Digestive system assignment
Unit 8C- Explore the physiology of the digestive system and the use of corrective treatments for
dietary related diseases.
Nutrition and health
Introduction
This is a guide that investigates the anatomy and physiology of the digestive system, sources and
uses of various important nutrients and associated symptoms of nutrient deficiency linked to the
consequences of, and treatments for, dietary related diseases.
The digestion system breaks down food and drinks to give us nutrients and help us to stay healthy.
Our bodies brake down proteins, fats, carbohydrates, vitamins, minerals, and water for them to be
absorbed and used by our body for energy, growth, cell repair.
Heathy diet
A healthy diet as defined by the NHS consists of “eat at least 5 portions of a variety of fruit and
vegetables every day (see 5 A Day) base meals on higher fibre starchy foods like potatoes, bread, rice
or pasta. have some dairy or dairy alternatives (such as soya drinks) eat some beans, pulses, fish,
eggs, meat and other protein.”.
Importance of a healthy diet
A healthy diet is extremely important to a person’s overall health this can range from physical
health, mental health, and also neurological health. A healthy diet protects you against many chronic
noncommunicable diseases such as heart disease, diabetes and even cancers.
What each nutrient in a healthy diet is needed for
The nutrient needed for a healthy diet include the following:
Vitamins
Vitamins are needed in a healthy diet to heal wounds, increase the immune system, repair cellular
damage. Vitamins perform hundreds of tasks throughout the body, but they are the most noticeable
implications of vitamins.
Minerals
Minerals are needed in a healthy diet to build strong bones and teeth.
, Protein
Proteins are needed in a diet to help the body repair cells and make new cells; they are also
important for growth and development in youth and pregnant women.
Fats
Fats are important because they are essential to give your body energy and to support cell growth,
they also have a help protect vital organs from external damage.
Water
Water is the most important nutrient due to it being involved in all body functions: such as
regulating body temperature.
Carbohydrates
Carbohydrates should typically be the body’s main source of energy (due to it being broken down
into glucose to be absorbed into the blood stream)
Fibre
Fibre is needed to help digestion and prevent constipation for people. Also reports claim that there
is strong evidence consuming fibre can lower risks of heart disease, strokes, type 2 diabetes, and
bowel cancer.
What do they do and what role does it have for digestion
Mouth
When you chew, you begin the digestive process. Salivary glands produce saliva, a digestive juice
that moistens food and allows it to pass more quickly through your oesophagus into your stomach.
Saliva also produces an enzyme that starts the breakdown of starches in your food. The main
function of the mouth(for digestion) is to breakdown food into smaller part so that the stomach can
fully break down it. Mechanical digestion in the oral cavity involves the teeth grinding food into
smaller fragments, known as mastication. Chemical digestion in the mouth is minor, but it requires
salivary amylase and lingual lipase, all of which are present in saliva and this help break down
starches in the food that we consume.
Pharynx
The pharynx, also known as the throat, is the passageway that connects the mouth and nose to the
oesophagus and larynx. The pharynx serves both the respiratory and digestive systems by receiving
air from the nasal cavity and food as well as water from the oral cavity. During digestion, the pharynx
allows ingested solids and liquids to pass through the oesophagus, or gullet, and transports oxygen
to and from the trachea, or windpipe. The pharynx does not break down any food but only
transports ingested solids through to the oesophagus so therefore, it is neither mechanical digestion
nor chemical digestion due to the breaking of food is required to perform both digestions however
the variable is how they are broken down in mechanical and chemical digestion.
Oesophagus
The oesophagus is a muscular tube that connects the stomach to the stomach. It is the tube that
connects your mouth to your stomach for digestion. The oesophageal walls squeeze together as you
swallow food. This helps the food to travel through the oesophagus and into the stomach for
digestion. The role that the oesophagus has an important role in digestion due to without it no food
could get digested and absorbed for energy. No digestion takes place in the oesophagus therefore it
is neither mechanical digestion nor chemical digestion.
, Stomach
The stomach is like a mixer that churns and pulls all the tiny balls of food down in smaller and
smaller pieces. This is done with the aid of tight muscles in the stomach walls and gastric juices from
the walls of the stomach. The stomach in digestion is majorly important due to without its people
would only be able to consume little food a day (not enough to survive). The role of the stomach in
the digestive system is to break down the food even more into tiny particles so it can be absorbed it
does this by mixing the food with stomach enzymes. These enzymes help to break down food into a
shape that can be absorbed. In the stomach there is both chemical and mechanical digestion.
Mechanical digestion occurs when the stomach is churring the food into absorbable particles and
chemical digestion occurs when the food mixes with the enzymes to break it down further secreted
in the stomach lining.
Small intestine
The small intestine, also known as the small bowel, is a 20-foot-long hollow channel that connects
the stomach to the beginning of the large intestine. The small intestine breaks down food in the
stomach and consumes a large portion of the nutrients to be used for numerous reasons mainly
energy. The role of the small intestine is the most important process of the digestive system, this is
due to it absorbing all of the nutrients that a person gets from the food into their bloodstream. The
majority of digestion performed by the small intestine is chemical digestion however, mechanical
digestion would still occur but only at a minor extent.
Large intestine
The large intestine is far broader than the small intestine. The large intestine's purpose is to absorb
water and salts from content that has not been digested as food and to eliminate any waste
materials that have remained from the small intestine and this is also the role for the large intestine
in digestion. The large intestine is majority mechanical digestion unlike the small intestine. This is
due to the ileocecal sphincter regulates the movement of chyme from the ileum into the cecum,
which starts mechanical digestion.
Food tests
Starch test
To test for starch, you would add a couple drops of iodine into your sample that you are testing and
if it were a positive test, it would turn a blue-black colour, however for a negative test the substance
would stay a brown colour due to it not reacting to any starch and only having the colour of the
iodine itself which is originally brownish. As you can see our test was positive for starch.
Protein’s test
To test for proteins, you would add the liquid sample into the testing tube, but the sample
has already been prepared by a lab technician. Then we would add approximately 2 cm³ of
the biuret solution into the test tube which holds the sample. And then we would repeat the steps
above however with de-ionized water this is in order to prepare a negative control you would also
add albumin to prepare a positive control. After all that you would shake the mixture consistently for
a minute or so and then leave it to rest for 5 minutes. If the substance contained proteins
the substance would turn pink/lilac to a deep purple/violet colour. A negative test colour
would turn a blue colour (these can vary). As you can see our test was a positive test due to
the colour change.
