The Tube - monstrous size. Elephantiasis is treatable in...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
The Tube-within-a-tube Body Plan: Phylum Nematoda Humans contract Trichinella (the roundworm that causes the disease trichinosis, illustrated in Figure 26) by eating raw pork containing encysted larvae. Mature female adults burrow into the wall of the small intestine. Live offspring are carried by the bloodstream to the skeletal muscles where they encyst. Religious dietary injunctions against eating pork may in part be a reflection of the prevalence of this disease in the Middle East.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
. Filarial worms cause various diseases. Dirofilaria , shown in Figure 27, causes heartworm in dogs, and is a common filarial worm in temperate zones.
Background image of page 2
Elephantiasis, a disease associated with tropical Africa, and is also caused by a filarial worm that utilizes mosquitos as secondary hosts. Adult worms reside in and block lymphatic vessels. This results in limbs of an infected individual swelling to
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: monstrous size. Elephantiasis is treatable in its early stages but not after scar tissue has blocked lymphatic vessels. The phylum Nemertea include approximately 650 species of marine ribbon worms. Ribbon worms have a distinctive eversible proboscis stored in a rhynchocoel. When the walls of the rhynchocoel contract, the proboscis extends out of the body. The proboscis is a long, hollow tube that can be everted and shot outward through a pore located just above the mouth. It is used primarily for prey capture, and for defense, locomotion, and burrowing. This phylum is included as the organisms are also triploblastic. Several of the fossils from the Cambrian-aged Burgess Shale are interpreted as ribbon worms, and some extremely long worms have been found in the Mediterranean (up to 100 feet long) and in the ocean under the Antarctic ice shelves...
View Full Document

Page1 / 3

The Tube - monstrous size. Elephantiasis is treatable in...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online