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Digestion and Absorption NEET Notes

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The concepts of digestion and absorption are among the most crucial topics in NEET’s scope, which touches upon several important topics. Since the chapter is quite extensive, revising it at the last moment may seem challenging.


To remedy this, you can refer to important notes of biology for NEET digestion and absorption for quick and effective revision. It will not only enable you to glance through the important concepts but will also help to identify crucial points of digestion and absorption NEET.


With that being said, let us find out more about these concepts below!


What is Digestion?

It is the process through which complex food is converted into a simpler form to facilitate absorption of nutrients and release of energy in the body.


What is the Digestive System?

The digestive system includes the alimentary canal and digestive glands. The alimentary canal which runs down from the esophagus to the rectum has four layers, namely, serosa, mucosa, muscularis and submucosa.


These following make up the alimentary canal –

  • Mouth.

  • Pharynx.

  • Stomach.

  • Small intestine.

  • Large intestine.


Digestive Glands

These glands play a vital role in digestion. Typically, there are 5 types of glands, and they are as follow –

  1. Salivary glands. 

  2. Gastric Glands.

  3. Intestinal Glands.

  4. Pancreas. 

  5. Liver.


Important notes of biology for NEET digestion and absorption explains these glands and their functions in brief and helps to understand the same effectively.


Digestion of Food

Digestion commences in the mouth where the masticated food gets mixed with saliva. In turn, it creates bolus or small mass of food which moves down the pharynx and esophagus with the help of deglutition or swallowing.


Subsequently, the digestive enzymes present in the alimentary canal get mixed with food and initiates the process of digestion.


These pointers highlight some of the most noteworthy steps in the process of digestion.

  • Chemical digestion commences in the oral cavity with the help of salivary enzymes like lysosomes and amylase.

  • Mucosa layer in the stomach contains gastric glands which have mucous neck cells, peptides of the chief cell and parietal cells. 

  • Mucous cells secrete mucus, while the peptic of chief cells is responsible for secreting proenzyme pepsinogen. Additionally, the oxyntic or parietal cells secrete HCL, which is responsible for converting pepsinogen into pepsin for digesting protein.

  • Bicarbonates and mucus found in the gastric juice lubricates and protects the inner wall of the stomach against the corrosion caused by HCL. 

  • Small intestine releases pancreatic juice, bile and intestinal juice. Notably, the pancreatic juice has inactive trypsinogen, lipases, nucleases, chymotrypsinogen, amylases and procarboxypeptidase.

  • Enterokinase which is an enzyme, activates Trypsinogen into trypsin which subsequently activates other enzymes found in intestinal juice.

  • Bile salts, bilirubin and biliverdin, cholesterol and phospholipids aid the emulsification of fats.


Most digestion and absorption class 11 notes cover these pointers in detail and explain their importance as well. Read through for a better understanding and quality revision.

 

Absorption

This process converts bio-macromolecules into simpler forms in the duodenum and gets further absorbed in the intestine’s ileum and jejunum. Notably, the food is absorbed through diffusion because of the concentration gradient, whereas water is transported because of osmosis gradient.


Subsequently, through assimilation, the nutrients are absorbed and transported to different body parts via blood and lymph.


Read more about absorption and its role in the important notes of biology for NEET digestion and absorption.


Several bacterial, viral, parasitic and protozoan infections are responsible for the inflammation of the intestine and are among the primary causes of digestive disorders.


This table explains the common disorders of the digestive system.


Digestive System Disorders

Sr.No. 

Disorder

Description


Jaundice

More precisely, it is a liver disorder, wherein a large quantity of bilirubin pigment is found in the extracellular fluid. 


Indigestion

It is a common disorder which occurs due to incomplete digestion of food and is often accompanied by acid regurgitation, nausea, pain, heartburn, etc. 


Constipation

It is responsible for irregular bowel movements. 


Diarrhea 

Diarrhea is often responsible for the inadequate absorption of nutrients. 


Vomiting 

Continuous vomiting leads to dehydration. 


A weak digestive system leads to poor absorption of nutrients, which in turn leads to protein-energy malnutrition, especially in children. Two of the most prevalent diseases which occur due to malnutrition include marasmus and kwashiorkor. 

You can find out more about digestive disorder in Class 11 Biology digestion and absorption notes. 


Plan Your Revisions for Better Results!

NEET is the most important stage for students who intend to gain admission in the medical or dental course. It is also considered as one of the toughest entrance exams.


Since success in NEET depends entirely on preparation, it’s time for you to make the most of these last few weeks before the exam. Incorporate smart ways of revision tools and techniques to improve your preparation.


For instance, refer to important notes of biology for NEET digestion and absorption for a quick yet impactful revision. Also, the digestion and absorption NEET notes will ensure that you do not miss out on any relevant topic.


The NEET syllabus for ‘Digestion and Absorption’ is a very vast chapter. It is often better to consult the Important Notes that are available on this topic, for revising before the exams. This makes it easier for the students as all the concepts and all the important points are explained, with the help of solutions , and clearly given in these notes.


These Important Questions are available on Vedantu, and can be downloaded for free.


Conversion of the food particles into smaller forms which nutrirents can be absorbed easily into the body in order to release energy is what Digestion is.


Digestive System consists of a group of organs that work together in order to convert the food that we take into energy that is required for the body. The Digestive System is made up of the gastrointestinal tract along with the additional organs like the liver, pancreas and gallbladder.


The process of digestion involves the Alimentary canal with other accessory organs. Parts of the nervous system as well as the circulatory system plays an important role in the Digestion process, and a combination of the bacteria, nerves,hormones, blood and other organs of the digestive system complete the entire digestive process.


The Digestion process starts with the mouth, then passes through the pharynx, esophagus, the stomach,then the small intestines, large intestines, the rectum and finishes at the anus. And as the food passes through the various compartments of the alimentary canal, the food gets gradually digested.

FAQs on Digestion and Absorption NEET Notes

1. What is the difference between Digestion and Absorption?

Digestion is the process wherein, food particles are converted into a small form which can be readily absorbed by the body to produce energy and for providing nourishment. In case of absorption, nutrients from digested food molecules are absorbed readily by the small intestine. 

2. What are the different Types of Digestive Glands?

There are 5 types of digestive glands – i. Salivary glands, ii. Gastric glands, iii. Intestinal glands, iv. Pancreas, and v. Liver. 

3. Which is the Largest Digestive Gland? Explain Its Function.

The largest digestive gland is the liver, which is located in the abdominal cavity and below the diaphragm. Liver’s primary function is to detoxify metabolites and synthesise protein; in turn, it aids the process of digestion.

4. Explain the Organs involved in the process of Digestion?

The process of Digestion starts with the Mouth, with chewing of the food, where the food is broken into smaller pieces; The Esophagus  the tube behind the windpipe and inside the throat. Muscles here contract so as to enable food to move down. The Stomach to where the food comes down from the Esophagus. The process of Digestion continues where food gets mixed with various enzymes and acids and food gets broken down thoroughly. It then moves down to the Small Intestine,  where most of the vitamins and nutrients that are absorbed from the food gets into the bloodstream. As the food passes through , more enzymes are added to help in the process. Partially digested, food then goes into the Large Intestine where most of the water is absorbed from the waste. At the end, the Rectum

5. What are some common disorders of the Digestive system?

There are various common disorders of the Digestive System for which viral, bacterial and various parasitic infections are responsible which results in intestine inflammation. These are some of the most common disorders, some of which are:


i) Jaundice, which is a liver disorder.


ii) Indigestion, which is caused by incomplete digestion and is usually accompanied by nausea, pain and heartburn.


iii) Diarrhea which happens due to insufficient and inadequate nutrients.


iv) Constipation which happens due to irregular bowel symptoms.

6. Explain the difference between Absorption and Digestion?

When the food we ingest gets broken up into smaller building blocks, we call it Digestion. When the building blocks that are digested go into the bloodstream and go through the Intestines, and later transported to various cells and tissues, and to other organs, we call it Absorption. The chemical and mechanical breakdown of food is Digestion, whereas when nutrients are taken in by the body, it is called Absorption.

7. What is meant by the Digestive Gland?

There are various digestive glands that are present in the human body. The glands help in the secretion through ducts and send it to the targeted organs like the gastric glands, the salivary glands, the liver, the pancreas and also the intestinal glands. The salivary glands are the glands that secrete saliva. The digestive gland helps in tracking certain substances that are necessary and needed for digestion.

8. What is the function of the largest digestive gland?

Liver is considered to be the largest Digestive gland and it is located in the abdominal cavity and just below the Diaphragm. The liver helps to detoxify metabolites and synthesize proteins. The function of the liver is to secrete the bile juice which aids in the emulsification of fats. The main function of the liver includes Filtration, Digestion, Metabolism and Detoxification and the storage of vitamins and minerals.

9. What is the best way to prepare for NEET?

NEET preparation requires a lot of hard work, a lot of dedication, and a great deal of discipline. In-depth, thorough knowledge of the three fundamental subjects required for NEET, like Biology, Physics, and Chemistry is important and required.  Students should be clear about the syllabus and should try and get acquainted with the pattern of expected questions. It is very important to give equal importance to all three subjects, and practice on a regular basis is recommended. Getting Solved Question Papers of previous years developed by experts is highly recommended for succeeding in the NEET.