C. Elegens Digestive Tract

 In this diagram we see the major parts of C. elegens which comprise three major functional groups: (1) digestive system, (2) reproductive system, and (3) neural system. C. elegens clearly has evolved to serve the dual biological imperatives of (a) living to reproduce and (b) procreating. It does so with the the added benefit of a neural system connected to a muscle cells to enable mobility. In this regards, C. elegens is functionally no different than us humans. 

The digestive system, consisting of about 100 cells, is divided into three distinctive regions: (1) pharynx, (2) intestine and (3) rectum. This also parallels that of humans.

The pharynx is the feeding system of C. elegens, an encapsulated organ that has a simple anatomy, consisting of 20 neurons and 8 muscle types constituting three functional parts, the corpus, the isthmus and the terminal bulb.

 The corpus sucks the food in through the mouth, the isthmus crushes it, and the posterior bulb grinds it to aid in digestion. A valve between bulb and intestine controls passage of food to the intestine. The human pharynx performs the same functions.

The intestine itself consists of 9 pairs of cells which from a tube through which food passes and which absorb nutrients as it passes though the tube. They correspond to the intestinal epithelial cells in humans and perform the same function.

At the rear end of C. elegens are 6 pairs of cells which form the rectum. The first pair of cells function as value and correspond the the sphincter in humans.The next three of cells function as a rectal gland which secretes chemicals for unknown purposes  but humans have have rectal glands as well as all other mammals.Then comes three pairs of excretory muscle cells with another pair forming the anal opening itself.

Yes, humans are truly a worm just like C. elegens with an opening through our bodies for obtaining nutrients from the environment around us. We both are like an elongated donut with a mouth at one end, an anus at the other and an intestine in between.