Introduction

Introduction to Digestive System

The digestive system is like a long pipe in your body where food travels to be broken down.

Digestive system is also known as the alimentary canal or tract, and it is responsible for breaking down complex food substances.

It is the pathway that changes the food we eat into tiny bits.

This system turns heavy food into very small pieces that can enter our blood.

It converts these substances into simpler components that can be absorbed into the bloodstream.

This means it changes food into a form that the blood can carry around.

This work is very important so that our body cells can use the food to grow.

This process is crucial for assimilation in the cells and tissues, which supports growth.

If the food does not enter our cells, we cannot grow or have energy.

Definition of Digestion

Digestion means breaking food into small pieces so the body can use it.

Digestion is the breakdown of food into smaller parts that the body can more easily absorb and use.

It is simply turning the eba or bread we eat into tiny liquid-like particles.

Types of Alimentary Tract

There are two main ways the digestive pipe is built in living things.

There are two types of alimentary tracts: the complete and the incomplete alimentary tract.

Some animals have only one door for food, while others have two.

The Incomplete Alimentary Tract

This type of pipe has only one hole for everything.

The incomplete alimentary tract has only one opening to the outside world, which is called the mouth.

This means the same hole used for eating is used for removing waste.

This one hole does two different jobs for the animal.

This mouth serves two main purposes: ingestion (taking in food) and egestion (getting rid of waste).

Food goes in through the mouth, and toilet also comes out through that same mouth.

An example of an organism with an incomplete alimentary tract is a planarian.

The Complete Alimentary Tract

This type of pipe has two different holes, one at the start and one at the end.

The complete alimentary tract has two openings to the outside: the mouth and the anus.

It is like a proper tube where food enters at the top and waste leaves at the bottom.

Each hole has its own special work to do.

The mouth is used for ingestion, while the anus is for egestion.

Eating happens at the mouth, and passing waste happens at the anus.

Examples of organisms with a complete alimentary tract include birds, earthworms, goats, and humans.

How the Complete System Works

In this type of system, every part has a special job to do.

In a complete digestive tract, each part of the system performs different functions and is specialized for its role.

Every station in the pipe handles a different part of the work.

For instance, when we eat yam, our teeth break it down into smaller pieces.

The small pieces of yam are then pushed down a pipe in our throat.

These smaller pieces are then pushed into the esophagus, where a process called peristalsis occurs to move the food along.

Peristalsis is the way the throat muscles squeeze food down.

The food is transported to the stomach, where it is churned and mixed.

From the stomach, it moves to the small intestine, where digestion is completed, and nutrients are absorbed through tiny finger-like projections called villi.

Villi are like tiny sponges in the small intestine that soak up the food into the body.

The remaining material then travels to the large intestine, which absorbs water from the food.

Any leftover waste is eventually passed out of the body through the anus.

It is important to note that when food is ingested, the incoming food does not mix with the undigested waste materials that are already present in the system.

This means new food and old waste stay separate as they move through the pipe.