“Digestion is the process  oof breakdown of complex molecules into simple molecules”. Digestion process takes place in alimentary canal. From mouth to anus pathway we called alimentary canal. Digestion pathway  is mouth, oesophagus, stomach, small intestine, large intestine, anus. These all are participate in digestion. Mouth is also part of the digestion.*30% of the carbohydrates digestion takes place in it. Mouth contains teeth, saliva, salivary gland. Salivary gland contain ptyalin, amylase which helpful for the carbohydrates digestion. Four types of teeth are  present in our human body. They are incisors, canines, pre molars, molars. These four types teeth are helping for the cutting, tearing, mastificate   the food. Saliva helpful for the easily movement of the food into oesophagus, and saliva also contain the immunity cells. To kill any  foreign material enter into food. Saliva is very essential for  easily  movement of the food. Food partially digested in mouth.  partially digested food we called chyme. That food enters into oesophagus, then enters into stomach by peristalsis movements. In stomach food stores 4-5 hours. When food enters into stomach, food mixes with Hcl. Hcl kill any harm ful germs or foreign material enter into our body. Protein digestion also takes place in our stomach. Then that food enters into small intestine, major digestion and absorption takes place. Small intestine is the largest part in our alimentary canal.largest contain villi. Villi helpful for the absorption of the food material. Villi contain lymphatic tissues.  To get immunity from lymph. Then the food enters into large intestine. There is no longer function in this, some salts, minerals, and water absorbed. Unwanted waste material converted into faecal matter. That faecal matter enters into anus. Anus that passed out. In this way digestion of food takes place.  REASONS FOR DIGESTIVE DISEASES.. Excess eating  of junk foods cause obesity.  migraine, heart related diseases. Some food contain excess of  carbohydrates. One of the main reasons for the stomach pain,  stomach ulcers is the “fasting ”. Because  in our stomach  contain Hcl. Hcl is the gastric juice acidic in nature. Hcl is release particular time  in our body. If  you are fasting  that time Hcl releases  in our stomach. Due to empty stomach stomach will not tolerate high acidity. This causes formation of holes in our stomach. That we called ulcers. Eat expired products will effet on the health. Ea foo i n un hygiene places. Cause  malaria, fevers. Etc. Vomiting caused by reverse peristalsis movement. Vomiting also caused by  uun hygiene conditions. Kwashiorkor is a digestive related disease, excess carbohydrates in our food. Cause this disease. Marasmus is a disease lack of protein and carbohydrates in our food. So, lot of people suffering from lack of food. So don't waste food. Donate food..