Human Digestive System

1. Human Digestive System AminaBouhitem

2. The structure of the digestive system

3. Major food contents • Carbohydrates: • The digestion of Carbohydrates occurs by chemical reactions which break the big molecules into Glucose. • using three different enzymes, Salivary amylase, Pancreatic amylase and Maltase.

4. Protein: are polymer chains of amino acids. • Are broken down to provide amino acids, using three enzymes, Pepsin, Trypsin and peptidases.

5. Lipids: the body uses the fat as a fuel • Have several forms.ie Saturated, unsaturated • Broken down to Fatty Acids and Glycerol by using Lipase enzyme.

6. Nucleic acid: biological molecule which is essential for life • Broken down by Nuclease and Nucleosides enzymes to provide nucleotides.

7. http://www.youtube.com/watch?v=tTZUBOhm6xw&feature=related • http://www.youtube.com/watch?v=M4e6qf8r8Tk&feature=related

8. The function of organs in food digestion • Mouth: • Chews the food and breaks it to small pieces • Early digestion • Salivary Glands- Salivary Amylase

9. Esophagus • Located in throat near Trachea • Receives food from mouth, • Swallows it by muscular contraction. • Delivers the food to stomach

10. Stomach • Big muscular organ which churns up the food and contains it while mixing with several enzymes. • Protects it’s wall against acid by lining with mucous. • Protein is broken in stomach

11. Pancreas • Secretes digestive enzymes into duodenum • These enzymes include Pancreatic Amylase, Trypsin, Nuclease, Nucleosidases and Lypase. • In order to digest all the four major food contents

12. Liver • Processes the nutrients absorbed by small intestine. • Secretes ‘Bile’ which helps digesting fat. • Makes various Chemicals needed for the body from the absorbed nutrients.

13. Small Intestine • Is 22-foot long muscular tube that breaks down food using enzymes released by pancreas, bile and liver • Peristalsis responsible for the movement of food • Absorption of nutrients takes place in the small intestine

14. Absorption: • The soluble products are first taken up by various mechanisms into the epithelial cells that line the gut. • These epithelial cells then load the various absorbed molecules into the blood stream.

15. Assimilation: • The soluble products of digestion are then transported to the various tissues by the circulatory system. • The cells of the tissues then absorb the molecules for use within this tissues

16. The structure of the villus • Blood supply in the villus which absorb the end products of digestion from the epithelial cells • The lacteals (green) that receive the lipoproteins before transporting them to the circulatory system. • Muscular walls that maintain the movement of chyme by peristalsis.

17. Blood

18. Large Intestine • Is 6 foot long tube connects the small intestine to the rectum • is specialized organ for processing waste by absorbing water. • Changes contents from liquid to semi-solid state.

19. Rectum and Anus • Rectum is an 8-inch chamber. It receives feces from large intestine and holds it until excreted by Anus which is 2- inch long organ consisting of pelvic floor muscles. Anus is the last part if digestive tract.

20. Keep your digestive system in good shape by eating balanced meals with a lot of fruits and vegetables

21. Questions?

22. References: • http://click4biology.info/c4b/6/hum6.1.htm#four • http://www.cchs.net/health/health-info/docs/1600/1699.asp?index=7041 • http://www.yteach.co.uk/page.php/resources/view_all?id=amino_acid_aminopeptidases_bile_salts_carbohydrate_digestion_carboxyl_group_(COOH)_of_amino_acid_carboxypeptidase_casein_caseinogen_chymosin_chymotrypsin_dipeptide_disaccharidases_page_4