Leeches :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Leeches   Ã‚  Ã‚  Ã‚  Ã‚  The leech is a segmented worm that in all actuallity has a very vivid life. From being used by doctors to just being blood-sucking parasites, the leech is a true wonder of the mind.   Ã‚  Ã‚  Ã‚  Ã‚  The leech has a series of ring-like segments that make up its body structure. They maybe from 2 to 20 centimeters long and have the ability to shorten or lengthen their bodies. They mostly come in colors of black, red or brown, sometimes with stripes or spots. They are extremely sensitive to touch, temperatue, and drying out. Also, they have clusters of cells on the front end thatare light-sensative, almost like eyes. Leeches usually live in dark, damp areas such as the bottoms of lakes, jungels, or shallow streams. Finally, the leech is a Hermaphrodit, containing bot male and female sexual reproductive organs.   Ã‚  Ã‚  Ã‚  Ã‚  With a sucker at both ends of it's body, the leech usually lives as a parasite, feeding upon the blood and tissue of other animals, or on decaying plant and animal materials. It has a mouth centered on the front sucker with teeth in some cases. Leeches, that are parasites, attach to their victim with the front sucker, create a wound, then suck out blood with, usually, both suckers. Blood-sucking leeches give out a liquid substance called Hirudin. This chemical prevents the blood from thickening and enables the blood to be easily sucked by the leech.   Ã‚  Ã‚  Ã‚  Ã‚  Doctors once used leeches, or what they called medicinal leeches, to remove blood from patients in an orderly manner. The first clinical use of leeches in this fashion occured approximatly 2,500 years ago. Since the leeches bite produces a small cleeding wound ,that mimics a venous circulation in an area of compromised tissue, the leech is particlarly valuable for reconstruction surgery. Special properties of the bite, such as the chemical hirudin, allow continued bleeding for up to 48 hours after the leech