Top Ten Powerful Nations 2013 (According to Global Presence). Top Ten Powerful Countries Ranking (2012). NOTE: National Power Index (NPI) 2012 is a comprehensively revised version of the previous National Security Indexes published in Indiaâs National Security Annual Review (INSAR) series since 2002.op Ten Powerful Nations 2013 (According to Global Presence). Top Ten Powerful Countries Ranking (2012). NOTE: National Power Index (NPI) 2012 is a comprehensively revised version of the previous National Security Indexes published in Indiaâs National Security Annual Review (INSAR) series since 2002.
Overview. When you take in food, it's the job of your digestive tract to break that food down into smaller pieces through mechanical digestion, and then break larger molecules into smaller ones through chemical digestion.
Your digestive system breaks the food you eat down into small molecules that your intestines can absorb into the bloodstream. Two separate processes are at work. Mechanical digestion involves the physical breakdown of food into smaller chunks. This is what happens when you chew. Chemical digestion, which is the next phase, breaks food into smaller molecules. Digestive enzymes assist with chemical digestion.