explain human digestive system so as to explain the phenomenon of absorption assimilation and egestion
Answers
As the food gets broken down into smaller and simpler particles, it has to get absorbed into the bloodstream. It is only through the blood and circulatory system that the digested food reaches various cells and tissues. Blood coming from the digestive organs carries simple sugars, glycerol, amino acids, and a few vitamins and salts to the liver. The liver stores and processes these substances. They are also detoxified here. It delivers the nutrients to the rest of the body, as and when needed. This entire process is summed up as Absorption and Assimilation.
The process through which the end products of digestion are absorbed into the blood or lymph from the intestinal mucosa is called as Absorption. This process occurs either by the passive, active or facilitated transport mechanisms in the body. The small intestine is the organ where absorption occurs. It is specially adapted to carry out this function.
- Starting from mouth till the anus is called alimentary canal. The digestion of food starts from mouth only. When the food is chewed the saliva secreted by the salivary amylase mixes up with food and helps in rolling the food swiftly. From mouth the food is transferred to stomach by oesophagus ( food pipe). Stomach is the largest part of human body. In stomach mucus is the protective layer which helps in protecting the acidic medium in human body.