what is the principal organ of alimentary canal for absorption of nutrients. How are these nutrients absorbed

Dear Student ,

The Small Intestine is the principle organ for absorption of digested food and nutrients.

The inner lining of the small intestine has millions of tiny finger-like projections called the villi.
These projections increase the surface area of the small intestine for more efficient food  absorption.
Within these villi, the capillaries absorb nutrients from the digested products of proteins and carbohydrates and lead them into the blood stream.

Following are the mechanisms of absorption of various nutrients, minerals and water:

• • Simple diffusion − Glucose, amino acid, electrolytes such as Cl− follow this method; depends upon concentration gradient

  • Facilitated transport − Fructose and some amino acids are absorbed by this method. Absorption occurs with the help of carrier ion such as Na+.

  • Active transport − Glucose, some amino acids, Na+ follow this method. Absorption is against concentration gradient. Thus, it requires energy.

  • Fatty acids are insoluble; hence first broken into small droplets called micelle, which further reform into small protein-coated fat globule called chylomicron (in intestinal mucosa), which are then transported into lacteals in villi, which finally release them into blood stream.
    
    Regards