Introduction to Gastrointestinal tract:
The gastrointestinal tract is a one-of-a-kind system. Despite the fact that people use it on a daily basis, most people only have a basic understanding of what it is and how it works. Food enters the mouth, is digested, and used for energy and nutrients; what cannot be used is expelled from the body. The system is much more complex.
Here in this article we will study different parts of this alimentary canal and will look into their functions as well that you may not be aware of. The GI tract is a complex and fascinating part of your daily life that most people ignore until something goes wrong with it. Make sure that you take good care of it.
Alimentary Canal
Alimentary canal is a long muscular tube that extends from the mouth to the stomach and is part of the digestive system. It extends approximately 9 metres in length.
It includes different organs such as the stomach and intestine. It aids in the digestion of meals and the absorption of nutrients from food.
It contains glands that are related to it. The glands are located outside of the gastrointestinal system and are linked to it through ducts like salivary glands, liver and pancreas.
The layers present in the gastrointestinal system are mucous membrane (mucosa), submucosa, muscularis externa, and serosa or adventitia. The mucosa and submucosa projections enhance the surface area available for absorption. The lamina propria and submucosa possess glands.
Alimentary Canal Parts
A tube that travels through the body in one direction is called the alimentary canal. From the mouth, it extends to the anus. About 9 metres make up the alimentary canal. The mouth, oesophagus, stomach, small intestine and large intestine are examples of continuous muscular tubes that run throughout the body (digestive tract). They are capable of digesting and absorbing nutrients.
Mouth
The mouth is the initial part of the alimentary canal. It includes teeth and salivary glands. The teeth help in the mechanical breakdown of food while the salivary glands release saliva that mixes with food to make it soft.
Pharynx
The pharynx is a tube that connects the respiratory and digestive systems. It is linked directly with the larynx and the oesophagus. It's a muscular tube that runs between the tongue and the soft palate. Nasopharynx, oropharynx and laryngeal pharynx are the three types of the pharynx.
Oesophagus
The oesophagus is a lengthy, thin muscular tube that delivers food from the pharynx to the stomach. It contains a lot of longitudinal folds that facilitate the transfer of food.
Stomach
The stomach is a storehouse as well as a digestive organ with little absorption. The cardia, fundus, body and pylorus are the four primary areas. Mucosa, submucosa, muscularis externa and serosa are the four layers of the stomach.
These layers produce mucus, acid and pepsin, which are mixed with food. The stomach wall has chief cells and parietal cells. Pepsinogen and lipase are found in chief cells. Pepsinogen is a proenzyme that is transformed into pepsin by the stomach's acid pH. Parietal cells help in the formation of gastric acid and release some factors for digestion.
Small Intestine
Duodenum, jejunum and ileum are small Intestine structures. Absorption is one of the functions of the small intestine. The villi help with these activities by increasing the surface area of the gut, allowing for greater absorption. Thus, it is a nutrition absorber. Hormones and chemicals are released into the small intestine by the exocrine liver and pancreas.
Large Intestine
It includes the colon (ascending, transverse and descending colon). The purpose of the large intestine is to accept the soupy digestion, remove the water and convert it to faeces. It is located next to the small intestine.
Rectum
The rectum is the intestine's swollen end section. After food digestion, it stores the waste.
Anus
The anus is the hole and end point of the alimentary canal. The external aperture is known as the anus. Defecation is controlled by layers of the muscle. It has sphincters that help in the excretion of the waste outside the body.
Structure of Alimentary Canal
Alimentary Canal Structure
Digestive System Diagram
The digestive system involves the alimentary canal and some other accessory organs that help in digestion. The alimentary canal is a long hollow tube that helps in food absorption and digestion. The digestive organs are accessory organs which assist the main digestive tract. Teeth, tongue, salivary glands and liver are examples. Food is never allowed to enter through them.
Digestive System Diagram
Flow Chart of Digestive System
Flow Chart of Digestive System
Digestive Process Flow Chart
The mouth, throat and salivary glands make up the oral cavity, which is where early digestion takes place.
Ingestion → Digestion → Absorption → Excretion.
Ingestion involves the uptake of food. It involves the mouth pharynx. Digestion helps in food breakdown in small particles. Absorption occurs in the small intestine. The digested food is absorbed and passed into blood circulation. Excretion helps in the removal of waste material from the body after the complete digestion of the food.
Functions of Alimentary Canal
The alimentary canal has the main function of food digestion and absorption. It has different organs and parts that help in food digestion. Teeth help in the mechanical breakdown of food and the mouth helps in food intake. The oesophagus helps in carrying the food particles to the stomach. The stomach helps in storing and maintaining the pH of the food. The small intestine absorbs food particles and passes them to blood. The large Intestine helps in extra water absorption from undigested food.
Conclusion
Our mouth not only chews food but also warms or cools it to a temperature suitable for digestion. The food travels through the oesophagus from our mouth to our stomach in about 7 seconds. Over 500 different types of bacteria live in our digestive tract. While many of them are beneficial, they can be extremely dangerous if they spread to other parts of the body.
Food is digested and absorbed in the body with the help of the gastrointestinal tract. The organs and part of this tract help in the digestion of food. The stomach intestines are important parts and the main digestion and absorption occur here. The above articles help us to understand the structure and function of parts of the alimentary canal. It will be useful to clear concepts about food digestion in the body.
FAQs on Gastrointestinal Tract
1. What are Gastrointestinal Tract Diseases, and How Do They Affect You?
Among the illnesses of the gastrointestinal tract are:
Constipation: Inconsistent or partial bowel movements are referred to as constipation. This is caused by a lack of fiber in one's diet.
Irritable Bowel Syndrome (IBS) is a condition in the intestines. This is a condition in which the colon muscle contracts more often than it would in a healthy person. Bloating, stomach aches and cramps, diarrhea, and other symptoms are common.
Colon Cancer- Colorectal cancer is a kind of cancer that starts in the big intestines and affects the elderly. It starts out as non-cancerous aggregates. These aggregates develop into cancer over time. Surgical, chemo, and radiation treatment are all options for treatment.
2. Define the term anus?
The hole at the termination of the alimentary tract is known as the rectum or anal aperture. Feces, also known as forages, is the process of unprocessed or wasted foods excreting through the intestines. The round muscle or rectums that ring the anus govern the retention and release of fecal waste. The muscles of the outer anal canal are free, whereas the muscle of the internal urethral sphincter is reflexive. Actually, the anus is the terminal section of the gastrointestinal system. Thus, the anus is one of the most important parts of the human body for the proper functioning of the digestive system. It can also be seen in the digestive system diagram and the structure of the alimentary canal.
3. Define Alimentary Canal?
The alimentary canal is one of the essential parts of the gastrointestinal tract. It is a long, continuous muscle tube that goes throughout the abdomen, covering approximately 8 to 10 meters in length. It is accessible on both sides, with mouths on the front and the perineum on the back. It is accountable for meal digestion. It divides it up into small chunks and serves the digested meal to be absorbed.
4. Why does the stomach not digest itself through HCl and its gastric juices?
The alimentary canal includes the stomach. In the lumen, it secretes HCl. HCl aids in the activation of enzymes that aid in the digestion of food. HCl is a powerful acid that can destroy the stomach walls, yet the stomach defends itself against it. Large volumes of mucus protect the stomach wall. The mucosa is a mucus-secreting layer of the stomach. Mucus is a thick, sticky substance that coats the stomach walls and protects them from acid.
5. Define mechanical and chemical types of digestion.
Mechanical digestion usually involves physically breaking down food substances into smaller particles so that chemical digestion can take place more efficiently. Mechanical digestion begins with the physical act of mastication in the mouth (chewing). Food is broken down by the specialised teeth as it is cut by the incisors, torn by the cuspids, and ground by the molars.
Whereas, chemical digestion is responsible for further degrading the molecular structure of ingested compounds by digestive enzymes into a form that can be absorbed into the bloodstream.
6. What are the different enzymes used in the digestion of food, their location and the products they form?
Nutrient | Enzymes used | Where Enzyme Made | Part of Digestive System in which digestion occurs | Product |
Carbohydrate (Starch) | Amylase | Salivary glands Pancreas Small Intestine | Mouth Small Intestine | Simple Sugars (Glucose) |
Protein | Protease | Stomach Small Intestine | Stomach Small Intestine | Amino Acids |
Lipid (fats and oils) | Lipase | Pancreas Small Intestine | Small Intestine | Fatty Acid and Glycerol |
