The structure of the large intestine

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3 day meal plan for a teenage male athlete -

Day 1

Day 2

Day 3


Bowl of All Bran cereal

Half a grapefruit


X2 Boiled eggs with X2 brown toast

Mixed berry smoothie

Fruit with full fat yogurt

X2 brown toast


Salmon Salad

Strawberries, raspberries and full fat yogurt

Baked potato with green salad

Fruit salad

Chicken salad

Seed and nut mix


Chicken and broccoli with brown rice

Mango and pineapple smoothie

Tuna Steak with rice and green vegetables

Beef steak, boiled potatoes and steamed cabbage

Slice of melon

3 day meal plan for a 30 year old expectant mother

Day 1

Day 2

Day 3


Special K with Semi-skimmed milk

X2 brown toast

Orange juice

Cornflakes with semi-skimmed milk

Half a grapefruit

X2 brown toast with boiled eggs

Fresh orange juice

Slice of melon


Tuna Salad sandwich on brown bread


Boiled egg salad

Non-fat yogurt

Baked potato and chicken salad with spinach


Turkey, potatoes and mixed vegetables

Beef stir fry

Chicken and broccoli with rice

Fat free yogurt with strawberries and raspberries

3 day meal plan for an elderly man in hospital

Day 1

Day 2

Day 3



Orange juice

Sardines on toast


X2 poached eggs

X2 White toast


Cheddar cheese sandwich

Boiled ham sandwich

Tuna steak with rice and vegetables


Salmon, boiled potatoes and mixed vegetables

Lamb chop, sweet potato mash and cabbage

Minced beef stew with mashed potatoes

Peaches and rice pudding

  1. The reason for choosing this menu for the young male athlete was to ensure that his diet included as much of the nutritional requirements for the age range but with added carbohydrates so ensure enough energy is provided, and protein to enable the body to build up the body muscles.
  2. In the menu for the expectant mother was done bearing in mind to include B9 where possible to as this helps to prevent any neural defects in her unborn child. It was also important to ensure that she had enough carbohydrates for energy levels to be adequate. This menu meets the advised requirements and has an adequate amount of B9 included.
  3. The choice of menu for the elderly hospital patient was developed with the understanding that due to his age his nutritional requirements were reduced.


  1. An inadequate diet can result in becoming type 2 diabetic. Type 2 diabetes is a condition to where there is a problem with the way in which the body produces and uses insulin; insulin helps the body to move the sugar from the blood to the muscles and cells for energy and storage. There are many reasons as to how this can occur; one of the main causes to this condition is due to obesity (, 2014), this happens due to the release of chemicals that can upset the body’s cardiovascular and metabolic systems (NHS, 2014). It is said that being overweight causes the body to trigger changes to the metabolic system which causes fat tissue to release fat molecules into the blood; this then enters into the cells known as the insulin receptor cells (Bupa, 2013). A person with a BMI of 25 or over is most at risk of contracting type 2 diabetes. If a person is diagnosed with type 2 diabetes it is advisable that the stick to balanced diet including fruit, vegetables, starchy foods, non-dairy proteins and dairy foods (Diabetes UK, 2014).
  2. Atherosclerosis is a serious disorder to which a poor diet can cause; atherosclerosis comes with risk factors for cardiovascular diseases such as peripheral arterial disease, coronary heart disease, strokes and heart attacks. Poor diet contributes to these conditions mainly due to having a high-fat diet, lack of exercise and having high cholesterol (NHS, 2014). Atherosclerosis is a fatty material that begins accumulating in the lining of the artery walls from a young age (British Heart Foundation, 2013). A diet consisting of eating a lot of foods containing high levels of saturated fats will be at higher risk of being affected by atherosclerosis. The risks are heightened where a diet has high cholesterol levels as well as a high fat intake diet. Avoiding foods high in cholesterol will reduce the risk of atherosclerosis; this could be a challenge however as cholesterol is found in all animal products. Another factor that puts people at risk of atherosclerosis is being overweight or obese, eating a healthy balanced diet along with exercising on a regular basis will reduce the risk and this alongside taking medications such as ACE inhibitors are ways in which this condition is treated (NHS, 2014). People who have a diagnosis of either type 1 or type 2 diabetes become more at risk of this condition also (NHS, 2014).
  3. Rickets more commonly affect children; this is a condition that causes the bones to become soft and weak which can lead to having bone deformities. The most common cause of rickets is the lack of vitamin D and calcium. Vitamin D is mostly provided by the exposure of sunlight to the skin, however it is also found in some foods such as oily fish. Including vitamin D and calcium enriched foods will help to prevent rickets. In some people it is advised that a vitamin D supplement be taken to reduce the risk of being affected by rickets (NHS, 2013).


  1. Digestion is an important process for the absorption and assimilation of nutrients from food. This is due to the larger molecules needing to be broken down into smaller molecules. For example when eating carbohydrates the digestive process is to chew the food to make it smaller and then the enzymes then break down the starch into sugars; whereas protein is broken down by protease enzymes and stomach acid which also helps to kill any harmful micro-organisms present in the food. After digestion the small molecules of food are absorbed by the small intestine and are carried around the body in the blood stream to which ever area they are needed (BBC Bitesize, 2014). Assimilation is the process to which chemicals from the food are taken to the cells of the body and stored (ivy-rose, 2014).

Organ/body part



Mouth/Buccal cavity

Food is chewed

To enabled the food break down from larger to smaller molecules.


Pushes food down into the stomach

To enable food to reach the stomach, the oesophagus contracts pushing food through the sphincter and into the stomach.


Stores and digests

The stomach mixes and stores the food until it can be further digested.

Small intestine

Digestion and absorption of nutrients

The duodenum mixes any undigested food with bile from the liver to complete the process of digestion. The jejunum (middle part) is the primary site of absorption of nutrients. Finally the ileum extracts any missed nutrients before passing food to the large intestine.

Large intestine

To remove water from digested material before it returns to the blood stream.

The large intestine receives any leftover material from the chemical digestion, this is nutrient free. Its main purpose is to extract any water from the undigested material; this is removed by the villi before returning it to the blood stream.


Opening of the end of the digestive system

This is to allow of any waste materials to exit the body, this is the end of the digestive process.


Name of digestive juice

Site of production

Enzymes in digestive juice

Functions of the enzymes


Saliva is produced by several glands within the mouth

Salivary amylase (ptyalin)

This helps break down of starchy foods; it also aids the process of chewing and swallowing.

Gastric juice

Gastric juices are produced by oxyntic cells in the stomach.

Protease (pepsin)


Pepsin helps to digest protein foods eaten.

Renin’s function is to curdle milk in the stomach to ensure it is proteins are digested sufficiently.

Intestinal juice

Intestinal juice is produced in the stomach and lining of the intestine.






Entriokinase converts the inactive pancreatic secretion trypsinogen into trypsin, this enzyme is responsible for digesting protein.

Eripsin is responsible for turning peptones into amino acids.

Maltase is an enzyme that catalyses the hydrolysis of disaccharide maltose into simple sugar glucose.

Sucrase breaks down sugar into glucose and molecule of fructose.

Lactase brakes down the a sugar called lactose which is found in dairy products. Lactase breaks down the lactose into smaller particles of glucose and galactose.


  1. Mouth
  2. Liver
  3. Ascending colon
  4. Cecum
  5. Appendix
  6. Anus
  7. Esophagus
  8. Stomach
  9. Pancreas
  10. Large intestine
  11. Small intestine
  12. Ileum

Digestive Organ



The stomachs main function is to break down and digest food to enable the extraction of the necessary nutrients. There are three main functions of the stomach; it is firstly a place of storage of the three meals a day that are eaten. Secondly it helps with the digestive process; it is here that the food is turned into a semi liquid form to allow nutrients to be absorbed. And its third function and extremely important function is that the stomach destructs any contaminants that the food eaten may have contained. This means that very little bacteria and micro-organisms are absorbed into the blood stream with exceptions to aspirin and alcohol.

Small intestine

The small intestine is where 90 per cent of the digestion and absorption of food takes place. This involves the chemical digestion. Its main function is to absorb the nutrients and minerals from foods. After the digestive process of the stomach small amounts of food are passed through to the duodenum part of the small intestine. The pancreas releases digestive juices to this area, this is enriched with enzymes that break down fats, proteins and carbohydrates. This digestive juice also contains sodium bicarbonate which naturalises acid produced by the stomach. In the lining of the small intestine there is a surface of absorption called microvili, this contains minute blood capillary, this is where the nutrients are absorbed and how they enter into the blood.

Large intestine

The large intestine is the final part of the digestive tract. This is where food that is undigested by the small intestine enters, here the water is reabsorbed and destroys any undigested food and fibres. This process causes food waste to harden, forming into faeces before it is excreted through the anus.


The digestive tract contains four layers, the forst being the mucosa, this is the innermost layer which is a lining epithelium, this provides support for the epithelium and will often conatin mucosal glands. Products from food digestion will pass into these capilliries. There will also be lyphodic follicles and plasma cells found here. Aso present will be a thin layer smooth muscles called the muscularis mucosa which aids the movement of the mucosa. Under this there will be submucosa, which is a layer of connective tissue, which will have larger blood vesels, lymphatics and nerves. This can also contain mucous secreting glands , with its main function being to to support the mucosa. There will then be the muscularis propria, which is a smooth layer; there will usually be two layers the inner layer which is the circular and then the outer layer which is the longitudinal. This sections purpose is to send rythmatic waves to enable the foods to move down through the gut. Finally there is the serosa, which is the outer most layer, this is a layer of loose conective tissue which is covered by the visceral pertioneum, this also contains blood vesels lymphatics and nerves. The serosa’s purpose is to cover the organ (Histology Guide, 2014


BBC Bitesize, 2014, [Online] <> [Accessed 22 August 2014]

British Heart Foundation, 2013, Focus on atherosclerosis, [Online] < > [Accessed 22 August 2014]

Bupa,2013, The obesity and type 2 diabetes connection, [Online] <> [Accessed 22 August 2014], 2014, Diabetes Risk Factors, [Online] <> [Accessed 22 August 2014]

Diabetes UK, 2014, Healthy Eating, [Online] <> [Accessed 22 August 2014]

IvyRose Holistic, 2014, Overveiw of the digestive process, [Online] < > [Accessed 22 August 2014]

NHS, 2014, Arthrosclerosis, [Online] < > [Accessed 22 August 2014]

NHS, 2013, Rickets, [Online] <> [Accessed 22 August 2014]

NHS, 2014, Type 2 diabetes – Causes, [Online] <> [Accessed 22 August 2014]

University of Leeds Histology Guide, ND, Four layers of the Gastrointestinal Tract, [Online] <> [Accessed 26 August 2014]