How do we digest the food we take?

 

 

         

 

 

                    The body needs energy to power its chemical life processes. It also needs raw materials for maintenance, growth and repair. The energy and raw materials are in our food. Digestion is the process of taking in, or eating, food and breaking it down into tiny pieces, small enough to pass into the blood and be carried all around the body. The parts that take in and break down food are known as the digestive system.

 

 

 

 

 

 

 

 

 

INSIDE THE MOUTH

                     The teeth cut off and chew pieces of food into a soft pulp. Saliva (spit) makes the food moist and slippery, for easy swallowing. The tongue tastes the food, to make sure it is not bad or rotten, and moves it around in the mouth, for thorough chewing. The lips seal at the front of the mouth to stop food and drink dribbling out during chewing.

 

 

 

 

TEETH

                     There are four main kinds of teeth. The sharp-edged, chisel-like incisors at the front of the mouth slice and cut pieces from large food items. The taller, pointed canines tear and rip tough food. The premolars and molars at the back of the mouth squeeze and crush the food. Each tooth has a long root that fixes it firmly in the jaw bone, and a crown that sticks up above the soft, pink gum. The whitish enamel covering the crown is the hardest substance in the body.

 

 

 

 

 

 

OESOPHAGUS AND STOMACH

               Swallowed food is squeezed down the oesophagus by wave-like muscular contractions of its wall, called peristalsis. The food enters the stomach, a J-shaped muscular bag. This expands like a balloon to hold about three litres of food and drink. It churns up the food, mixing in its strong digestive juices to break it into smaller and smaller particles. An average meal takes between three and six hours to be digested in the stomach. If the food is bad or unsuitable in some way, peristalsis works in reverse and pushes it up and out of the mouth, a process called vomiting.

                  Two large organs aid the process of digestion. The pancreas gland is wedge-shaped and lies behind the stomach on the left. It makes strong digestive juices that flow along a tube, the pancreatic duct, into the small intestine. These juices dissolve the food further. The other organ is the liver, in front of the stomach on the right. It makes a yellow-green liquid, bile. This is stored in the gall bladder and then added to the food in the small intestine, to help digest fatty foods.

Picture Credit : Google