Digestive System Of Earthworm, Organs, Anatomy Physiology and History

Earthworms are hermaphrodites, which means they have male and female reproductive parts. Earthworms lay eggs in cocoons. After mating, the egg begins dividing until it’s four cells long. At the specified time, earthworm cells include distinct elements.

Gene expression has gone on so far that cells would not be able to make a full creature and is left to evolve on their own.

In digestion, swallowing is followed by the digestive organs, which are distinguishable from the esophagus since they are ringed by larger ventricles with wide arteries. The crop-gizzard is also partially covered in cream-colored seminal vesicles of the reproductive tract.

Earthworm Anatomy

The earthworm anatomy essentially consists of an elongated, cylindrical body that is metamerically segmented. A thin cuticle, epidermis, and musculature makes up the body wall. The body cavity is a true coelom, as it is lined by the coelomic epithelium.

There are four classes of cells found in the coelomic fluid; phagocytes, mucocytes, rounded nucleated cells, and the chloragogen cells.

The circulatory system for the terrestrial worm is closed type, consisting of blood vessels and capillaries that are distributed all over the body. The plasma and corpuscles comprise the blood, and it has multiple hearts. The earthworm is a hermaphrodite, and reproduction is strictly sexual.

The three kinds of the particular earthworm include pharyngeal, integumentary, and the septal sort. The earthworm is an invertebrate that has an elaborate central nervous system with a very simple brain and nerve cord.

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Earthworm Digestive Tract and Organs

An earthworm turns into a staple muncher as it digests dead and decaying plant and animal matter in the soil. All this it do with mouth, buccal cavity, Esophagus, Larynx, Pharynx, Crops, Gizzard, Intestine, and gizzard.

  • The mouth of an earthworm, also called prostomium, is a circular opening present at the front end of the first segment. The mouth leads to its buccal cavity. Food is ingested through the mouth.
  • Pharynx is a small, swollen, thicker-walled pear-shaped space that takes up only the forthright part of the 3rd organ. It is wider than the pharyngeal cavity and set apart from it using constriction. It has a pharyngeal preputial gland that is situated in the lower end of the secretory orifice of the pharyngeal gland. The pharyngeal gland produces saliva, which consists of the proteolytic enzymes, proteinase, and mu.
  • The esophagus extends from the section between the 5th and 7th ribs to the gizzard without including a gland and disposes of the food pieces that come up from the pharynx. It then reaches the gizzard.
  • The earthworm gizzard is a hard oval, thick-walled, and extremely muscular organ lying in the 8th or 8th-9th segment of the alimentary canal. It is the hardest portion of the food pipe due to the parts of the cuticle on the inner lining.
  • This short, thin-walled, vascular structure is known as the stomach. It lies between the 9th and 14th segments from the ridge and is wider than the esophagus. There is a gland in the stomach that helps to digest nutrients. The stomach leads to the intestine. Saliva produced by the salivary glands in the stomach secretes proteolytic enzymes that aid in digestion of proteins.
  • The intestine is a long and thin-walled tube that extends from the 15th to the last segment except for the anus. The inner lining is ciliated, vascular, folded, and glandular. It is the intestinal lining that is folded to form villi. One villus becomes larger and more developed than the other and runs mid-dorsally from the 27th to the last 25th segment.

Earthworm Digestive System Physiology

Earthworms frequently nourish in various types of organic decompositions, such as decomposing leaves and microorganisms. They typically feed on grasslands or the plants that make up native environments.

During eating, the oral cavity is expanded out by the operation of protractile and retractile muscles, and the food enters the mouth. The meal enters the pharynx via the buccal cavity. The dorsal chamber of the pharynx contains the pharyngeal gland made up of chromophil cells that generate saliva and mucin.

Mucin lubricates the meal and transforms it into soft food while protease changes protein into amino acids. The dehydrated meal moves down the gullet. There, it is crushed by the swell of gizzard muscles.

Food’s ground material goes into the stomach where the breakdown of nutrients by secreting enzymes takes place. Here, the complete breakdown of organic substances into amino acids occurs. In the small intestine, however, the flocculation of undigested food appears and the intestinal tubes create amylase which changes starches into sugars.

Digestion mainly occurs in the intestines and the food it absorbs is transported by way of the villi. The bloodstream carries it by way of capillaries. Afterwards, another reason why it stays in your body is the throwing out of the undigested meal through the anus.

History of Earthworm Digestive System Discovery

In the 1830s, captains Edward Bailey and D. Baker experienced a blast located in Michigan known as the “Tartar Trot,” yet they hadn’t at any time yet connected it to the digestion procedure. That is exactly where Army Surgeon Dr. William Beaumont located it in the year 1822.

In Beaumont’s time, stomach digestion was demonstrated to be strictly chemical, the result mostly of hydrochloric acid in the stomach. This was dismissed only by Beaumont himself. This confirmed his idea of the stomach and ushered in his fame.

How Much Do Earthworm Eat

It is notices that worm can eat equal to their weight and some worms noted to eat half of their weight in a day.

How Much Do Earthworms Weigh

Earthworms weigh between 20-26 grams, also there are some worms seen who overeat and weigh more than their normal weight.


The most essential system for the earthworm is the biochemical system. The prostomium in earthworm has strong lips along with pear-shaped buccal cavity.

There are no jaws or teeth, and the earthworm uses the muscle tissue of the pharynx to break down food that the body uses to obtain energy. The lips then break it down into smaller pieces and use soil particles to grind it to a fine powdered form. Food that has gone through this process is then passed from the mouth to the pharynx.

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