Trichinella Spiralis
Trichinella Spiralis is a parasitic worm, also known as "pork worm", that is commonly found in undercooked pork products and is one of the most widespread parasites in the world. It infects animals such as rats, pigs, bears, and humans, and is the one of the smallest nematode parasites; it typically measures in at around 1.4 to 1.6 millimeters long. Trichinella Spiralis first infects the intestines, then moves into the bloodstream and infects several muscles. Trichinella Spiralis does not have a formal respiratory system but rather breathes through diffusion. Diffusion is a process in which oxygen enters through the worm's skin while carbon dioxide and other waste products exit from it.