Chapter 14 Digestive gland

1. Chapter 14 Digestive gland

2. ---small gland: fundis gland, small intestinal gland ---large gland: salivary gland, pancreas, liver

3. 1. Salivary gland

4. 1) General structure of exocrine gland ---Capsule: CT, which separate the parenchyma into lobules ---lobule:

5. ① acinus: a. serous acinus: structure: • pyramidal or cuboidal • round basally-located N • apical: zymogen granule-acidophilic • basal: basophilic-RER, ribosome function: secret salivary amylase（淀粉酶）

6. b. mucous acinus: structure: • pale-stained, slight-blue, flattened N against the basal membrane • mucinogen granule • Golgi, RER, mitochondria

7. c. mixed acinus: several serous cell attached to mucous acinus – serous demilune

8. ②duct: • intercalated duct: • simple squamous epi. • simple cuboidal epi. • connect with acinus

9. b. striated duct (secretory duct): intralobule • simple columnar epi. : • tall cell, acidophilic • round N, located at apical part • longitudinal striation: plasma membrane infolding

10. c. interlobular duct and major duct : simple columnar epi. or pseudostratified ciliated columnar epi.

11. 2) structural feature of each salivary gland a.    parotid gland: -serous -long intercalated duct, short striated duct

12. b.       submandibular gland: -mixed( mainly serous, less mucous and mixed) -short intercalated duct, long striated duct

13. c.       sublingual gland: -mixed(mainly mucous, more serous and mixed) -more demilunes, no intercalated duct, under-developed striated duct

14. 胰腺-图 2. Pancreas

15. ---capsule: CT, septa ---parenchyma: /exocrine pancreas /endocrine pancreas

16. 1)exocrine pancreas ---acinus: serous

17. centroacinar cell: small, pale cell with round or ovoid N, derived from epithelial cell of intercalated duct

19. ---duct: long intercalated duct ---function: secret pancreatic liquid 1-2L/D, PH 7.8-8.4 Digestive enzymes: trypsinogen（胰蛋白酶原）, amylase（淀粉酶） ,lipase（脂酶） and chymotrypsinogen（糜蛋白酶原）,

20. 2) endocrine pancreas( pancreas islet) ---170.000-200.000, constitute about 1% of total pancreas volume ---75-500 um ---HE: cells arranged into cord with CT rich in fenestrated cap.

21. a.   A cell: • 20%. Large polygonal in shaped, peripheral-distributed • EM: secretory G: large, 190-310 nm, round with dense core • function: secret glucogon（高血糖素） - 29 amino acid residues protein ↓ glycogen→ glucose

22. A cell

23. b.   B cell: • 75%, small, centrally-distributed • EM: secretory G: different diameter, 225-375 nm with one or several dense core • function: secret insulin - 51 amino-acid residues

24. B cell

25. c. D cell: • 5%, ovoid, fusiform, peripheral-distributed, between A, B cells • EM: -gap junction with A,B cell -secretory G: large, 190-370nm, low-density core • function: secrete somatostatin（生长抑素） to inhibit the secreting of A, B, PP cell

27. d. PP cell: • EM: secrete granule: small, 110-170 nm • function: secrete pancreatic polypeptide （胰多肽）to inhibit the secreting of pancreatic liquid, movement of viscera and contraction of gall bladder

29. e. D1 cell: 2-5%, peripheral, irregular EM: small, 140-190 nm, function: secrete VIP (vasoactive intestinal peptide，血管活性肠肽) f. C cell: undifferentiated cell

30. 肝-图 3. Liver

31. ---largest, 2% of body weight ---capsule: DCT, insert into parenchyma to separate the parenchyma into hepatic lobule ---hepatic lobule ---portal area

32. 1) hepatic lobule: basic structural unit ---500，000-1，000，000 ---2 mm long, 1 mm in across D ---polygonal (irregular) ---structure: • central vein • hepatic plate: radiating arranged • hepatic sinusoid

33. ①     Central vein: • small vein: endothelium + CT • 45 um • receive the blood from sinusoids

34. ②    Hepatic plates ---formed by single layer of hepatocytes

35. a. hepatocyte: LM: polygonal, 20-30 um eosinophilic N: -large, pale, round, centrally- located -1/4 binucleate

36. EM: • mitochondria: 1000-2000, 20% total volume • RER: involve in the synthesis of albumin, fibrinogen, clotting factor, lipoprotein and complement protein • SER: contain enzymes- oxidoreductase氧化还原酶 (oxidase, reductase), hydrolase, transterase, synthetase, involve in the formation of bile and the metabolism of adipose, glucose and hormones

37. Golgi apparatus: involve in -formation of bile -process, condense and storage of proteins -formation of lysosome • Lysosome: involve in phagocytosis activity and metabolism of bilirubin（胆红素） • microbody: -round, 0.2-1.0 um -contain catalase （过氧化氢酶）and peroxidase（过氧化物酶） • inclusions: glycogen, lipid droplet, pigment

38. b. bile canaliculus: ---cell membrane of adjacent hepatocytes depress to form a tubular system between hepatocytes

39. ---structure: • silver preparation: dark-brown colored network • 0.5-1um • Microvilli • tight junction, desmosome

40. ③ Hepatic sinusoid ---space between hepatic plates ---structure:

41. 9-12 um endothelial cell: fenestrated, gap, plasmalemmal vesicles -liver macrophage (Kupffer cell) -large granular lymphocyte: NK cell

42. Perisinusoidal space: Disse space - narrow space between endothelial cell and hepatocytes • 0.4 um width; blood plasma • microvilli; RF • fat-storing cell:

43. fat-storing cell: -irregular, with processes -EM: large lipid droplets, RER, mito, Golgi -function: storage of vitamin A(E,K), synthesis of collagen

44. The three kinds of different surfaces of hepatocytes ---face adjacent cell each other: 55% ---face the sinusoids: 35% ---form bile canaliculus: 10%

45. 2) portal area ---areas(triangle-shaped or irregular-shaped) where adjacent hepatic lobules meet ---contains CT and several ducts

46. a.   interlobular arteries: • branches of hepatic A • small A: endothelium + 3-4 layers of SM b.   interlobular vein: • branches of portal vein • small vein: endothelium + less CT and single SM c.   interlobular bile duct: • simple cuboidal or low columnar epi.

47. 3) Blood circulation of liver hepatic A →interlobular A →terminal hepatic arteriole portal V→interlobular V→terminal portal venule → hepatic sinusoid →central vein→sublobular V →hepatic V→inferior vena cava ) ｛

48. Blood circulation of liver 门V 小叶间V 终末门微V 血窦 小叶下V 中央V 肝A 小叶间A 终末肝微A 肝V

49. 4) Passage of bile • 肝细胞 胆小管 闰管 小叶间胆管 左右肝管 肝总管 胆囊管 胆囊 或经胆总管到十二指肠

50. 谢谢！