The Digestive System سیستم هضمی

1. The Digestive Systemسیستم هضمی EO 003.01 Part 8

2. Lesson Overviewنقاط تدریسی • مروری بر سیستم هضمی • دهن • بلعوم • مری • معده • پانکراس • کبد و کیسه صفرا • (Insert Dari) • (Insert Dari) • (Insert Dari) • Overview of the digestive system. • Mouth. • Pharynx. • Esophagus. • Stomach. • Pancreas. • Liver and Gallbladder. • Small intestine • Large intestine • Disorders of the GI system

3. The Gastrointestinal Tract (Insert Dari) جوف دهن غده نکفیه دندان زبان بلعوم غده نکفیه مری کبد معده پانکراس کیسه صفرا جیجیونوم اثناعشر کولون نازله الیوم سیکم کولون سیگوئید اپندکس رکتوم مقعد

4. What is digestion? (Insert Dari) Insert Dari • The mechanical and chemical breakdown of food into smaller parts in order to allow for easier absorption into the blood stream.

5. مروری وظایف طرق هضمی Overview of GI tract Functions • دهن---لقمه، جویدن، بلع • بلعوم و مری--- انتقال • معده---- تشوشات میخانیکی; جذب آب والکول • امعای کوچک—جذب و هضم کیمیاوی و میخانیکی • امعای بزرگ---- جذب الکترولیت و ویتامین ها ( K و‌B) • ریکتوم و مقعد --- تغوط • Mouth---bite, chew, swallow • Pharynx and esophagus----transport • Stomach----mechanical disruption; absorption of water & alcohol • Small intestine--chemical & mechanical digestion & absorption • Large intestine----absorption • Rectum and anus---defecation جوف دهن غده نکفیه دندان زبان بلعوم غده نکفیه مری کبد معده پانکراس کیسه صفرا جیجیونوم اثناعشر کولون نازله الیوم سیکم کولون سیگوئید اپندکس رکتوم مقعد

6. Mouth دهن • Lips – fleshy folds that surround the mouth • Teeth – chew, break down food. • Gums – hold the teeth in place. • Tongue – muscular organ located on the floor of the mouth, allows for swallowing to occur as well as the sense of taste (covered in more detail in the sensory organ lecture). • Roof of the mouth – formed by the hard and soft palate. Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

7. Mouth دهن • (Insert Dari) Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

8. Salivary Glands عقدات لعابی Insert Dari • There are 3 salivary glands which produce saliva • Saliva dissolves some of the chewed food and acts as a lubricant, allows for passage through the subsequent portions of the digestive tract.

9. Functions of the Mouth (Insert Dari) Insert Dari • Is the first part of the gastrointestinal tract to receive food. • Mechanical digestion occurs, breaking food into pieces and mixing it with saliva. • The mouth also plays a significant role in voice (oral communication) as well as breathing.

10. Sublingual Absorption of Medications (Insert Dari) • Sublingual (meaning under the tongue) is the process by which medications are absorbed into the blood stream through tissues under the tongue. (Insert Dari)

11. Pharynx and Esophagus (Insert Dari) The pharynx is the passageway leading from the mouth to the esophagus. The esophagus is the passageway leading from the pharynx to the stomach. Both structures are lined with muscle which moves food and liquid to the stomach. (Insert Dari) Insert Dari Insert Dari Insert Dari Insert Dari

12. Esophageal Sphincters(Insert Dari) A sphincter is a circular muscle that maintains constriction around a passageway. The esophagus has both an upper and lower esophageal sphincter. Upper – prevents food from entering the windpipe (trachea). Lower – prevents acid and stomach contents from traveling backwards into the esophagus.

13. Esophageal Sphincters(Insert Dari) Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

14. The Stomach(Insert Dari) Insert Dari • The stomach receives food and liquids from the esophagus and grinds and mixes it with gastric juice so that food particles are smaller and more absorbable. • Gastric juices are highly acidic, mostly due to hydrochloric acid, which is produced by specialized cells in the stomach. • The stomach begins the process of digesting carbohydrates and proteins. • The stomach periodically empties small amount of the mixture into the small intestine for further digestion. Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

15. The Small Intestine(Insert Dari) Insert Dari • The small intestine is one of the most important structures contained within the gastrointestinal tract. • It is here where the majority of digestion (mechanical and chemical) occurs as well as absorption of nutrients into the blood stream. • This is also the major • site for drug absorption • in the body. Insert Dari Insert Dari

16. The Small Intestine(Insert Dari) Insert Dari • There are three sections of the small intestine: • Duodenum • Ileum • Jejunum Insert Dari Insert Dari Insert Dari Insert Dari

17. Structure of the Small Intestine(Insert Dari) • The inner lining of the small intestine has tiny projections called villi. • These projections greatly increase the surface area for absorption of substances. • Insert Dari Insert Dari Insert Dari Insert Dari

18. Villi (Insert Dari) The villi of the small intestine contains blood vessels into which substances are absorbed. The cells that line the villi also have microvilli along their surface which further increases the surface area available for absorption.

19. Villi (Insert Dari) Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

20. Absorption of nutrients and other substances(Insert Dari) Insert Dari • Substances are transported from inside of the intestine to blood vessels in the villi via the following mechanisms: • Paracellular – transport between the cells lining the intestine (A) • Transcellular – through the cell • Passive – does not require energy (B) • Active – requires energy (C) • Certain cells are able to • intake substances by • engulfing the molecule, • which is called • Endocytosis (D). • See next slide for • description Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

21. Endocytosis (Insert Dari) Note: Endocytosis requires energy to occur (Insert Dari)

22. The Large Intestine, Rectum and Anus (Insert Dari) • The main function of the large intestine is to absorb liquids and maintain the balance of electrolytes (salts) in the body. • The left over matter that is indigestible constitutes the feces. • The large intestine stores fecal material until it can be evacuated by defecation through the rectum and anus. • The rectum is also a site of drug absorption in the body. Insert Dari Insert Dari Insert Dari

23. Additional Organs of the Gastrointestinal Tract (Insert Dari) • Liver • Gallbladder • Spleen • Pancreas (Insert Dari) جوف دهن غده نکفیه دندان زبان بلعوم غده نکفیه مری کبد معده پانکراس کیسه صفرا جیجیونوم اثناعشر کولون نازله الیوم سیکم کولون سیگوئید اپندکس رکتوم مقعد

24. The Liver (Insert Dari) • The main functions of the liver are: • (1) Metabolism of various substances. • (2) Synthesis of cholesterol • (3) Production of bile (bile aids in the digestion of fats). • (4) Transportation of certain nutrients and drugs • (5) Store nutrients • Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari Insert Dari

25. The Portal Vein System (Insert Dari) Spleen (Insert Dari) Substances that have been absorbed from the small intestine are delivered to the liver via the portal vein system. (Insert Dari) Liver (Insert Dari) Gallbladder (Insert Dari) Pancreas (Insert Dari)

26. Metabolism of Drugs by the Liver(Insert Dari) Insert Dari • Drug metabolism is defined as the body modifying the chemical structure of a medication to assist in elimination from the body. • The resulting chemical structure is called a metabolite. • Although metabolism typically inactivates drugs, some drug metabolites are active—sometimes even more so than the original compound.

27. Functions of the Gallbladder, Pancreas and Spleen(Insert Dari) • Gallbladder – stores bile prior to it being released into the small intestine. • Pancreas – produces enzymes and hormones that are important during the digestive process. • Spleen – acts as a blood filter. • (Insert Dari)

28. Disorders of the Gastrointestinal System (Insert Dari)

29. Gastroesophageal Reflex Disease ریفلکس مری-معدی • در صورت ایکه معصره سفلی مری باز نگردد. • اسید معده وارد مری گردیده و سبب بوجود آمدن سوزش مری(GERD) میگردد. • If lower esophageal sphincter fails to close • stomach acids enter esophagus & cause heartburn (GERD) Insert Dari Insert Dari

30. Vomiting (Emesis) (Insert Dari) • Forceful expulsion of the contents of ones stomach through the mouth. • Can have many causes: • contaminated food • motion sickness • pregnancy • side effect of medication Insert Dari

31. Diarrhea (Insert Dari) Insert Dari • Bowel movements (stools) that are loose and watery. • Can be caused by a bacterial, viral or parasitic infection. • It is very common and usually not serious, however it can require treatment.

32. Constipation (Insert Dari) Insert Dari • Infrequent bowel movements or bowel movements that are difficult to pass. • Can have many different causes: • - diet (lack of fibre) • - side effect of a medication • - structural abnormality • - disease of the bowel

33. Appendicitisالتهاب اپندکس (اپندیسیت) • عبارت از التهاب اپندکس بوده که از سبب مسدود شدن لومن بوسیله موادغذایی، اجسام اجنبی، کارسینوما، تضیق یا معوج شدن آن بوجود میاید • اعراض • تب بلند، افزایش کریوات سفید خون، تعداد نوتروفیل بیشتر از %75 میرسد • درد های راجعه، بی اشتهایی، دلبدی و استفراغ • انتانات ممکن به گانگرین پیشرفت نماید و سبب تثقب معایی در 24 الی 36 ساعت گردد • Inflammation of the appendix. • Symptoms • high fever • pain, anorexia, nausea and vomiting • Infection may progress to gangrene and perforation within 24 to 36 hours

34. In-class Assignment(Insert Dari)

35. 1. Put the following organs in the order that food enters the digestive system: (Insert Dari) • Small intestine • Esophagus • Mouth • Pharynx • Large Intestine • Rectum • Stomach Insert Dari

36. 1. Answer: Put the following organs in the order that food enters the digestive system: (Insert Dari) • C) Mouth • D) Pharynx • B) Esophagus • G) Stomach • A) Small Intestine • E) Large Intestine • F) Rectum Insert Dari

37. 2. Match the following structures with their function: (Insert Dari) Insert Dari A) Rectum/Anus B) Stomach C) Pharynx/Larynx D) Mouth E) Small Intestine F) Large Intestine • bite, chew, swallow • Transport • Mechanical digestion • Chemical and mechanical digestion, as well as absorption • Absorption • Defecation

38. 2. Match the following structures with their function: (Insert Dari) Insert Dari Rectum/Anus – Defecation B) Stomach - Mechanical digestion C) Pharynx/Larynx – Transport D) Mouth - bite, chew, swallow E) Small Intestine - Chemical and mechanical digestion, as well as absorption F) Large Intestine - Absorption

39. 3. Where are the majority of medications absorbed?(Insert Dari) • Stomach • Small Intestine • Large Intestine • Mouth • Insert Dari

40. 3. Where are the majority of medications absorbed?(Insert Dari) • Stomach • Small Intestine • Large Intestine • Mouth • Insert Dari

41. 4. Identify which mechanisms of absorption require energy and which do not: (Insert Dari) • Paracellular • Diffusion • Carrier mediated • Endocytosis • (Insert Dari)

42. 4. Answer: Identify which mechanisms of absorption require energy and which do not: (Insert Dari) • Paracellular – no energy • Diffusion – no energy • Carrier mediated – energy required • Endocytosis – energy required • (Insert Dari)

43. 5. What statement best describes gastroesophageal reflux?(Insert Dari) • Insert Dari • Burning sensation in the chest • The lower esophageal sphincter is not closing properly • The irritation is caused by gastric acid entering the esophagus • All of the above.

44. 5. Answer: What statement best describes gastroesophageal reflux?(Insert Dari) • Insert Dari • Burning sensation in the chest • The lower esophageal sphincter is not closing properly • The irritation is caused by gastric acid entering the esophagus • All of the above.