What Is The Key Difference Between A Coelom And A Pseudocoelom

A true coelom originates from a split within the embryonic mesoderm.

The cavity of the coelom is thus bounded by a lining of mesodermal cells called peritoneum. The coelomic cavity is filled with coelomic fluid.

A pseudocoelom arises from the blastocoel at an early stage of embryonic development.

Coelom or true body cavity is lined with peritoneum. Pseudocoelom or false body cavity is partially lined with peritoneum.

The coelom is developed by splitting the mesoderm. The pseudocoelom is developed from the blastocoel of the embryo.

What is the difference between a Coelom and Pseudocoelom?


The coelom originates in the mesoderm and-therefore-is typical of tribalistic animals.

In this group, the metazoan specimens are concentrated that in their embryonic development reflect three layers of tissue: endoderm, mesoderm, and ectoderm.

It is delimited by the mesodermal epithelium called the peritoneum.

It is saturated by the coelomatic liquid, which performs various functions.

This liquid is present in large proportions in the body of the earthworm and is of vital importance for the emergence of cocoons that favor its reproduction.

It is also responsible for the elasticity of your body.

On the other hand, Pseudocoelom in particular is very functional. This serves as a transport between the body wall and the digestive tract.

It distributes nutrients, metabolites, and respiratory gases, and temporarily collects waste products.

As a result of the physiological efficacy promoted by the presence of the coelom, undoubted improvements are seen in the anatomy of the animals.

The body increases in size performs better homeostasis. And more satisfactorily assumes its environmental independence and nutritional variation.

Similarly, the fluid-filled cavity gives freedom to the organs, benefiting physiological processes.

The heartbeat is favored, and reverse peristaltic waves are produced in the wall of the body and the digestive tract.

That has its own muscles.

Why is a Pseudocoelom considered to be a false Coelom?

Why is a Pseudocoelom considered to be a false Coelom

The cavity lined with mesoderm that forms during embryonic development is called a coelom.

It is found specifically between the intestine and the body wall. And is unique to higher animals.

In a certain way, the coelom is a sample of the evolution that some species have had in their respective processes of adaptation to the environment.

Very important organs such as the lungs, heart, digestive system, and others are housed in the coelom.

It is covered by epithelium, that is, a tissue made up of one or more cells joined together.

Thanks to various studies it has been found that it unfolds within the mesoderm and is filled with fluid.

Some describe it as a kind of hydrostatic skeleton, in which there are internal organs, supported by mesenteries.

In adult beings, the coelom remains unstable. It can be preserved in gaps in body structures such as the space between gonads and gonoducts.

Likewise, it can be between the excretory organs (such as nephridia), in the pericardial concavities, and between certain circulatory systems.

Animals that have coelom are called coelomats, while those without it are known as coelomates.

In the latter, the space between the body wall and the internal organs is full of cells.

A pseudocolor is a body cavity that lies between mesodermal and endodermal tissue.

It is, therefore, not completely surrounded by mesodermal tissue.

A “true” coelom is completely surrounded by mesodermal tissue, and can thus be subdivided into compartments.

Pseudocoelom is a fluid-filled body cavity. Tissue derived from mesoderm partly lines the fluid-filled body cavity of these animals.

Thus, although organs are held in place loosely, they are not as well organized as in acoelomate.

And that is the reason why it is considered to be a false coelom.

What is the primary difference between a Coelom and a Hemocoel?

What is the primary difference between a Coelom and a Hemocoel

About Coelom:

  1. Embryologically coelom is the secondary body cavity formed within the mesoderm.
  2. Coelom is lined by coelomic epithelium.
  3. Blood passes from arteries to the capillaries but not passes, into the coelom.
  4. Perivisceral body cavity of most triploblastic animals.
  5. Coelom does not contain haemocoelomic sinuses and haemocoelomic channels.
  6. It communicates with the exterior by gonoducts, excretory ducts, etc.

About Haemocoel:

  1. It never communicates with the exterior.
  2. Haemocoel is the primary body cavity or blastocoel.
  3. Body cavity of some coelomates where blood vascular system is expanded with the reduction of the coelom.
  4. Haemocoel is lined by a basal lamina of epithelial sheet.
  5. Large haemocoelomic sinuses and narrow channels are present.
  6. Blood from the arteries does not pass into the capillaries but flows directly into the haemocoel.

Does Pseudocoelomate have a Coelom?

Pseudocoelomate metazoans have a fluid-filled body cavity, the pseudocoelom, which, unlike a true coelom.

It does not have a cellular peritoneal lining.

Most of the pseudocoelomates (e.g., the classes Nematoda and Rotifera) are small and none possess an independent vascular system.

What are the 3 types of Coelom?

What are the 3 types of Coelom

Delving into the classification of animals according to the presence or not of coelom, it is necessary to have these characteristics:

  1. Cellophane: 

They are those triblastic animals that lack a coelom. They naturally possess mesoderm, but it is solid.

For example, flatworms are helomatous.

  1. Pseudocoelomates: 

Tribalistic animals with a cavity similar to the coelom are centered here. However, it is embryologically distinct because it does not originate in the mesoderm.

This cavity is called a pseudocoelom. The species that have it are called pseudocoelomates or blastocoelomates.

The roundworm Ascaris lumbricoides is one of them.

  1. Celomados: 

This word identifies animals with a true coelom. That is the cavity with internal membranes.

Very simple specimens such as porifers, cnidarians, flatworms, nematodes, and rotifers and among others.

These are exonerated from this group. It should be noted that all chordates are coelominated animals.

Also, mollusks such as slugs and oysters, echinoderms such as starfish and sea urchins, and annelids or earthworms.

What is Pseudocoelom 9?

What is Pseudocoelom 9

Pseudocoelom is the false body cavity that lies between the endoderm of the gut and the mesoderm of the body.

It is also popular as a second body cavity.


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