Histology - Digestive Accessory Organs

Front 1

Intercalated vs Striated Ducts

Back 1

Intercalated vs Striated Ducts:

-Intercalated Ducts collect secretions from serous & mucous acinus
-Multiple Intercalated Ducts converge forming a Striated Duct

Front 2

Submandibular Gland

Back 2

Submandibular Gland:

Mixed:
-90% Serous
-10% Mucous

*Mucous Tubules have Serous Demilune (Acinar) caps

Front 3

Sublingual Gland

Back 3

Sublingual Gland:

Mixed:
-Primarily Mucous
-Some Serous

Front 4

Parotid Gland

Back 4

Parotid Gland:

-Exclusively Serous
-produces majority of saliva
-produces Amylase

Front 5

Exocrine Pancrease

Back 5

Exocrine Pancreas: (~90% exocrine)

-Exclusively Serous
-Compound Acinar Gland
-Islets of Langerhans: endocrine cells (~10%)

*Serous Acinar cells full of zymogen granules containing proenzymes

*Under Control of Endocrine Hormones:
-Cholecystokinin --> stimulate release of digestive enzymes from acinar cells
-Secretin --> stimulate secretion of water & bicarbonate

*Pancreatic Acinus
-Serous Acinus
-Intercalated Ducts penetrate into Acinus (called Centroacinar Cells)

Intercalated Ducts secrete Bicarbonate
No striated ducts in pancreas

Front 6

Exocrine Pancrease

Back 6

Exocrine Pancreas:

-Exclusively Serous
-Islets of Langerhans: endocrine cells

*Serous Acinar cells full of zymogen granules containing proenzymes

*Pancreatic Acinus
-Serous Acinus
-Intercalated Ducts penetrate into Acinus (called Centroacinar Cells)


*Under Control of Endocrine Hormones:
-Cholecystokinin --> stimulate release of digestive enzymes from acinar cells
-Secretin --> stimulate secretion of water & bicarbonate from duct cells

Front 7

Pancreatic Enzymes

Back 7

Pancreatic Enzymes:


Zymogen granules of the acinar cells contain digestive enzymes in inactive/proenzyme form:
a) Proteases
-trypsinogen
-chymotrypsinogen
-procarboxipeptidase
b) Lipases
c) Amylase
d) Nucleus

-Trypsinogen activated by enteropepdiase
-Trypsin activates other enzymes

Front 8

Glisson's Capsule

Back 8

Glisson's Capsule:

Capsule surrounding liver

Front 9

Liver Lobule

Back 9

Liver Lobule:

-Hexagonal Shape
-Organized around Central Vein:
Corners: Portal Triad
-branch portal venule
-branch hepatic artery
-branch bile duct

*Hepatocytes makeup parenchyma, with sinusoid space

*Blood flows towards the center
*Bile flows towards the edge

Front 10

Kupffer Cell

Back 10

Kupffer Cell:

-in the Liver sinusoid
-immune cell - phagocytosis

Front 11

Ito Cell

Back 11

Ito Cell:
-in the liver, Space of Disse (perisinusoidal space)
-(between capillary endothelium & hepatocyte)

-Vitamin A storage within lipid droplets

-Toxic Liver Injury - in response, Ito cells convert into fibroblast like cells leading to fibrosis of the liver = liver cirrhosis
-normal liver tissue replaced by fibrotic connective tissue

Front 12

Bile Canaliculi

Back 12

Bile Canaliculi:

-small space between hepatocytes

Bile Canaliculi --> Bile Ductule --> Bile Duct

Front 13

Gallbladder

Back 13

Gallbladder:

-simple columnar epithelium
-storage, concentration & release of bile

-Cholecystokinin triggers opening of Sphincter of Odi