1. Digestive gland
Dr. Maria Zahiri

2. Digestive Glands Digestive glands are consist of: Salivary glands
Pancreas
Liver
Gall bladder
Dr. Maria Zahiri

3. Salivary Glands minor (Accessory) salivary glands
pairs of major (main) salivary glands
Three pairs of major salivary glands are:
Submandibular glands
Sublingual glands
Parotid glands
Dr. Maria Zahiri

4. Salivary Glands capsule and septa
that organize the glands into lobes and lobules
Dr. Maria Zahiri

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6. Salivary Gland Cells Serous cells produce proteins pyramidal cells
spherical euchromatic nucleus
Cytoplasm is basophilic (RER, Golgi apparatus)
Apically located granules that are usually eosinophilic
Many basal mitochondria
Dr. Maria Zahiri

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8. heterochromatic basal flattened nucleus Apical cytoplasm is pale
Mucous cells
cuboidal or pyramidal
heterochromatic basal flattened nucleus
Apical cytoplasm is pale
They have less RER, fewer mitochondria but greater GA
Dr. Maria Zahiri

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10. MIXED GLAND
Organized as acinus or demilune that secrete proteins, polysaccharides and ptyalin
Dr. Maria Zahiri

11. Ducts system : Intercalated ducts diameter: thinnest
wall: simple low cuboidal epithelium

12. Striated duct (secretory duct)
wall: simple columnar epithelium; the nucleus is near the cell apex
cytoplasm is acidpphilic; has basal striations
EM: the basal striations created by membrane infolding and mitochondia
reabsorbing sodium and excreting potassium;
transport water and ions

13. Intercalated ducts and striated ducts

14. intralobular ducts:
Striated ducts join each other and forming intralobular ducts that are invested by more CT elements
Dr. Maria Zahiri

15. interlobular ducts (excretory ducts):
intralobular ducts join each other and forming larger caliber ducts known as interlobular ducts (excretory ducts)
Excretory duct have large diameter, large lumen, cuboidal or columnar cells, located outside of lobules
Dr. Maria Zahiri

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18. Myoepithelial cells (Basket cells)
have large processes which form desmosomal contact with acini and ducts cells,
Their processes are rich in actin and myosin
have a common basal lamina with acinar cells
They attach to basal lamina by hemidesmosome
Dr. Maria Zahiri

19. Parotid Gland The largest salivary gland produce 30% of saliva
capsule & many septa divided the glands into lobes and lobules
serous cells
After 40 year of age adipose
tissue invaded the gland
Dr. Maria Zahiri

20. Submandibular Gland produce 60% of saliva
Mucous and serous acini; mucous acini with limited number of serous demilunes
About 80% of cells are serous (basophilic)
Dr. Maria Zahiri

21. Sublingual Gland It is very small that produce 5% of total saliva
Mostly mucous cells in acini with some serous demilunes
Produce mix saliva but mostly mucous saliva
Dr. Maria Zahiri

22. Saliva Saliva includes water, enzymes, IgA, mucous, ions
Moisten and lubricate food for swallowing
Enzymes like amylase and lipase to begin digestion
Saliva has protective effect on oral cavity tissues
Participate in taste sensation
IgA, lactoferrin, lysozyme have different role against antigens and microorganisms
Dr. Maria Zahiri

23. Pancreas is a mixed exocrine and endocrine gland
Thin capsule with septa between lobules
Exocrine part organized similar to parotid gland
Endocrine part are islets of Langerhans scattered among the excretory units
Centroacinar cells occupy the lumen of the acini, these cells are beginning of the duct system
Centroacinar cells are pale, low cuboidal
intercalated ducts, Intralobular ducts, and interlobular ducts
no striated duct
Dr. Maria Zahiri

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26. The functions of exocrine portion
Secret abundant trypsinogen, chymotrypsinogen, amylase, lipase, sodium bicarbonate and trypsin inhibitor

27. Endocrine portion (pancreatic islet):
rounded clusters of cells embedded within exocrine pancreatic tissue are divided into three kinds of cells: A, B, and D cells
fenestrated capillaries are among the cells

28. Pancreas (show pancreatic islet)

29. Endocrine portion Size number Distribution Function A cells large 20%
Peripheral
glucagon
B cells
small
75%
center
insulin
D cells 5%
Among A and B cells
somatostatin
PP cells: pancreatic polypeptide
G cells: gastrin
Other cells

30. A cells
B cells
D cells

31. Liver largest gland in the body (1500 gr)
has endocrine and exocrine functions
Receives portal blood from intestine via portal vein and oxygenated blood from hepatic arteries
Dr. Maria Zahiri

32. Liver Hepatic plates Sinusoid Central vein Liver lobule
Interlobular arteries
Interlobular veins
Interlobular bile ducts
Portal area

33. classical lobule
blood flow from periphery to center of lobule
Bile flow in opposite direction in small intercellular spaces known as bile canaliculi

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37. Portal lobule
Is a triangular region that portal area is located in its center and central veins form apices of the triangle

38. Hepatic acinus (acinus of Rappaport)
is diamond-shaped, a distributing artery located in center of acinus, three regions of parenchyma surrounding the artery(zone I, II, III)

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40. The space between the anastomosing plates of hepatocytes are occupied by hepatic sinusoids
Sinosuidal lining cells are fenestrated are not in contact with each other
They prevent direct contact between blood and hepatocytes
Resident macrophages known as Kupffer cells associated with lining cells

41. The space that separates sinusoidal lining cells from hepatocytes is called perisinusoidal space (space of Disse)
Microvilli of hepatocytes occupy much of the space
Type III collagen that is present in space support lining cells(no basal lamina)

42. Cells
Fat storing cells ( known as Ito cells or Stellate cells) may present in Disse space and store vitamin A
Pit cells which are natural killer cells also may be seen in space of Disse
Hepatocytes are polygonal
forming anastomosing plates of one to two thickness cells, eosinophilic with 1 or 2 spherical nuclei,

43. Cells
In lateral domain bile canaliculi form between two cells, microvilli, Na-K ATPase and gap junctions are common characteristics of lateral domain
Bile canaliculi between hepatocytes leading to hepatic ducts with simple cuboidal epithelium

44. Hepatic cords

45. Liver
Sinunosoidal domains of cell membrane have many microvilli protrude to perisinusoidal space (of Disse), endocrine secretion of hepatocytes release here
Bile secreted from hepatocytes into bile canaliculi contains water, ions, bile salts and acids, phospholipids, cholesterol, & bilirubin

47. Liver Functions Glycogen storage Lipid metabolism
Vitamin storage (A, D, B12 )
Bile production (Bile acids solubilize lipids and aid digestion)
Detoxification of drugs and toxins in SER
Synthesis of plasma proteins (albumin)
Metabolism of lipid, carbohydrate, proteins
Erythrocyte breakdown (Bilirubin formed in breakdown of RBC)
Complex IgA with secretory component

48. Mitochondria
provide the energy for the hepatocytes
Rough endoplasmic reticulum
synthesize some plasma proteins
Golgi apparatus
participate in the formation of bile and lipoprotein

49. Smooth endoplasmic reticulum
synthesize bile, triglyceride and LDL
metabolism of the lipid, hormones
inactivate steroid hormone
biotransformation of some materials
detoxification of Toxic substances

50. Lysosomes
actively participate the metabolism of
hepatocyte and renewal of organelles
play a role in metabolism
storage of iron

51. Microbodies
detoxification: catalase and peroxidase;
reduce the hydrogen peroxide into H2O
Inclusions
include glycogen, lipid droplets, pigment etc;
These contents vary according to physiologic state of human body

52. Bile canaliculi between two adjacent hepatocytes
the membrane of hepatocyte projects to the lumen, forming many microvilli
the cell membranes near the bile canaliculi are firmly bound by junctional complexes

53. Liver sinusoid spaces between the hepatic plates irregular in shape
composed of only one discontinuous layer of fenestrated endothelial cells, no diaphragm,
no basement membrane
Kupffer cells are located within the sinusoid cavities

54. Blood circulation: （functional vessel) (nutrient vessel) portal V.
interlobular V.
（functional vessel)
sinusoids
central V.
hepatic A.
interlobular A.
sublobular V.
(nutrient vessel)
hepatic V.

55. Discharge way of bile: Bile canaliculi Hering’s canals
Interlobular bile ducts
Gallbladder
Hepatic duct
Common bile duct
Cystic duct
duodenum

56. Gallbladder Simple columnar Epi. , no Goblet cells
Laminar propria: C.T.
mucosa
muscle layer: composed of an inner circular,
an outer longitudinal layers of smooth muscle
adventitia: most are fibrosa, some are serosa

57. Gallbladder

58. Stores and concentrates 30-50 ml bile
Cholecystokinin and acetylcholine stimulates contraction to force bile into small intestine

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