• Question: can you tell me how the digestive system works

    Asked by 573heab47 to Billy, Louise, Naomi, Rachel, Urvashi on 10 Mar 2015.
    • Photo: Naomi Green

      Naomi Green answered on 10 Mar 2015:

      Hi there!
      I’m afraid I can’t help you. I am a mechanical engineer by training which means I have no medical training at all. I learn what I need to about the human body in order to solve the problems I am faced with. In my case I work on the spine and also joints so I probably know just as much as you about the digestive system. As a biomedical engineer I am interested in designing devices which solve problems, not understanding the whole human body and how it works, or how to treat people with illnesses. I am currently working on the design of an implant which replaces an intervertebral disc in the spine. The implant is made up of a kind of ball and socket joint which allows the patient to move. Over time the artificial joint will wear away and the implant will have to be replaced, which means another operation for the patient. So I am studying the use of different materials, like metals, plastics and ceramics and testing which material will last the longest to minimise the number of operations a patient will need in their lifetime. So I spend a lot of my time designing and manufacturing things and testing them. I don’t actually deal with the “body” very much at all!

    • Photo: Urvashi Danookdharree

      Urvashi Danookdharree answered on 16 Mar 2015:


      The digestive system is a biological system in your body than starts from the mouth to end in faeces 😉 All start when you put food inside your mouth, you have saliva which starts some of the digestion using the salivary enzymes. At the same time your taste buds in the tongue allows oneself to taste the food. This then goes into the oesophagus which is a tube connecting the mouth to the stomach. The alternate contraction and relaxation of the smooth muscles in the oesophagus, allow the food to go down to the stomach.

      There, there is acid which digests the food further and allow the food to go to the small intestine. Pancreatic enzymes and bile from the gall bladder (In the liver) are then released into the first part of the intestine (Duodenum) which further digests the different categories of food present. For example, the bile is intended to break down larger fat molecules into smaller fat molecules.

      This process continues in the middle part of the intestine which then distribute the appropriate vitamins, minerals, proteins, fat and water to the blood vessels which then distribute to the whole body.

      The remaining toxic stuffs and fibres which were not digested goes into the large intestine whereby they are converted into faeces in order to be excreted.

      I tried to summarise a very long and detailed process in this answer. I hope it is understable and it helped you 🙂

      Urvashi 🙂

    • Photo: Louise France

      Louise France answered on 16 Mar 2015:

      Hey 573heab47 🙂

      Urvashi answered the question really well, so i want to put a bit of a medical engineering spin on things.

      Did you see in the news lately that an artificial pancreas was implanted into a 4yr old who was living with type-I diabetes? He is the first person in the world to receive the medically engineered implant that helps to regulate and pump insulin around his body!

      The average waiting time for a pancreas transplant on the NHS is around 18 months. This is because not many people donate, and also the donor needs to have the same blood type as the patient, and also the size of the pancreas is important (you cant give an adult pancreas to a child). Once implanted, if the body doesnt reject the donated pancreas within the first 6 months (which is highly likely) then there is an 85% success rate. With the artificial pancreas, there is very little chance of the body rejecting it, and there is no waiting time as it is an off-the-shelf product. Imagine how many people could be helped with an implant like this!

      Here is a link to the story published in The Guardian newspaper:

      Hope you find this interesting! 🙂