Anatomy Of A Roundworm

Since roundworms have no respiratory or circulatory systems they use diffusion for respiration and circulation of substances around their body. They are a cylindrical shape and males are smaller than females.

Hookworm Wikipedia

Tapeworms utilize diffusion to absorb nutrients from the hosts digestive system.

Anatomy of a roundworm. Given that both are parasitic worms which of the following reasons best explains why the tapeworm is flat. Both male and female anatomy are examined roundworms are a nice example of animals that display sexual. While the reported number of nematoda species greatly varies there are at least 12000 official species.

They are a cylindrical shape. Even though they are thin and round they are actually bilaterally symmetric. The body is contained within a tough elastic cuticle which in many species forms elaborate structures useful for identification.

Also called nematodes roundworms are highly diverse cylindrical shaped worms that live in a wide array of terrestrial and aquatic environments. The cuticle is the closest thing a roundworm has to a skeleton and in fact the worm uses its cuticle as a support and leverage point for movement. These muscles are all aligned longitudinally along the inside of the body so the nematode can only bend its body from side to side not crawl or lift itself.

They exhibit a simple but complete digestive system and a large reproductive system. The nematode body is cylindrical elongated and smooth with no limbs protruding such as is seen in the common garden worm though generally on a smaller scale. Roundworm is the common name for members of the phylum nematoda.

Longitudinal canals that function as the excretory system of the roundworm releasing nitrogenous wastes in the form of ammonia and urea pseudocoelom body cavity lined on the inside by a layer of gastrodermis and on the outside by a layer of mesoderm. Whereas the rest of the body is bilaterally symmetrical the head is radially symmetrical with sensory bristles and in many cases solid head shields radiating outwards around the mouth. Ascaris worms are a very common roundworm that can live in the intestines of horses pigs and humans.

Compare the anatomy of the tapeworm image c to the anatomy of the roundworm image d. Roundworms are psuedocoelomate which means they have a body cavity between their mesoderm and endoderm layers. The flatworm has a gastrovascular cavity with only a single opening that functions as both mouth and anus.

The mouth has either three or six lips which often bear a series of teeth on their inner edges. Long muscles lie just underneath the epidermis. Roundworms are one of the simplest animal groups that have a complete digestive system.

The roundworm has a complete digestive tract with two separate openings for the mouth and anus.

Roundworm Anatomy