1. In the name of God
Digestive gland
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2. Digestive Glands Digestive glands are consist of: Salivary glands
Dr. Maria Zahiri
Digestive glands are consist of:
Salivary glands
Pancreas
Liver
Gall bladder

3. Salivary Glands minor (Accessory) salivary glands
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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

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

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6. Salivary Gland Cells Serous cells produce proteins pyramidal cells
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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

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

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Organized as acinus or demilune that secrete proteins, polysaccharides and ptyalin

11. Ducts system Intercalated duct smallest branches
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Ducts system
Intercalated duct
smallest branches
short, cuboidal or squamous cells and myoepithelial cells
Striated duct
Larger diameter
cuboidal to low columnar cells which are eosinophilic, and secrete fluid and ions
basolateral membrane folded with Na – ATPase pump, elongated mitochondria

12. interlobular ducts (excretory ducts):
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intralobular ducts:
Striated ducts join each other and forming intralobular ducts that are invested by more CT elements
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

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15. Myoepithelial cells (Basket cells)
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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

16. Parotid Gland The largest salivary gland produce 30% of saliva
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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

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

18. Sublingual Gland It is very small that produce 5% of total saliva
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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

19. Saliva Saliva includes water, enzymes, IgA, mucous, ions
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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

20. Pancreas is a mixed exocrine and endocrine gland
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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, intercalated ducts, Intralobular ducts, and interlobular ducts

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23. Liver largest gland in the body (1500 gr)
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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

24. Liver hepatocytes Liver has a lobular organization
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Liver
hepatocytes
Liver has a lobular organization
Classical lobule: hepatocytes arranged as an hexagon
Portal area (triad):
is where three classical lobules are in contact with each other, more CT elements present,
houses branches of hepatic artery,
tributaries of portal vein,
interlobular bile ducts, and lymph
vessels

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26. classical lobule
blood flow from periphery to center of lobule
Bile flow in opposite direction in small intercellular spaces known as bile canaliculi
Portal lobule
Is a triangular region that portal area is located in its center and central veins form apices of the triangle
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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29. Liver
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
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)

31. 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,

32. 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

34. 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

36. 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

37. Gall Bladder Mucosa : simple columnar epithelium
Epithelial layer is highly folded
lamina propria:
loose CT
Smooth muscle layer is composed of thin obliquely oriented fibers with perimuscular connective tissue
Serosal and adventitial membrane
Stores and concentrates ml bile
Cholecystokinin and acetylcholine stimulates contraction to force bile into small intestine

39. Dr. Maria Zahiri
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