1. 消化系統
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2. Overview of the Digestive Tract
The Digestive System
Consists of the muscular digestive tract消化管 assisted by various accessory organs附屬器官
Digestive functions include:
Ingestion
Mechanical processing
Digestion
Secretion
Absorption
Excretion
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

3. Overview of the Digestive Tract
Digestive Tract Components
Oral cavity
Pharynx
Esophagus食道
Stomach胃
Small intestine小腸
Large intestine大腸
Rectum直腸
Anus肛門
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

4. Overview of the Digestive Tract
The Components of the Digestive System and Their Functions
Figure 16-1

5. Overview of the Digestive Tract
The Structure of the Digestive Tract 皺襞
腸繫膜 漿膜
黏膜下層
黏膜層
Figure 16-2(a)

6. Overview of the Digestive Tract
The Structure of the Digestive Tract 絨毛
Figure 16-2(b)

7. Overview of the Digestive Tract
Movement of Digestive Materials
Involuntary control of smooth muscle of muscularis externa
Two kinds of movement
Peristalsis蠕動 propels material along the tract
Segmentation churns material in the small intestine
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

8. Figure 16-3 1 of 4 Contraction of circular muscles behind food mass
Longitudinal
muscle
Circular
muscle
From
mouth To
anus
Contraction of longitudinal
muscles ahead of food mass
Contraction
Contraction
Contraction of circular muscle
layer forces food mass forward
Figure 16-3
1 of 4
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

9. The Oral Cavity Functions of the Oral Cavity
Sensory analysis of potential foods
Mechanical processing using teeth, tongue, and palate
Lubrication of food by mucus in saliva
Enzymatic digestion by enzymes in saliva
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

10. The Oral Cavity Anatomy of the Oral Cavity Also called, buccal cavity
Tongue forms floor
Hard and soft palate form roof
Buccal mucosa forms walls
Composed of stratified squamous epithelium
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

11. The Oral Cavity Functions of the Tongue Mechanical processing of food
Manipulation to assist chewing and swallowing
Sensory analysis (taste, texture)
Participation in speech
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

12. The Oral Cavity
The Oral Cavity
玄雍垂
舌繫帶
Figure 16-4(a)

13. The Oral Cavity
The Oral Cavity
Figure 16-4(b)

14. The Oral Cavity Salivary Glands Three pairs of glands
Parotid腮下
Sublingual舌下
Submandibular頷下
Functions of saliva
Lubricates, cleanses oral cavity
Dissolves chemicals
Suppresses bacterial growth
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

15. The Oral Cavity Teeth Participate in mastication咀嚼 of food
Anchored to bone by periodontal ligament牙周韌帶
Dentin象牙質 forms basic shape
Enamel琺瑯質 covers crown
Cementum牙骨質 covers root
20 deciduous teeth (“baby teeth”)
32 secondary teeth (“adult teeth”)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

16. The Oral Cavity Teeth: Structural Components and Dental Succession 牙髓腔齒冠 齒頸 齒根
根管治療
齒槽骨
Figure 16-6(a)

17. The Oral Cavity Teeth: Structural Components and Dental Succession 門牙
側門牙 虎牙
Figure 16-6(b)

18. The Oral Cavity Teeth: Structural Components and Dental Succession
Figure 16-6(c)

19. The Pharynx Functions of the Pharynx
Common passageway for food, drink, and air
Pharyngeal muscles propel food along esophagus toward the stomach during swallowing
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

20. The Esophagus Anatomy of the Esophagus Muscular tube about 25 cm long
Lined by stratified squamous epithelium
Posterior to trachea
Penetrates diaphragm at esophageal hiatus裂縫
Possess upper and lower esophageal sphincters括約肌
Sphincter—A circular band of muscle that can pinch close a muscular tube
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

21. The Esophagus Swallowing (Deglutition)—Three Steps Oral phase
Compaction of bolus食丸
Entry into pharynx
Pharyngeal phase
Elevation of larynx
Bending of epiglottis, closing of glottis
Esophageal phase
Peristalsis pushes bolus toward stomach

22. The Stomach Functions of the Stomach
Temporary storage of ingested food
Mechanical breakdown of food
Forms chyme食靡, a liquid suspension
Breakage of chemical bonds in food by action of acid and enzymes
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

23. The Anatomy of the Stomach噴門 胃底 胃體 小彎
腹腔內膜網 大彎 幽門
Figure 16-8(a)

24. The Phases of Gastric Secretion
The Stomach
The Phases of Gastric Secretion 頭期 胃期
胃蛋白酶原
胃泌素
小腸期
Figure 16-9

25. The Small Intestine Regions of the Small Intestine Duodenum十二指長
Jejunum空腸
Ileum結腸
Ileocaecal valve 迴盲瓣 (a sphincter) marks junction with large intestine
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

26. The Small Intestine The Intestinal Wall
Mucosa has transverse folds, plicae circulares
Plicae have small projections, villi
Both increase surface area of mucosa for absorption
Each villus has a lymphatic capillary, a lacteal乳糜管

27. The Small Intestine
The Intestinal Wall
乳糜管
Figure 16-11(b)

28. The Small Intestine
The Intestinal Wall
Figure 16-11(c)

29. The Small Intestine Intestinal Secretions Intestinal glands secrete
Intestinal juice小腸液
Moistens chyme
Buffers stomach acid
Dissolves digestive enzymes
Dissolves products of digestion
Mucus
Hormones
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

30. The Small Intestine Intestinal Hormones Gastrin Secretin分泌激素
Cholecystokinin (CCK)膽囊收縮素
Gastric Inhibitory Peptide (GIP)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

31. The Small Intestine The Activities of Major Digestive Tract Hormones
Figure 16-12

32. The Small Intestine Digestion in the Small Intestine
Most enzymatic digestion and absorption occurs in the small intestine
Digestive enzymes and buffers are released by:
Pancreas胰臟
Liver
Gall bladder膽囊
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

33. The Pancreas Anatomy of the Pancreas Pancreatic duct enters duodenum
Duct delivers pancreatic juice
Duct branches repeatedly
Fine branches end in pancreatic acini腺細胞
Endocrine cells are found among the acini

34. The Pancreas
The Pancreas
Figure 16-13(b)

35. The Pancreas Secretions of the Pancreas Endocrine secretion (hormones)
Insulin
Glucagon
Exocrine secretion (digestive)
Water
Ions
Enzymes
Carbohydrases
Lipases
Proteases
Nucleases
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

36. The Liver Overview of Liver Largest visceral organ
Over 200 known functions
Four Lobes
Right (largest by far)
Left
Caudate尾
Quadrate正方
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

37. The Surface Anatomy of the Liver
Figure 16-14(b)

38. The Liver
Liver Histology
Figure 16-15(a)

39. The Liver Functions of the Liver Metabolic regulation
Store absorbed nutrients, vitamins
Release nutrients as needed
Hematological regulation
Plasma protein production
Remove old RBCs
Production of bile
Required for fat breakdown
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

40. The Large Intestine Overview of the Large Intestine
Reabsorbs water and compacts feces糞便
Absorbs vitamins made by bacteria
Stores feces before defecation
Consists of three parts
Cecum盲腸:Attaches to vermiform appendix闌尾
Colon結腸
Rectum直腸:Terminates in anal canal
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

41. The Large Intestine The Large Intestine 橫向 下行 上行 結腸袋 迴盲瓣
Figure 16-17(a)

42. The Large Intestine
The Large Intestine
Figure 16-17(b)

43. The Large Intestine Functions of the Large Intestine Absorption
Water
Ions
Vitamins
Organic wastes
Bile salts
Toxins
Bacterial growth
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

44. Digestion and Absorption
Processing and Absorption of Nutrients
Two Steps in Processing
Mechanical processing to break down physical structure of foods
Chemical processing to break the covalent bonds between food subunits
Enzymes catalyze this
Activate the hydrolysis of large food molecules
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

45. Digestion and Absorption
The Digestion and Absorption of Carbohydrates
澱粉酶
Figure 16-18(a) (1 of 2)

46. Digestion and Absorption
The Digestion and Absorption of Carbohydrates
Figure 16-18(a) (2 of 2)

47. Digestion and Absorption
The Digestion and Absorption of Lipids
Figure 16-18(b) (1 of 2)

48. Digestion and Absorption
The Digestion and Absorption of Lipids
Figure 16-18(b) (2 of 2)

49. Digestion and Absorption
The Digestion and Absorption of Proteins
Figure 16-18(c) (1 of 2)

50. Digestion and Absorption
The Digestion and Absorption of Proteins
Figure 16-18(c) (2 of 2)

51. Aging and the Digestive System
Age-Related Changes in the Digestive System
Thinner, more fragile epithelium
Reduced epithelial stem cell division
Weaker peristaltic contraction
Reduced smooth muscle tone
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings