Same as fetal c. portal c., the pa age of the venous blood from the gastro-intestinal tract and spleen through the liver and out by the hepatic vein. pw. nary c., the circulation of the blood through the lungs for the purpose of oxygenation: called also le er ς. sinusoidal c., the flow of blood through pa ages in the ti ues which are lined only with endothelium and have not the structure of arteries. systemic c., the general circulation as distinguished from the pulmonary. vitelline c., the circulation through the blood-ve els ramifying upon the yolk.