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Earthworm Anatomy 1. Segmented BodyEarthworms room classified in the phylum Annelida or Annelids. Annelidain Latin means, “little rings.” The human body of the earthworm is segmentedwhich looks like many little rings joined or unify together. Theearthworm is do of about 100-150 segments. The segmented body partsprovide important structural functions. Segmentation can assist theearthworm move. Each segment or section has muscles and also bristles calledsetae. The bristles or setae assist anchor and also control the worm whenmoving with soil. The bristles organize a ar of the worm firmlyinto the ground while the other part of the human body protrudes forward. Theearthworm offers segments to either contract or relax individually tocause the human body to lengthen in one area or contract in various other areas.Segmentation help the worm to be versatile and solid in that is movement.If every segment relocated together without gift independent, the earthwormwould it is in stationary.
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2.Digestive system The digestive device is partitioned into numerous regions, eachwith a details function. The digestive system is composed of the pharynx,the esophagus, the crop, the intestine and also the gizzard. Food together assoil enters the earthworm’s mouth whereby it is swallowed by the pharynx.Then the floor passes through the esophagus, which has calciferousglands that relax calcium carbonate to escape the earthworm’s human body ofexcess calcium. After that passes with the esophagus, the food movesinto the crop where it is stored and then eventually moves into thegizzard. The gizzard supplies stones that the earthworm eats to grind thefood completely. The food moves right into the intestines as gland cells inthe intestine relax fluids to assist in the cradle process. Theintestinal wall surface contains blood vessels whereby the spend food isabsorbed and transported come the remainder of the body.
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3.Circulatory System an additional important organ system is the circulatory system.The earthworm has actually a closeup of the door circulatory system. One earthworm circulatesblood exclusively through vessels. There space three main vessels thatsupply the blood to organs in ~ the earthworm. This vessels space theaortic arches, dorsal blood vessels, and also ventral blood vessels. Theaortic arches function like a person heart. Over there are 5 pairs ofaortic arches, which have the duty of pump blood right into thedorsal and also ventral blood vessels. The dorsal blood vessels areresponsible for moving blood to the front of the earthworm’s body.The ventral blood vessels room responsible for delivering blood to theback of the earthworm’s body.
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4.Respiratory system Earthworms do not have lungs. Lock breathe v theirskin. Oxygen and also carbon dioxide pass with the earthworm’s skin bydiffusion. For diffusion come occur, the earthworm’s skin need to be keptmoist.Body fluid and also mucous is released to keep its skin moist. Earthwormstherefore, need to be in wet or moist soil. This is one reason whythey usually surface at night when it is perhaps cooler and the“evaporating potential the the air is low.”(www.amonline.net.au/factsheets/earthworms.htm) Earthworms havedeveloped the ability to recognize light even though they can not see. Theyhave tissue situated at the earthworm’s head the is sensitive to light.These tissues permit an earthworm come detect light and not surfaceduring the daytime whereby they could be influenced by the sun.
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EarthwormReproduction Earthworms room hermaphrodites whereby each earthworm containsboth male and also female sex organs. The male and female sex organs canproduce sperm and also egg respectively in every earthworm. Althoughearthworms room hermaphrodites, many need a mate to reproduce. Duringmating, two worms heat up inverted native each other so sperm deserve to beexchanged. The earthworms each have actually two masculine openings and also two spermreceptacles, which take in the sperm from one more mate. The earthwormshave a pair that ovaries that create eggs. The clitellum will kind aslime tube approximately it, which will fill with an albuminous fluid. Theearthworm will relocate forward the end of the slime tube. Together the earthwormpasses with the slime tube, the tube will pass end the female porepicking increase eggs. The pipe will continue to relocate down the earthworm andpass end the male pore referred to as the spermatheca which has the storedsperm dubbed the spermatozoa. The eggs will certainly fertilize and the slimetube will certainly close off together the worm moves completely out of the tube. Theslime tube will form an “egg cocoon” and be put into the soil.


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Thefertilized eggs will develop and also become young worms.
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