The types of wastes and the excretion process in the human
When we eat, some food is digested, then the blood carries the digested food to all the body cells, The cells consume the digested food to produce the energy and release some useless materials to the blood to be expelled out of the body and these useless materials are called the excretory materials (the cell wastes).
When some food is not digested, This indigested food becomes useless, So it must be expelled outside the body in the form of the solid wastes, There are two types of the wastes that expelled outside the body which are the solid wastes and the excretory materials.
The solid wastes are the indigested food that stored in the large intestine until it passes out of the body, And the excretory materials are expelled out of the body through the excretion process.
The excretion process is the process of getting rid of the excretory materials out of the body, and the excretory materials are the waste materials that produced inside the body cells and the body must get rid of them.
The excretion is the process of removing the cellular wastes, the excretion refers specifically to the elimination of wastes produced by the cellular activity, and it is not removal of undigested food material.
The body must get rid of the excretory materials as they contain the harmless materials that the body can not use them and the poisonous materials that the body must get rid of them.