• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The structure and function of the ileum in relation to absorption and digestion.

Extracts from this document...

Introduction

SUMUDU LANKATILAKE 17-FEB-03 THE STRUCTURE AND FUNCTION OF THE ILEUM IN RELATION TO ABSORPTION AND DIGESTION The ileum is the second part of the small intestine located after the duodenum. It has a vital function in digestion and has a suitable structure to accommodate for its functions. The ileum is 6 meters long and the main site foe the absorption of the soluble products of digestion. The ileum is efficient at this for the following reasons: * It is fairly long and presents a large absorbing suface to the digested food. * Its internal surface is greatly increased by circular folds bearing thousands of projections called villi. These villi are about 0.56mm long and may be finger like or flattened in shape. * The lining epithelium is very thin and the fluids can pass rapidly through it. ...read more.

Middle

The hepatic potal vein and the umphatic system run through the sub mucosa. The sub mucosa and mucosa is separated by a layer called muscularis mucosae. The following two layers are the muscle layers and beneath all the layers is the serosa. The main function of the small intestine is absorption although some digestion does occur. The final stages of digestion of carbohydrates, lipids and proteins occur here, while absorption occurs. Carbohydrates in the form of monosaccharides and amino acids are absorbed partly by diffusion and partly my active transport. Soon after a meal there will be a higher concentration of monosaccharides and amino acids in the ileum, and so a concentration gradient will exist and diffusion of these molecules will occur across the mucosal epithelium in the blood capillaries. ...read more.

Conclusion

For digestion that occurs in the ileum intestinal juice is secreted by the small intestine and the digestion occurs in the small intestine itself. The intestinal juice contains maltase, sucrase, lactase, enterokinase, aminopeptidase, lipase, nucleotidase, mucus. Each are an enzyme which have a specific molecule to act on. Maltase acts on maltose and converts it into glucose. Sucrase acts on sucrose and breaks it down into glucose and fructose. Lactase acts on lactose and breaks it down into glucose and galactose. Enterokinase acts on trypsinogen and breaks it down to trypsin. Aminopeptidase acts on peptides and converts it into amino acids. Lipase acts on fats and converts it into fatty acids and monoglycerides. Nucleotidase breaks down nucleotides and mucus is also secretd for the lubrication of the food mass. The product molecules are all easier to absorb than their precursor molecules. The ileum of the small intestine eventually leads into the large intestine for further absorption. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

4 star(s)

Much of the relevant information is included in this essay but its overall structure needs some reworking. A clear distinction between digestion and absorption would make it easier to follow. An alternative approach is to deal with each of the four layers of the ileum wall in turn, relating their structure and function.
Finally, the different cell types of the intestinal epithelium together with their functions was not covered in enough detail. Paneth cells, goblet cells, absorptive cells (enterocytes) deserve mention at A' Level.
This is a good example of an essay which needs careful planning before putting pen to paper (or fingers to keyboard.)

Marked by teacher Ross Robertson 01/03/2013

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    Cellular Structure and Function

    5 star(s)

    epithelium lines most of the digestive tract where it absorbs nutrients, and secretes enzymes and mucus. The main role of simple columnar epithelium is to provide an inner barrier for organs such as the stomach and intestines, protecting them from naturally present bacteria and acids that could harmful if ingested.

  2. Marked by a teacher

    Investigating the effect of enzyme concentration on the activity of cellulase.

    5 star(s)

    Care should be taken when heating the water bath. It is recommended that the enzyme cellulase be stored at a temperature 25?C or below to maintain it declared activity for at least 3 months. Keeping it at lower temperatures (5-10?C)

  1. Marked by a teacher

    effect of concentration of copper sulphate on the action of amylase to break down ...

    4 star(s)

    Main method 1. Using different pipettes measure out 4ml of amylase, 4ml of starch, 2ml of buffer solution and 1ml of 0.1% of copper sulphate solution. 2. Add the starch, buffer solution and copper sulphate solution into a test tube.

  2. Marked by a teacher

    The structure and function of Proteins

    and giving off a molecule of water. The end result is Glycanine, a dipeptide or Protein. Hence proteins are referred to as "polypeptides" due to the fact that they are many amino acids joined together by peptide bonds. The structures of proteins themselves are put into several levels: primary, secondary, tertiary and quaternary.

  1. Qualitative tests for carbohydrates

    Finally, that the Bial's test for pentose gives a blue result when reacted with the Xylose solution but not the others.

  2. An Investigation Into The Digestion Of Milk By Trypsin.

    At this pH, the enzyme amylase, from your saliva cannot work at all. Inside most cells the enzymes work best at a pH of 7, as it is neutral. The pH or temperature at which this enzyme works is called its optimum pH or temperature.

  1. An experiment to find of the isotonic point of root vegetables cells in contents ...

    Parsnip 2. Swede 3. Carrot 4. Potato. From these results I will change my range for my concentrations used as my results show that a concentration below 0.4 is required as three of my root vegetables showed a mass decrease at the 0.4 molar sucrose solution.

  2. An experiment to investigate the effect of enzyme concentration on the rate of milk ...

    Phenolphthalein changes from pink to colourless when the solution goes below about pH9. This colour change is a lot easier for the human eye to detect when the beaker is held in front of a white tile. Other indicators such as methyl orange are more difficult to detect the end point due to the less distinct colour change in.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work