1. Unit 6 The Digestive System

2. Word Formation rect/o- 直肠 ( rectum ) an/o- 肛门 ( anus ) saliv/o- 唾液 ( saliva ) de- 脱离, 分离 ( decompose, decontamination ) dis- 分开, 分离 (disassemble ) peptid/o- 肽 ( peptide, polypeptide) muc/o- 黏液 ( mucosa) -gen 原, 发生物 ( pepsinogen, glycogen )

3. hydr/o- 水 ( hydrolyze, hydrolysis ) gastr/o- 胃 ( gastrin ) -in … 素, … 剂 ( gastrin ) duoden/o- 十二, 十二指肠 ( duodenum ) jejun/o- 空, 空肠 ile/o- 回肠 ( jejunum ) ( ileum ) fec/o- 粪便 ( defecation, feces ) carbo- 碳 ( carbohydrate )

4. -ate … 酸盐 ( carbonate, bicarbonate ) tox/o- 毒，毒素 ( detoxification ) syn- 连, 合, 联, 共 ( syndrome, synthesize ） ex(o)- 外， 在外 ( excretion )

5. Group Discussion 1. Can you name the organs of digestive system in English ? English ? 2. Talk about common disorders in digestive system.

6. Clinical and pathological conditions appendicitis----inflammation of the appendix cholecystitis---- inflammation of the gallbladder colitis----inflammation of the colon enteritis----inflammation of the small intestine gastroenteritis----an infection that causes vomiting and diarrhea. gastritis----inflammation of the stomach hepatitis----inflammation of the liver

7. pancreatitis----inflammation of the pancreas parotitis----inflammation of the parotid glands heartburn----when the contents of the stomach back up the esophagus. ulcer---- a hole in the mucous membrane lining the stomach or duodenum.

8. Introduction to Introduction to Digestive system We need food to fuel our bodies for energy, growth and repair. The digestive system converts the foods we eat into their simplest forms, like glucose (sugars), amino acids (that make up protein) or fatty acids (that make up fats). The broken down food is then absorbed into the bloodstream from the small intestine and the nutrients carried to each cell in the body.

9. The digestive tract begins at the mouth and ends at the anus. It can be thought of as a long, muscular tube, over 10 metres long, with digestive organs attached along the way.

10. The mouth and esophagus Digestion begins in the mouth. The food is ground up by the teeth and moistened with saliva to make it easy to swallow. Saliva also has a special chemical, called an enzyme, which starts breaking down carbohydrates into sugars. Once swallowed, muscular contractions of the esophagus massage the ball of food down into the stomach.

11. The stomach The food passes through a sphincter or small muscle ring into the stomach, where it is mixed with gastric juices. The stomach is a muscular bag and it churns the food to help break it down mechanically. The food is then squeezed through a second sphincter into the first part of the small intestine, called the duodenum.

12. The small intestine Once in the duodenum (small intestine), the food is mixed with more digestive enzymes from the pancreas and bile from the liver. Pancreas The pancreas is one of the largest glands in the human body. As well as digestive juices, it secretes a hormone called insulin. Insulin helps to regulate the amount of sugar in the blood. Diabetes is a condition caused by problems with insulin production.

13. Liver The liver has a number of different roles in the body, including:  Breaking down fats, using bile stored in the gallbladder  Processing proteins and carbohydrates  Filtering impurities and toxins.

14. Absorption happens in the small intestine The food is squeezed into the lower parts of the small intestine, called the jejunum and the ileum. Nutrients are absorbed from the ileum, which is lined with millions of finger-like projections called villi( 绒毛 ). Each villus is connected to a mesh of capillaries.This is how nutrients pass into the bloodstream.

15. The large intestine Once all the nutrients have been absorbed, the waste is moved into the large intestine, or bowel. Water is removed and the waste (feces) is stored in the rectum. It can then be passed out of the body through the anus.

16. Things to remember Food is broken down by the digestive system to give energy to every cell in the body. The digestive tract starts at the mouth and ends at the anus.

17. 齿龈 悬雍垂 乳头状突起 前磨牙 犬牙 / 尖牙 切牙 / 门牙 磨牙 腭扁桃体

18. Palate The palate is the roof of the oral cavity. It separates the oral cavity from the nasal cavity. The anterior portion, the hard palate, is supported by bone. The posterior portion, the soft palate, is skeletal muscle and connective tissue. Posteriorly, the soft palate ends in a projection called the uvula. During swallowing, the soft palate and uvula move upward to direct food away from the nasal cavity and into the oropharynx.

23. The pancreas is an elongated gland that is below the stomach. It produces pancreatic juice that contains digestive enzymes. The pancreas also secrets insulin into the blood. Insulin is needed to allow glucose or sugar from food to get into the bloodstream. People who cannot produce insulin are diabetics.

24. The largest gland in the body is the liver. It is on the right side of the body underneath the ribs. It weighs about three pounds and is eight inches long. The liver stores a form of glucose called glycogen.

25. Vitamin A is manufactured in the liver. Bile which is needed to breakdown fat, is made in the liver.This organ is also where alcohol, drugs, bacteria and old blood cells are broken down and removed from the body. Damage to the liver can be serious because this organ is extremely necessary to life.

26. The gallbladder is a small sac on the underside of the right lobe of the liver. It stores bile that is made by the liver. Bile travels from the liver through the hepatic ducts to the gallbladder. It holds about two ounces of bile. Bile is needed to breakdown the fat that is in food.

27. Understanding the Text Para.1Question: 1.What are the organs that do not exactly belong to the digestive system ? digestive system ?Para.2Question: 2.What is the function of mastication ? Para.3Question: 3.What is the function of saliva ?

28. Salivary gland A gland that secretes saliva, especially any of three pairs of large glands, the parotid(1), submandibular(2), and sublingual(3), whose secretions enter the mouth and mingle in saliva.

29. Function Saliva keeps the mouth and other parts of the digestive system moist. Saliva keeps the mouth and other parts of the digestive system moist. Saliva also helps break down carbohydrates (with salivary amylase, formerly known as ptyalin) and lubricates the passage of food down from the oropharynx to the stomach. Saliva also helps break down carbohydrates (with salivary amylase, formerly known as ptyalin) and lubricates the passage of food down from the oropharynx to the stomach. Saliva also has elements that help to neutralise the acid responsible for tooth decay; this is called a buffer. Saliva also has elements that help to neutralise the acid responsible for tooth decay; this is called a buffer. The antibacterial properties within saliva help to sustain a neutral balance and prevent the development of germs. The antibacterial properties within saliva help to sustain a neutral balance and prevent the development of germs.

30. Para.4Questions: 4.What is the function of esophagus ? 5.What is GERD? Gastroesophageal reflux disease (GERD 胃食管反流病 ) is a gastric disorder which causes stomach acids to back up into the esophagus, the tube leading from the mouth to the stomach. This action causes pain, which is often called heartburn. GERD can disrupt sleep and make eating difficult. It can lead to respiratory infections, ulcers, and even cancer.

31. Para.5Questions: 6.What are the components of the stomach ?Can you say something about its functions ? Para.6-7Question: 7.What are the functions of the fundus ?

32. hydrochloric acid--- 盐酸 untwist--- vt. to loose 解开 ( 缠绕的东西 ), 朝反方向扭开 e.g. 1) untwist a knot 解开一个结 e.g. 1) untwist a knot 解开一个结 2) untwisting the complex three-dimensional 2) untwisting the complex three-dimensional protein chains protein chains 分解复杂的具有三维结构的蛋白链 (p91) 分解复杂的具有三维结构的蛋白链 (p91) Difficult Points

33. denaturation of proteins ----the changes in the physical and physiological properties of a protein that are brought about by heat, X-rays, or chemicals. These changes include loss of activity (in the case of enzymes) and loss (or alteration) of antigenicity (in the case of antigens) 变性作用 由热、 X 线或化学物质引起的蛋白物理和生理 特点的变化。这些变化包括活性 ( 酶 ) 和抗原性 ( 抗原 ) 的丧 失。

34. pepsinogen: ----the inactive precursor ( 先质, 前体 ) to pepsin, formed in the cells of the mucous membrane of the stomach and converted to pepsin by hydrochloric acid during digestion 胃蛋白酶原 ; 胃蛋白酶的一 种不活跃原，在胃粘膜细胞 中形成并在消化的过程中通过盐酸转化为胃蛋白酶 pepsin: ----a digestive enzyme found in gastric juice that catalyzes the breakdown of protein to peptides 胃蛋白酶 ; 胃液中一种消化酶, 加速将蛋白质分解成肽

35. Para.8Question: 8.What is the function of antrum ? In biology, “antrum”( is a general term for a cavity or chamber which may have specific meaning in reference to certain organs or sites in the body. Examples include:

36. antrum cardiacum---- 贲门窦 mastoid antrum---- 乳突窦 / 鼓窦 / 鼓房 pyloric antrum---- 幽门窦 gastric antrum---- 胃窦 dental antrum---- 牙窦；髓腔 autrum auris---- 耳道

37. 1) The antrum was involved. ( 胃 ) 窦部受累。 2) The stomach can be divided into fundus, body, and antrum. 胃可分为底部, 体部和窦部。 3) The Nursing Experience of 93 Cases of Nose Antrum Endoscopy 鼻内窥镜鼻窦手术 93 例 护理体会 More examples:

41. Para.9Question: 9.What are the characteristics of the small intestines? Para.10-12Question: 10.What sections make up the small intestines ? Do they have any different characteristics ? Do they have any different characteristics ?

42. Para.13Question: 11.What does this paragraph mainly talk about ? Limitation of digestion process of the small intestine deplete/depletioningest/ingestionresist/resistant/resistance Difficult Points

43. 1. 可观察到海洋纤毛虫吞食单细胞生物以获得它们 的叶绿体。 的叶绿体。 Marine ciliates can be observed ingesting other single-celled creatures and harvesting their chloroplasts. The bacteria are resistant to (have developed a resistance to ) some antibiotics. 2. 这种细菌对某些抗生素耐药。 Venous blood is depleted of oxygen by the tissues and returns to the lungs for oxygenation. 3. 被组织脱氧的静脉血回到肺进行氧和。

44. Para.14-15Question: 12.What is the general function of large intestine ? Is there anything special about it ? Is there anything special about it ?Para.16Questions: 13.What does this paragraph mainly talk about ? 14.What components are there in pancreatic juice ? Para.17-18Question: 15.What are the functions of liver ?

45. Cholesterol A white crystalline substance, found in animal tissues and various foods, that is normally synthesized by the liver and is important as a constituent of cell membranes and a precursor( 前体 ) to steroid( 类固醇 ) hormones. Its level in the bloodstream can influence the pathogenesis of certain conditions, such as the development of atherosclerotic plaque( 动脉粥样硬化斑块 ) and coronary artery disease( 冠心病 ). Difficult Points

46. A good diet can decrease blood cholesterol levels. A good diet can decrease blood cholesterol levels. Soluble fibre, polyunsaturated fat( 多不饱和脂肪 ) Soluble fibre, polyunsaturated fat( 多不饱和脂肪 ) (especially fish fats which contain omega-3 fatty acids), (especially fish fats which contain omega-3 fatty acids), and monounsaturated fat( 单不饱和脂肪 )(such as olive and monounsaturated fat( 单不饱和脂肪 )(such as olive oil) may all lower cholesterol levels. Regular aerobic oil) may all lower cholesterol levels. Regular aerobic exercise helps to reduce deposition of cholesterol in exercise helps to reduce deposition of cholesterol in blood vessels. blood vessels.

47. Para.19Question: 16.What is the general function of gallbladder ? Difficult Points Difficult Points bile acids----the organic acids in bile; mostly occurring as bile salts. as bile salts. 胆汁酸 胆汁中的有机酸, 大多以胆盐存在。

48. Phrases in the Text 1. taste receptors 2. salivary glands 3. digestive tract 4. hydrochloric acid 5. gastric fundus mucosa 6. amino acids 7. pancreatic juice 8. gastrointestinal system