Earthworm Anatomy

The earthworm biology basically consists of an elongated cylindrical body that is metamerically segmented. Functionally regionated into various parts ie.

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External anatomy of earthworm.

Earthworm anatomy. Anatomy of an earthworm. Locate the clitellum which is on the anterior end of the worm. After studying its external anatomy we will dissect the earthworm to explore its internal anatomy.

Along the way organic matter is pushed into the crop where food is stored and then into a gizzard where tiny pebbles previously eaten by the worm are used to grind food for further digestion. A mouth at the front end of the earthworm leads to what amounts to a long tube where the organic matter and dirt from the worms diet pass through until it exits the other end. Their digestive system is made of the mouth pharynx crop gizzard intestine and anus.

Earthworms have 5 aortic arches while Humans have one heart. Internal and external anatomy of an earthworm. Internal Earthworm Anatomy.

Externally a thin non-cellular cuticle covers the body wall of the earthworm. The skin of segments fourteenth fifteenth and sixteenth is swollen and pale in mature worms to form a saddle shaped structure called clitellum or cingulum. The openings near the clitellum are the genital setae.

These segments are covered in setae or small bristles which the worm uses to move and burrow. Earthworms use the prostomium to see their environment as earthworms have no eyes ears nose or hands. LOCOMOTION Begins at the anterior end and travels posteriorlythe earthworm travels 25cm in one minute circular muscle contract and longitudinal muscle relax and body become thinner and longer and producing peristaltic waves along the bodythe wave begins in front and.

At the very front of an earthworm you will find the pharynx. It respirates through its skin. The body of Pheretima is nearly circular in cross-section and varies from 7 to 8 inches 18-19 cms in length.

What is the internal anatomy of an earthworm. Earthworms are segmented invertebrates with sections called annuli. Some people even use earthworm castings as garden fertilizer.

Underneath this cuticle a layer of the epidermis followed by two muscle layers and coelomic epithelium inner layer is sheathed. Earthworms get oxygen through their skin while Humans breathe in and out for oxygen. Examine your earthworm and determine the dorsal and ventral sides.

These terrestrial worms typically dwell in soil and moist leaf litter. Humans do not have a crop or a gizzard. Earthworms are commonly found in soil eating a wide variety of organic matter.

Earthworms are invertebrates while humans are vertebrates. Examine your earthworm and determine the dorsal and ventral sides. They exhibit a tube-within-a-tube body plan are externally segmented with corresponding internal segmentation and usually have setae on all segments.

In this Biology lab we will examine an earthworm. This is followed by an epidermal layer two muscle layers and inner coelomic epithelium. Humans have a spine instead of a ventral nerve chord.

The openings toward the anterior of the worm are the sperm ducts The openings near the clitellum are the genital setae. The epithelium consists of a single layer of glandular columnar epithelium. The earthworm is made of about 100-150 segments.

Phylum Annelida Class ClitellataThis video was made by the teaching assistant C. There is a small tongue-like lobe just above the mouth called the prostomium see figure 1. An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida.

Earthworms push the pharynx from inside their mouths to grab hold of things. Pheretima posthuma the common species of earthworms is usually given to kids for their biology experiments while studying the anatomy of an earthworm. External Anatomy of Earthworm.

Ernst for the students of. This organic matter includes plant matter living protozoa rotifers nematodes bacteria fungi and other microorganisms. Earthworms bodies are made up of ringlike segments called annuli.

The epidermis has columnar epithelial cells which are present in a single layer. Mouth and buccal chamber pharynx esophagus gizzard stomach and intestine. The first segment of the earthworm the peristomium see figure 1 contains the mouth.

They pull food into their mouths and then soak it in saliva. There are also some secretory gland cells present. Annelida in Latin means little rings The body of the earthworm is segmented which looks like many little rings joined or fused together.

Locate the dark line that runs down the dorsal side of the worm this is the. Complete straight tube throughout the length of the body from mouth to anus. Mouth constitutes its anterior and anus its posterior openings receptively.

Locate the mouth of the worm on the far anterior end of the wormThe openings toward the anterior of the worm are the sperm ducts. They occur worldwide where soil water and temperature allow. The general colour of the body is brown but the dorsal surface is darker.

It has a central and a peripheral nervous system. Locate the two openings on the ventral surface of the earthworm. The body of the earthworm is covered externally by a thin noncellular cuticle.

Segmented Body Earthworms are classified in the phylum Annelida or Annelids. Earthworms are examples of non chordates that live within burrows of composting moist soil.

Diagram Earthworms Annelids Invertebrates