Glands of GI Histo

Question 1

Ducts and openings in the pancreas

Answer 1

Main pancreatic duct runs through pancreas and empties into duodenum vis major duodenal papilla
Accessory pancreatic duct branches off and empties into duodenum via minor duodenal papilla

Question 2

How does bile get into the duodenum

Answer 2

From liver via common hepatic duct
From gallbladder via cystic duct
They join to form common bile duct
Joins into main pancreatic duct and empties via major duodenal papilla

Question 3

Exocrine pancreas

Answer 3

Acinar cells secrete digestive enzymes into a duct system
Darkly staining on H&E
Compound tubuloacinar gland and serous gland

Question 4

Endocrine pancreas

Answer 4

Islets of Langerhans produce hormones that regulate blood glucose (most numerous in the tail)
Pale staining
Islets are richly vascularized
Incomplete layer of delicate CT surrounds islets
Loose CT supports the cells within the islets

Question 5

Duct system in the exocrine pancreas

Answer 5

Centroacinar cells inside the acinus that produce bicarb and water
Intercalated ducts also make bicarb and water
Intralobular ducts inside the lobule, more cuboidal
Interlobular ducts outside the lobule, more columnar
Main pancreatic duct

Question 6

5 different cells in the islet

Answer 6

Alpha (glucagon)
Beta (insulin)
Delta (somatostatin)
F cells (pancreatic polypeptide)
Epsilon

Question 7

3 ways to see different cell types in islets

Answer 7

Special stains
Immunofluorescence
TEM

Question 8

Somatostatin

Answer 8

Inhibits insulin and glucagon secretion

From delta cells

Question 9

4 functions of the liver

Answer 9

Exocrine (makes bile)
Endocrine (plasma protein synthesis)
Metabolism and detoxification
Storage (iron, blood, glycogen, lipid, vitamins)

Question 10

Hepatic portal vein

Answer 10

Carries blood from the gut to the liver

Partially deoxygenated, but nutrient rich

Question 11

Portal triad (tract)

Answer 11

Proper hepatic artery (arteriole)
Hepatic portal vein (venule)
Hepatic duct (bile ductules)

Question 12

Components of a hepatic lobule

Answer 12

Central vein
6 septa form borders
6 portal triads at the corners
Sinusoids radially to central vein

Question 13

Perivenular vs periportal

Answer 13

Perivenular: around the central vein
Periportal: around the portal triad

Question 14

Capsule of the liver is called…

Answer 14

Glisson capsule

Question 15

Bile canaliculus

Answer 15

Intercellular tunnel sandwiched between adjacent hepatocytes
Sealed by tight junctions to prevent bile leakage
Bile secreted by hepatocytes into canaliculi progressively flows into bile ductules at periphery of lobules

Question 16

Space of Disse

Answer 16

Between hepatocytes and the endothelial cells

Where quiescent Stellate cells are found

Question 17

Kupffer cells

Answer 17

Macrophages of the liver
Found in the sinusoids
Other side of the endothelial cells from the space of Disse
Part of the sinusoidal wall

Question 18

Stellate cells

Answer 18

Found in the space of Disse
Store vitamin A in lipid droplets
~ fibroblasts

Question 19

Lysosomes

Answer 19

Contain hydrolytic enzymes
Degrade cellular debris and pathogens
Appearance varies with amount of accumulated debris

Question 20

Lipid droplets

Answer 20

Circular, non-membranous inclusions
Storage for energy and metabolism
Insulation and padding (adipocytes)
Store lipid and cholestrol for synthesis of other macromolecules
May also be a sign of pathological changes

Question 21

Gallbladder epithelium

Answer 21

Simple columnar epithelium
Active in water transport to concentrate bile
Basal nuclei
Striated border
Lamina propria is richly vascularized

Question 22

Path of the ducts in the pancreas

Answer 22

Centroacinar cell
Intercalated ducts
Join to form intralobular ducts
Outside the lobule form interlobular ducts