Digestive system by Shriya Sangral -@sangralshriya
- 1. ANATOMY OF HUMAN DIGESTIVE SYSTEM SUBMITTED BY: Shriya Sangral M.Sc. Human Genetics Institution of Human Genetics, University of Jammu
- 2. LEARNING OBJECTIVE • To impart the anatomy of human digestive system. • To demonstrate the functions of various enzymes involved in the digestion process • To highlight the different functions and the mechanism of the digestive system. Digestive System By: Shriya Sangral 2
- 3. CONTENT Introduction Alimentary Canal Accessory organs References Digestive System By: Shriya Sangral 3
- 4. DIGESTIVE SYSTEM It Consist of two part: • Alimentary Canal: Consist of 4 layers Serosa Muscularies Sub mucosal Mucosa • Accessory organs Digestive System By: Shriya Sangral 4
- 5. ALIMENTARY CANAL Alimentary Canal: • Also known as gastrointestinal tract (GI Tract) • 5-7 meter long • Muscular walls • It consist of: mouth, buccal cavity, pharynx, oesophagus, stomach, small intestine, large intestine, anus Digestive System By: Shriya Sangral 5
- 6. ACCESSORY ORGANS Accessory organs: • Salivary gland • Gastric gland • Pancreas • Liver • Gallbladder Digestive System By: Shriya Sangral 6
- 7. MOUTH Structure: • Transverse slit • Bounded by two soft movable lips • Lead to buccal cavity Function: • Ingestion of food into the buccal cavity Digestive System By: Shriya Sangral 7
- 8. BUCCAL CAVITY Also known as oral cavity and contain salivary gland. Structure: Consist of no. of teeth and a muscular tongue Teeth: Fixed in socket of jawbones, such teeth are thecodont There are two sets of teeth during lifespan i.e. diphyodont Deciduous (temporary milk) Permanent teeth 32 permanent teeth in an adult human Incisors (I) Premolar (PM) Canine (C) Molar (M) Made up of Enamel (mineralized tissue, hard, shinny layer of calcified tissue) Digestive System By: Shriya Sangral 8
- 9. BUCCAL CAVITY Tongue: Freely movable, muscular organ Attached to the floor of oral cavity by Frenulum Papillae (contain taste buds) present on its upper surface Salivary gland: Produce saliva Saliva contain: Mucus Enzymes (salivary amylase & lysozyme) Electrolytes Digestive System By: Shriya Sangral 9
- 10. BUCCAL CAVITY Reaction: Starch Maltose Function: Mastication of food Lubrication of food Facilitation of swallowing Starch hydrolysis (30%) Digestive System By: Shriya Sangral Salivary amylase pH 6.8 10
- 11. PHARYNX AND OESOPHAGUS Structure: Pharynx: 12cm long tube Oesophagus: 25cm long tube Function: Help in the passage of food. Digestive System By: Shriya Sangral 11
- 12. STOMACH Structure: • 30cm long and 15cm wide • 4 regions: Cardiac region (broad) Fundus (often contain air/gas) Body Pyloric region (narrow) Digestive System By: Shriya Sangral 12
- 13. STOMACH Gastric gland: • Present in the mucosa layer • Produce gastric juice • Contain 3 type of cells Mucus neckcell: secrete mucus Peptic cell: secrete proenzyme (pepsinogen) Parietal cell: secrete HCl and intrinsic factor • Small amount of lipases also secreted Digestive System By: Shriya Sangral 13
- 14. STOMACH Reaction: Pepsinogen Pepsin Protein Peptide Function: Store food for 4-5 hours Absorption of water, simple sugar, alcohol Production of HCl, enzymes, mucus, bicarbonate ions Protein hydrolysis Lubrication Digestive System By: Shriya Sangral HCl pH 1.8 (inactive) (active) Pepsin 14
- 15. SMALL INTESTINE Structure: • 6m long and narrow tube • Longest part of alimentary canal • Comprises of 3 parts Duodenum: 25-38cm long Jejunum: 2.5m long Ileum:2-4m long Digestive System By: Shriya Sangral 15
- 16. SMALL INTESTINE Bile and Pancreatic juice release into the stomach through hepatic-pancreatic duct. • Bile Juice: Contain cholesterol, bile salts Contain bile pigments and phospholipids Help in emulsification of fats. Don’t contain any enzyme Digestive System By: Shriya Sangral 16
- 17. SMALL INTESTINE • Pancreatic juice: It contain various enzymes (inactive) Trypsinogen Amylase Lipases Nucleases Chymotrypsinogen Procarboxypeptidases • Intestinal juice: Contain various enzymes Disaccharides Dipeptidases Lipases Nucleosidases Digestive System By: Shriya Sangral 17
- 18. SMALL INTESTINE Reactions: • Breakdown of Proteins: Trypsinogen Trypsin Chymotrypsinogen Chymotrypsin Procarboxypeptidases carboxypeptidases Protein Dipeptides Amino acids Protein Dipeptides + Amino acids Digestive System By: Shriya Sangral enterokinases Trypsin dipeptidases trypsin trypsin 18 chymotrypsin/ carboxypeptidases
- 19. SMALL INTESTINE • Breakdown of Starch: Starch Maltose 2(Glucose) • Breakdown of fats: Fats Triglycerides Diglycerides Monoglycerides • Breakdown of nucleic acid: Nucleic acid Nucleotides Nucleosides Nucleosides Sugar + Bases Digestive System By: Shriya Sangral amylases lipases maltase lipases lipases nucleases nucleotidases nucleosidases 19
- 20. SMALL INTESTINE Function: • Muscularies layer show various movement. • Mixing of food • Facilitates digestion • Secretion of intestinal juice • Bile and pancreatic juices released into it through Hepatic-pancreatic duct Digestive System By: Shriya Sangral 20
- 21. LARGE INTESTINE Structure: • 1.5m long • Wider than small intestine • It has 3 regions: Caecum Colon Rectum Digestive System By: Shriya Sangral 21
- 22. LARGE INTESTINE Function: • Mucus secretion • Absorption of water • Absorption of minerals • Absorption of certain drugs • Temporary storage of undigested food Anus: Removal of unabsorbed/waste product through anus. Digestive System By: Shriya Sangral 22
- 23. PANCREAS • Compound elongated organ • Exocrine portion secretes alkaline pancreatic juice and enzymes • Endocrine portion secretes hormones, insulin, glycogen • Secrete Mucus and bicarbonate that protect intestinal mucosa from acid and provide pH 7.8 Digestive System By: Shriya Sangral 23
- 24. LIVER AND GALLBLADDER Liver: • Largest gland • About 1.6kg in weight • Secretes bile juice by hepatic cells Gallbladder: • Thin muscular sac • Store bile juice Digestive System By: Shriya Sangral 24
- 25. REFERENCES • Principles of anatomy and physiology, 12th edition by Gerard J. Tortora and Bryan Derrickson • Text book of biology by P.S. Dhami, Dr. G. Chopra, Dr. H.N. Srivastava • Human physiology by Dr. Neela Bakore • Cdn.Britannica.com Digestive System By: Shriya Sangral 25
- 26. THANK YOU Digestive System By: Shriya Sangral 26