UTILIZATION OF NUTRIENTS

 

Foods, when ingested in the body, release the nutrients contained in them, for the sake of giving energy, for the various body processes, maintenance of body tissue or reproduction.

The entire process that the food undergoes from the time it is eaten to its excretion is known as metabolism of food.


This building up and breaking down of substances is a continuous process in the body and requires a constant supply of nutrients.

Nutrients are obtained from food by the process of metabolism that takes place via: 

The digestive system is specially developed for this purpose. It begins at the mouth and comprises the food pipe (oesophagus), stomach, small and large intestines, and it ends at the anus. The liver, gall bladder, salivary glands and pancreas are associated with the process of digestion. 

                                                 

The function of each of the organs of the digestive system in brief are:

1. Mouth. Chewing the food (mastication) and mixing with saliva coming from salivary glands.

2. Oesophagus. Passage for the food from mouth to stomach.

3. Stomach. Storage and churning of food along with various secretions such as hydrochloric acid, pepsin, rennin.

4. Small intestine. Made up of three parts, duodenum-a U-shaped loop of the small intestine receives pancreatic and bile juices; jejunum and ileum complete digestion and absorb the digested product through the villi.

5. Pancreas. It is a diffused gland in the loop of the duodenum. It secretes digestive enzymes and also insulin which is the hormone responsible for carbohydrate metabolism.

6. Liver. One of the largest glands in the body as well as an important one, secretes bile which is stored in the gall bladder. The liver also stores sugar in the form of glycogen, the fat-soluble vitamins, etc.

7. Gall bladder. It is the storage gland for bile secreted by the liver. Bile has several functions.

(a) It is strongly alkaline, hence, the acidic food passing into the duodenum on mixing with bile becomes alkaline. This change from the acidic state to alkaline is essential for the action of enzymes in the small intestine.

(b) It prevents growth of bacteria.

(c) It emulsifies fat so that action of lipase is effectively brought about.

8. Large intestine, Colon and Rectum. The reabsorption of water and certain B vitamins take place in the large intestine. The waste products pass down into the colon and are stored in the rectum till they pass out as stools from the anus.



Context from:

Nutrition and dietetics Textbook

The Digestive System and How It Works (National Institute of Diabetes and Digestive and Kidney Diseases Journal) 


Location: Bengaluru, Karnataka, India

Comments

Post a Comment

Popular posts from this blog

Science of Lentils

Image
  Protein, carbohydrate, fiber, vitamins, and minerals are all abundant in lentils. They are essential to human diet because they reduce the need for meat by providing an alternative to animal proteins.  Lentil seeds are rich in iron, calcium, phosphorus, magnesium, vitamin A, and vitamin B, and they also include 1-2% fat, 24-32% proteins, and 59% carbs.   Legumes with a high average protein content and fast cooking times are the most desired legumes in many areas. There are various ways to prepare lentils: soaking, boiling, fermenting, frying, sprouting/germination, and dry-heat techniques. It can also be used medicinally and for processed lentils and lentil snacks. Because lentil straw has very little cellulose, it is also a highly appreciated animal feed. Conversely, the vegetative components of lentils can be utilized as green manure.  Fermentation: The amount of lactic acid will increase as the batter continues to ferment. Tip: Putting tea bag into the pressur...
Read more

Carbohydrate Metabolism

Image
The primary energy source for living cells is glucose. Since glucose is linked to all of the main pathways involved in the metabolism of carbohydrates, it is the key molecule in this process. Energy is obtained from glucose, which is produced from non-carbohydrate precursors and stored as glycogen to be released as needed. The liver is essential for controlling and regulating blood sugar levels. Liver can therefore be adequately regarded as a glucostat monitor. Major pathways of carbohydrate metabolism. The important pathways of carbohydrate metabolism are listed                                                                       Overview of glucose metabolism.                             ...
Read more