Histology of GI Glands

Question 1

3 types of salivary glands

Answer 1

Parotid
Submandibular
Sublingual

Question 2

Describe the structure of exocrine glands

Answer 2

Duct (coiled, branched, simple)

Secretory units (tubular, acinus)

Duct systems divide and lose epithelial layers as they get smaller

Question 3

2 types of exocrine gland secretions

3 secretory mechanisms

Answer 3

Mucous or serous

Merocrine (exocytosis)
Holocrine (whole cell)
Apocrine

Question 4

General structure of salivary glands

Answer 4

Branched, tubuloalveolar

Question 5

Which salivary gland secretes the most?

Answer 5

Submandibular

Question 6

What type of saliva does the parotid gland secrete?

Answer 6

Amylase-rich

Question 7

What gives the saliva a protective capability?

Answer 7

IgA

Question 8

Describe the type of secretion from each of the salivary glands

Answer 8

Parotid = serous

Submand. = mixed

Sublingual = mucous

Question 9

What does the submandibular gland have that allows it to secrete “mixed” stuff (serous and mucous)?

Answer 9

Serous demilune

Crescent of serous-producing cells

Question 10

3 functions of saliva

Answer 10

3 functions of saliva
Lubricate (mucous)

Protect (antibacterial, antifungal, antiviral)

Digest (amylase and lipase)

Question 11

What enzymes does the parotid gland secrete?

Answer 11

Amylase, peroxidase, lysozyme, antimicrobial proteins

Question 12

Function of submandibular gland

Answer 12

Secrete mucus and amylase for lubrication of food

Question 13

What is unique about the structure of the sublingual gland?

Answer 13

It has multiple small ducts to the oral cavity, not just one

Question 14

What does the sublingual gland secrete?

Answer 14

Mucous

Question 15

The endocrine portion of the pancreas is involved in what?

Answer 15

Glucose metabolism

Question 16

The exocrine portion of the pancreas (more important here) is involved in what?

How does it do that?

Answer 16

Adjusting the pH of the food for the duodenum

Secrete bicarb. and water and mucin

Question 17

2 cell types w/in the exocrine pancreas glands (w/ roles)

Answer 17

Centroacinar cells (duct cells) - bicarb and water

Pancreatic acinar cells - pancreatic enzymes

Question 18

What secretes CCK?

How does it act on the pancreas?

Answer 18

Enteroendocrine cells of duodenum

Binds to pancreatic acinar cells and causes zymogen secretion

Question 19

What are the main zymogens that the pancreatic acinar cells secrete in response to the binding of CCK?

Answer 19

Trypsin, chymotrypsin (inactive)

Amylase, lipase, cholesterol esterase (active)

Question 20

How does diet affect the pancreatic secretions?

What controls this?

Answer 20

Different enzymes secreted based on the food eaten

ANS, regulated by insulin via amylase gene txn

Question 21

Acute pancreatitis

Most common when?

Answer 21

Early activation of pancreatic zymogens w/in the pancreas, causing digestion of pancreas tissue

W/ gallstones or after food/alcohol overload

Question 22

What is the classic structural unit of the liver?

Contents?

Function?

Answer 22

Hepatic lobule (hexagonal)

Branches of all 3 portal triad contents

Arterial and venous blood mixed in sinusoids where hepatocytes filter the blood, then it goes out into central vein

Question 23

What are kupffer cells?

Answer 23

Macrophages of hepatic sinusoids - break down old RBC (2º to spleen)

Question 24

Spaces of Disse

Answer 24

Intermittent spaces in fenestrated epithelium of the sinusoid capillary where basement membrane is absent and blood can flow directly up against the hepatocyte for direct filtering

Question 25

Where does bile come into the picture in a hepatic lobule?

Answer 25

Bile canaliculi run between hepatocytes, perpendicular to hepatocyte rows Bile secretions are sent into the canaliculi --> bile duct

Question 26

Ito cells

Answer 26

Sit w/in Space of Disse and store fat and vitamin A

Question 27

2 domains of the hepatocyte

Answer 27

Apical - face bile canaliculi Basolateral - face sinusoid capillary

Question 28

Functions of the smooth ER w/in hepatocytes (4)

Answer 28

Synthesize cholesterol and bile salts Conjugate bilirubin, steroids, drugs Glycogenolysis Detox lipid-soluble drugs

Question 29

3 important organelles w/in hepatocytes

Answer 29

Smooth ER Rough ER Peroxisomes

Question 30

Function of rough ER / golgi in hepatocytes

Answer 30

Synthesize and glycosylate secretory proteins

Question 31

Function of peroxisomes in hepatocytes

Answer 31

Contains hydrogen peroxidase for breakdown into water and oxygen

Question 32

Functions of bile from liver

Answer 32

Excrete cholesterol, phospholipids, bile salts, conjugated bilirubin, electrolytes Transport IgA to GI mucosa

Question 33

What causes fatty liver? Can lead to what?

Answer 33

Alcoholism - long term alcohol detoxification by hepatocytes Cirrhosis (fibrosis) and carcinoma

Question 34

Function of Gall Bladder

Answer 34

Store, concentrate, and release bile made initially by the liver

Question 35

What happens w/in the cystic duct?

Answer 35

Bile is concentrated as ions and water are reabsorbed

Question 36

Where is bile stored w/in the GB?

Answer 36

In crypts between the villi of columnar epithelium