spiro-, spir-, spiri-
(Greek, speira > Latin, spira: coil, coiled; twisted, turning)
The Greek speira refers to anything which is wound or wrapped around something. In the plural, speirai, it includes the twisted folds or coils of a serpent or of a net; therefore, it refers to anything which is coiled, wreathed, or twisted; such as, a coil of a snake.
Careful, there is another spiro- which means "breath of life; breathing, breath".
A nematocyst is a capsule within the specialized cells of certain coelenterates; such as, jellyfish, containing a barbed, threadlike tube that delivers a paralyzing sting when propelled into attackers and prey. Also called, "stinging cell".
2. Formed spirally.
The basilar membrane is a thin layer of tissue which is covered with mesothelial (flattened cells) which separates the cochlea from the scala (canals) tympani in the ear.
The cochlea is that part of the internal ear which is concerned with hearing.
There are other "coil" words at this helico- unit.