Human Digestive System : An Overview - Practice Questions & MCQ

Why do we need food?

• Food is one of the basic requirements of all living organisms
• Food is needed to provide energy and immunity.
• Food is oxidised in the presence of oxygen to release the energy by a process called as aerobic respiration
• The major components of our food are Carbohydrates, Proteins and Fats.
• Vitamins and minerals are also required in small quantities
• Food provides energy and organic materials for growth and repair of tissues. 
• The water we take in plays an important role in metabolic processes and also prevents dehydration of the body
• Biomacromolecules in food cannot be utilised by our body in their original form
• They have to be broken down and converted into simple substances in the digestive system
• This process of conversion of complex food substances to simple absorbable forms is called digestion
• It is carried out by our digestive system (Alimentary canal)
• It is done by mechanical and biochemical methods

• Biomacromolecules in food cannot be utilised by our body in their original form. They have to be broken down and converted into simple substances in the digestive system. This process of conversion of complex food substances to simple absorbable forms is called digestion and is carried out by our digestive system by mechanical and biochemical methods.

• The human digestive system consists of the alimentary canal (Gastrointestinal system) and the digestive glands (alimentare means nutrition)

• The GI tract or alimentary canal starts with the mouth and proceeds to the oesophagus, stomach, small intestine (duodenum, jejunum, ileum), and then to the large intestine (caecum, colon, rectum) and terminates at the anus.

• The digestive glands include the salivary glands, pancreas and liver, and accessory organs of the gastrointestinal system that contribute materials to the small intestine.

• The function of the digestive system is to break down the foods we eat, release their nutrients, and absorb those nutrients into the body. 

The Human Digestive System is shown in the diagram below :