is a parasite that feeds primarily on the blood of its host by living in
the hosts heart and arteries. Like all other nematodes, Dirofilaria
immitis has a complete digestive track with a mouth and an anus.
Even thought the diet of nematodes varies greatly, the digestive system
is fairly uniform throughout the phylum. As food, blood in the case of
Dirofilaria immitis, enters though the mouth it goes to the
muscular pharynx, which pumps food from the mouth to the intestine. The
intestine is long and travels the length of the body to the anus, where
waste is excreted. Food is broken down in the intestine by the release
of digestive enzymes that are produced in the epithelial cells that line
the intestine. Digestion starts out extracellularly, but then is
completed intracellularly (Winnipeg 2006). As for respiration and
circulation in nematodes, there is none. All nematodes lack respiratory
and circulatory systems.
picture is a picture of blood at a microscopic level, which is the
primary means of nutrition for Dirofilaria immitis. The
picture was taken from Wikipedia.org and it is in the public domain
because it is from work done by the U.S. Federal Government.