Ascaris
Ascaris is a genus of parasitic nematode worms known as the "giant intestinal roundworms". Some species typically infect pigs, while others, affects human populations, typically in the sub-tropical and tropical areas with poor health conditions that allow for ascaris worms to infect human beings. Its digestive tract ingests food, breaks macromolecules into their subunits, and allows for the absorption of glucose and amino acids. This animal has some a mouth structure for the ingestion of food that is connected to a tube, which passes through the body of the worm and terminates at an anus, where undigested waste products are excreted. The ascaris' digestive tract includes one muscular structure to ensure that food moves through the tract in the proper direction. Finally, it includes an intestinal region in which absorption of small molecules take place, such as gulcose and amino acids.
Pinworm
The pinworm, also known as the threadworm or seatworm, but most formally known as the Enterobius vermicularis, is a very common intestinal parasite that infect humans, mostly children. Enterobiasis refers to the disease associated with the pinworm infestation in the body. Pinworms are the most common type of roundworms found in the USA. They are parasites that feed off of the human body to survive and reproduce. The pinworm's eggs pass through the digestive tract in the body they infect, where they hatch in the small intestine to become the larval stage. Pinworm larvae then travel from the small intestine to the large intestine, where they attach to the intestinal wall. About two to six weeks after the eggs have been swallowed, adult female pinworms migrate from the large intestine to the rectum, where they exit from the anus to lay numerous eggs on nearby skin. The adult pinworms then return to the large intestine, where they most likely decay and die, but the new eggs then become active within a few hours and live for about three weeks, until a new generation of eggs are born.
Hookworms
The hookworm is a parasitic nematode that lives in the small intestine of its host, which may be in a mammal such as a dog, cat, or human. Two species of hookworms commonly infect humans and are very deadly to the human body. Hookworms are much smaller than the larger roundworm, such as Ascaris (on top of the page) , and the complexity of tissue migration and obstruction so frequently discovered with roundworm infestation are less frequently found in hookworm infestations. The highest risk of hookworm infection and infestation is anemia. The hookworms suck blood voraciously out of the human body and damage cells within the body. However, the blood loss in the body is not visibly apparent. Like other nematodes, hookworms have a full digestive system, with a separate office for food indigestion and waste excretion from the body. The pseudocoelom body cavity lacks the muscles of coelomate animals that force food down the digestive tract, so hookworms depend on internal and external pressures and body movement to move food through their digestive tracts to survive.