The shape of the worm is maintained by internal hydrostatic pressure, controlled by an osmoregulatory system. On solid media the worm crawls on one side, with the alae contacting the substrate. The body wall muscle cells are arranged into four cords running from the pharynx to the tail, two dorsally and two ventrally. The nervous system includes a large anterior ganglion called the nerve ring and a smaller ganglion in the tail. Dorsal and ventral nerve cords run posteriorly from the nerve ring to the body wall muscles.
Sensory neurons run anteriorly from the nerve ring to the sensory organs in the head.
In nematodes muscle cells send processes to and synapse with motor neurons rather than vice versa, as in other animals. C. elegans feeds through a muscular bilobed pharynx, which pumps fluid into the intestine and crushes ingested bacterial cells as they pass through the second lobe. Consists of two rows of eight cells plus an anterior ring of four, surrounding a central lumen, which connects to the anus near the tail. Each lobe includes a distal ovary and a proximal oviduct and spermatheca. Each spermatheca contains about 150 ameboid sperm in a young adult.