Life Process

Life Process

The process occurring in the body of living beings that keeps them alive is called life process. Respiration, excretion, digestion, reproduction etc are some of the examples of life process.

1) Respiration 

The process of oxidizing food to release energy is called respiration. Some respiratory organs are skin, trachea, spiracles., gills, lungs, etc. There are two types of respiration. They are

i) External respiration

ii) Internal respiration

* External respiration
The process of taking in oxygen and releasing carbondioxide is called external respiration. It is also called breathing.
* Internal respiration
The process of oxidizing food to release energy is called internal respiration. It is also called cellular respiration as it occurs inside the cells. During this process energy is released for different activities. 
* Aerobic respiration 
The type of respiration in which food is completely oxidized by the help of oxygen is called aerobic respiration. More energy is released in aerobic respiration.
* Anaerobic respiration
The respiration which take place in the absence of oxygen is called an aerobic respiration. Less energy is released in anaerobic respiration.
* Cellular respiration 
The type of respiration which occurs inside the cell to oxidized the food to release energy is called cellular respiration.

2) Digestion

The process of breaking down food inside the body is called digestion. There are two types of digestion. They are 
i) Intracellular digestion: The type of digestion that occur inside the cell is called intracellular digestion. It occurs in unicellular organism.

ii) Extracellular digestion: The type of digestion which occur outside the cell is called extracellular digestion. It occurs in multicellular organism like human beings.

Digestive system
Those organs which helps in digestion are called digestive system. Organs involved in digestive system are mouth, food pipe, throat, large intestine, small intestine etc. It consists of two main parts. They are:
* Alimentary canal: It is a long tube from mouth to anus. It is about nine meter long. It consists of mouth, intestine, anus etc.
* Digestive glands: It is the gland which produce different digestive juices in our body. It helps to digest food easily. Some digestive glands and their secretion are given below:
i) Salivary gland: It produce saliva and present in mouth.
ii) Gastic gland: It produce gastic juices and hydrochloric acid and present in stomach.   
iii) Bile gland: It produce bile juice and present in liver.
iv) Pancreas: It produce pancreatic juice and present in duodenum.

Digestion in Human body

In the human body food is digested in alimentary canal with the help of digestive juices. The digested foods are absorbed by villi in small intestine and undigested materials passes through large intestine and stored in rectum for digestion through anus.
3) Excretion: The process of throwing access amount of waste materials from our body is called excretion. 
* Excretory organs: The organs which helps in excretion are called excretory organs. Plants do not have special organs for excretion.
Some excretory organs are: Lungs, skin, large intestine, small intestine etc.
4) Urination: The process of releasing waste material from our body in the form of urine is called urination. 
Urinary system: The group of organs that separates excess water, minerals, salt, uric acid and urea from the blood in the form of urine is called urinary system. Some organs which involves in urination are kidney, urethra, uterus and urinary bladder
Urinary system of human beings: The kidneys filter the urine from the blood which gets collected in urinary bladder. When the urinary bladder is filled about two third, urine is thrown out through urethra.