The immune system and infection

Le ganglion lymphatique is the lymph node, and the noun in front of that adjective is one of the cleanest traps in medical French. Both languages took the word from the same Greek ganglion, which named a knot-like swelling under the skin, and then handed it to different parts of the body. English gave it to the nervous system: a « ganglion » is a cluster of nerve cell bodies, as in the basal ganglia or the dorsal root ganglion. The one sense that survives outside anatomy is the soft swelling that grows on a wrist or a tendon sheath, which a surgeon removes. Nobody writing English calls a lymph node a ganglion. French went the other way. Un ganglion, with no adjective at all, is the lymph node, and j’ai des ganglions is what a patient with a sore throat says about swollen glands. The nerve sense is still there, but it has to be marked: le ganglion nerveux. So the adjective in ganglion lymphatique is a clinical formality for a French reader and, for an English one, the whole of the information.