The Alimentary Canal

Hey there!

Today we’re gonna be launching into another biology series… This time though, I’m doing something regarding the human body. Thought it’d be awesome to let people understand what exactly goes on in their own bodies!

Without further ado…

What is the alimentary canal?

Now, most people often confuse the alimentary canal with the digestive system. But you’ll realize that in the above diagram a few key organs are missing- like the pancreas and the liver. This is because the alimentary canal is a long tube running from one end of your body to another, wherein the ingested food is directy acted upon. However, organs such as the liver and pancreas never make any contact with food, which is why they aren’t a part of the alimentary canal.

Holozoic Nutrition->

What exactly is holozoic nutrition? When an organism ingests organic compounds from outside its body, that is known as holozoic nutrition. Animals are holozoic, but plants are not. Plants make their own food, using only a few enzymes, gases and sunlight. Animals such as the cow for example, have to physically ingest an organic compound to satisfy its needs.

The Path Food Takes->

Food that enters the body always goes through 5 steps or processes. These processes are- ingestion, digestion, absorption, assimilation and egestion.

Most people think that food simply enters the body and gets digested. But actually, there are five essential steps food undergoes inside the body.


This occurs in the mouth, also known as the Buccal Cavity. Food is simply taken into the body, readying it for the long passage ahead. In multicellular organisms like humans, food is normally taken in through a particular organ- like the mouth. In single-celled organisms, ingestion occurs through a cell membrane.


Digestion takes place in the stomach and parts of the small intestine. Contrary to popular belief, it doesn’t take place throughout the entire canal. In the process of digestion, several enzymes, acids and juices are used to break the food down.


Most absorption takes place in the small intestine. Nutrients obtained from the digested food are absorbed into the bloodstream and the lymph fluid. These nutrients include- amino acids, fatty acids, glycerol etc.


Assimilation occurs throughout the body- not in any single part or organ. It’s basically when all the absorbed nutrients are utilized by cells for metabolic processes, cell division and synthesis of new protoplasm.


Egestion is basically pooping. No, not peeing. Just pooping. Sorry for the grossness overload… If you want to get technical, egestion is when the body rids itself of excess organic material that don’t neccesarily have to be toxic.

That’s it for today. I didn’t add any intense stuff today- just an introduction to what’s coming up next!

Thanks for reading!

Published by girrrrrl_of_two_worlds

hi! just a nerdy girl here. lover of science, english and learning on the whole. spreading knowledge is one of my favorite things to do! nothing in life is to be feared, it is only to be understood. now is the time to understand more, so that we may fear less. ~marie curie

Join the Conversation


  1. You break it up and explain it really well. I wouldn’t have managed that 10 years ago…
    Keep writing these posts. I’d love for some science teachers to find them one day and use them πŸ™‚
    Hey, if you’re ever bored, just an idea, maybe you can take all posts like this one and write it for children to understand.
    I’m seriously in awe!!!

    Liked by 1 person

    1. Awww… Thanks for these words, they’ve truly made my day! Thanks for stopping by and reading!
      Hmm… Yes, that does sound like a wonderful idea. Maybe I’ll do that someday!
      Thanks once again.
      Love always,

      Liked by 3 people

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