Human Nutrition

Human Nutrition Notes

Nutrition :- To derive energy from food called nutrition.

Food :- Sum total of all nutrient called as food.

Nutrient :- The substance which gives energy called as nutrient.

Types of Nutrients :-

1. Energy giving Nutrient
2. Body Building Nutrient
3. Protective Nutrient
4. Organic Nutrient
5. Inorganic Nutrient
6. Micro-Nutrient
7. Macro-Nutrient
8. Other Nutrient

Steps in nutrient

1. Ingestion :- The act of taking food inside the body.

2. Digestion :- The breakdown of complex organic substance to simpler one.

3. Absorption :- Digested
food are absorbed by blood called as absorption

4. Assimillation :- Digested food becomes the part of protoplasm.

5. Egestion :- Undigested food thrown outside the body.

Digestive System :- 

Those system carries the process of digestion called as digestive system.

Digestive system are divided into two types

1. Alimentary Canal
2. Associated Digestive Gland

Alimentary canal

It is the first visceral organ to evolve. it is the tube responsible for conversion of intracellular mode of digestion to extracellular mode. It is about 8.3m from mouth to anus.

Mouth :- An opening of digestive tract where the food is received.


Teeth :- 

Types of teeth :- 

1. Incisors
2. Canines
3. Premolar
4. Molars 

Dentition :- dentition pretends to development of teeth and their arrangement in the mouth. It account the characteristics arrangement kind and number of teeth in the given species at a given age.

Homodont dentition :- All teeth in the jaw alike E.g. - Alligator

Heterodont dentition :-  Teeth difference in general appearance throughout the mouth
E.g. - Human

Different Classes of Teeth

1. Deciduous Teeth :- These are temporary or milk teeth which are erupt in earlier stages of life.

2. Permanent Teeth :- They are stronger than the milk teeth and processed more longer period.

Tongue :- Highly muscular structure containing voluntary muscles.

               Rest upon hyoid bone and attached to the floor of buccal cavity by connective tissue fold called fernulum linguae. It possess the taste buds. It help in testing the food, process of speech, etc

Pharynx :- 

It is the meeting point of respiratory tract and digestive tract.

Oesophagus :- 

It conduct the food from pharynx to stomach

Presitalsis :- 

Rhythmic contraction and relaxation of oesophagus.

Oesophagus carries the food with the help of Presitalsis.

Stomach :- 

It shows the process of digestion. It is a J dedicated sac.

1. Cardiac Stomach :- The part of stomach where the oesophagus open.

2. Fundus Stomach :- The middle portion of the stomach.

3. Pyloric Stomach :- The distal end of stomach.


Small Intestine :- Absorption of digested food.

1. Duodenum :- C-shaped structure containing foliate villi.

2. Jejunum :- Thick walled, vascular, middle part of small intestine. Its diameter is about 4 cm.

3. Illeum :- Thin-Walled, longest part of small intestine.

Large intestine :- Reabsorption of water and salt.

1. Caecum :- Pouch like structure, wall contain prominent lymphoid tissue.

2. Colon :- It has three longitudinal bands called as taeniae cell and self small pouches called haustra.

3. Rectum :- Terminal part of large intestine and digestive track.

Anus :- Egestion of food.

Egestion :- It is define as the undigested food thrown outside the body called as  Egestion.

Associated digestive gland

Salivary gland :- It produces serous cell and mucous cell.

Digestive Glands 

It includes salivary glands, gastric gland, liver, pancreas, and intestinal glands.

1. Pancreatic glands

2. Gastric gland :- They are microscopic, tubular gland formed by epithelium of the stomach.

Liver ( Gall bladder )

--- Largest gland present inside the body.
--- They produce Bile Juice.
--- Bile Juice make food alkaline.
--- Liver store glycogen. ( excess amount of sugar )
--- liver are playing role in synthesis of vitamin.

Hormones of Digestive System

Gastrin :- To stimulate the production of HCL

Secretin :- It produces sodium bicarbonate and selection for production of pancreatic juice.

Chochlecystokinin :- It stimulate the production of pancreatic juice.

Gastric inhibtitory protein (GIP) :- To stop the secretion of HCL.

Absorption and Assimilation

Digested food or absorbed by the blood with the help or through microvilli called absorption.

       The digested food are become the part of protoplasm called as Assimilation .

Nutritional Disorder :- 

1. Kwashiorkor :- Protein energy             malnutrition .

Symptoms :- Slender legs, Weak posture, Poor development of body .

Causes :- Deficiency of protein .

Treatment :- Supply of protein .

2. Marasmus :- 

Symptoms :- Poor development of body .

Causes :- Deficiency of protein .

Treatment :- supply of  protein .

3. Vomiting :- Injection of stomach content through the mouth. this is reflex action is controlled by omentum centre located in the main deula oblongata.

4. Indigestion :- 

Causes :- Overdiet

Post a Comment

0 Comments