What is the fate of the digested substances that move into blood from the intestine?

If energy has to be obtained from food it has to be oxidised. For this purpose respiration has to go on. During inhalation oxygen moves across the walls of the alveoli and enters the blood. From here it enters the red blood cells and gets distributed throughout the cells of our body. At the same time carbon dioxide from the blood moves into the alveoli of the lungs and breathed out during exhalation. Nutrients in the cells get oxidized and energy is released.

Where is the energy stored?

Which system do you think will remove the excess salts from our body?

What would be the path of salt removal from gut to the out side of our body?

During respiration we breathe continuously by inhaling and exhaling air. This is an involuntary process controlled by the medulla oblongata of the autonomous nervous system (ANS). During respiration the movement of inter costal muscles diaphragm moves the ribs cage inflating and deflating the lungs. Air containing more of oxygen enters the blood stream through lungs. If the oxygen has to reach the tissues it has to be circulated through blood. How does this process go on?

Hence the process of digestion which is a complex process that involves many organs and organ systems. Though digestion occurs in the food canal, co-ordination of respiration and blood circulation is necessary otherwise oxidation of food and transport of substances which is vital for energy releasing process will not take place. This may lead to the shut down of systems interdependent on each other.

The food taken by us has to be broken down into constituent substances for proper digestion, assimilation and energy releasing processess.