Alimentary Canal and Its Parts – Imaluop

Hi, today we are going to discuss a part of our digestive system alimentary canal and its parts. Our digestive system starts from our mouth which we use to take food and ends to anus through which the undigested waste materials goes outside of our body.

Different enzymes and chemicals related to digestion reach the digestive tract where our food molecules break down into simple organic molecules for easy absorption by our circulatory system.

Both digestion and absorption of digested material occurs in elementary canal and then the undigested waste is processed further to expel them outside.  

Organs of Our Alimentary Canal: 

Different organs in our digestive system are open into the alimentary canal and our alimentary canal also has different parts – mouth and oral cavity, oesophagus or food tube, bag like muscular stomach, small intestine and large intestine.

Different chemical reactions occur in different regions of the alimentary canal to complete the digestion process. Now we will discuss all the parts of the alimentary canal and their functions in digestion of food one by one. 

Mouth: The Starting Point of Elementary Canal: 

Our alimentary canal starts from our mouth and an opening for taking food inside of our body is bordered by the upper lip and lower lip. Our mouths are open into the oral cavity and food is transferred from mouth to oral cavity. 

Oral Cavity: 

Our oral cavity is like a small chamber which starts from our teeth. Other major parts of our oral cavity are tongue and palate digestion of food start from here. 

Palate: 

It is present on the roof of our oral cavity which helps chewing large food pieces by pressing them towards the tongue and teeth. Its front part is bony hard palate while its backward part is soft palate. 

Tongue: 

It is a muscular flappy part which helps us to take the taste of food and hold the food again palate during chewing. Taste buds present on the tongue allow us to understand the taste of food and a portion of saliva is open near the tongue. 

Teeth: The Chewing Machine of Our Digestive System: 

Teeth help us to chew hard food, cut large food pieces into small pieces, tear tough food for better digestion. Our teeth are two types of milk teeth and permanent teeth, thecodont because our teeth are embedded into the jaw socket, different structures or heterodonts.

Anatomy of our teeth show it has three embedded parts of teeth in the jaw socket root, embedded in the gum neck and outside of the gum exposed part crown. Different types of teeth perform different types of function like – canines for tearing tough food, incisors for cutting food into small pieces, premolar for chopping food and molar for chewing food.  

Pharynx: 

Food pipe and windpipe open together in the pharynx but to prevent the food particles from entering into the windpipe there is a flap like structure epiglottis. 

Oesophagus or Food Pipe: 

Pharynx opens into a long muscular tube, oesophagus or food pipe through which food transfers from oral cavity to stomach in the form of small food bolus. Circular muscle form gastroesophageal sphincter which controls the food passage from oesophagus to stomach near the junction of oesophagus and stomach. 

Stomach: 

Oesophagus opens into a broader muscular bag like organs stomach where gastric juice mixed with food for digestion. Now we will discuss the four parts of the stomach and their functions in digestion. 

Cardiac Part: 

 The part of the stomach near the heart to which the oesophagus opens is known as cardiac part and here the gastroesophageal sphincter present. 

Fundus Part: 

It is a dome shaped part of the stomach which is filled by air and digestion does not occur here. 

Body Part: 

It is the main part of the stomach which is the main place for protein digestion. 

Pyloric Part: 

Stomach ends in the pyloric part which opens into the duodenum part of the small intestine and is guarded by a sphincter pyloric sphincter. 

Small Intestine: 

It is the longest tubular part of our alimentary canal which starts at duodenum and ends in ileum. It has three distinct parts duodenum, jejunum and ileum which we will discuss one by one below. 

Duodenum: 

It is the first part of the small intestine which looks like a ‘C’ in shape and hepatopancreatic ducts are open into duodenum. 

Jejunum: 

Middle part of the small intestine which opens into the next part of the small intestine ileum. 

Ileum: 

Ileum is a highly coiled tubular part of the small intestine which opens into the large intestine. 

Large Intestine: 

Large Intestine is the place for major absorption of digested simple organic molecules and it has three parts- caecum, colon and rectum. 

Caecum: 

Large intestine starts from a small pouch like part caecum which is a shelter for many symbiotic microorganisms. Vestigial organ vermiform appendix attached to the sac like caecum of our large intestine. 

Colon: 

Four parts of colon accommodate nicely in our abdominal cavity – ascending colon, transverse colon, descending colon and sigmoid colon.  

Rectum: 

It is the last part of our large intestine which opens in anus which store undigested waste materials for some time and expel it from our body after a regular interval of time.

Reference: Alimentary Canal and Its Parts

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