Exocrine Pancreas and Salivary Gland Physiology

Question 1

What are the components of saliva and their functions?

Answer 1

• water: facilitates taste, dissolution, and swallowing
• bicarbonate: neutralizes acid
• mucins: lubrication for swallowing
• amylase: starch digestion (alpha-1,4 bonds)
• lysozyme, lactoferrin, and IgA: innate and acquired immune protection
• epidermal and nerve growth factors: mucosal growth and protection

Question 2

Describe the anatomy of the salivary gland.

Answer 2

The acinus is surrounded by acinar cells which themselves are surrounded by myoepithelial cells (for contracting). The route out of the acinus is the intercalated duct, leading to the striated duct.

Question 3

Which two ganglia receive PNS input that induces salivary secretion?

Answer 3

Octic and submandibular

Question 4

True or false: SNS stimulation leads to inhibition of salivary secretion.

Answer 4

False. SNS, like PNS, leads to increased secretions, but it leads to protein rich, fluid low secretions.

Question 5

Increased blood flow has what effect on salivary concentration?

Answer 5

It increases fluid concentration.

Question 6

The ductal cells do what to saliva?

Answer 6

Reabsorb NaCl and secrete KHCO3

Question 7

What does increased saliva flow rate do to ionic concentration (of saliva)?

Answer 7

Increased flow increases concentration of NaCl and HCO3

Question 8

Where, in the pancreas, are bicarb secretions produced?

Answer 8

In the ductal cells

Question 9

What is CCK?

Answer 9

Cholecystokinin

Question 10

Acetylcholine is released by ____________ when _____________.

Answer 10

vagal nerves of the enteric nervous system; food is seen (i.e., the cephalic phase)

Question 11

Secretin is released by ______________ when ______________.

Answer 11

endocrine cells of the proximal small intestine; acid arrives in the proximal small intestine

Question 12

CCK is released by _______________ when ______________.

Answer 12

endocrine “I” cells in the proximal small intestine; fats arrive in the proximal small intestine

Question 13

True or false: there are myoepithelial in the pancreatic acini.

Answer 13

False!

Question 14

What four things does CCK do?

Answer 14

• stimulates contraction in the gallbladder
• stimulates slowing of gastric emptying
• stimulates secretion of zymogens from pancreas
• stimulates relaxation of the sphincter of Oddi

Question 15

Comparing to the salivary glands, how does flow rate differ for pancreatic secretions?

Answer 15

With increased flow rate, concentrations of Na and HCO3 rise, but chloride and potassium fall. (This is different from the saliva in that increased salivary flow rate increases Cl content.)

Question 16

Salivary secretions are regulated by ____________, while the pancreatic secretions are regulated by _____________.

Answer 16

the ANS; ANS and hormones

Question 17

Which part of the salivary gland is impermeable to water?

Answer 17

The ducts

Question 18

The three types of benign salivary neoplasms are ____________.

Answer 18

• pleomorphic adenoma
• monomorphic adenoma
• ductal papilloma

Question 19

Papillary projections are a problem in which cancer?

Answer 19

Pancreatic exocrine (they can break off and occlude things)

Question 20

There are two kinds of cells in the acini of salivary glands. List them and their functions.

Answer 20

• Serous: secrete water, electrolytes, and enzymes

- Mucous: secrete mucins

Question 21

In the pancreatic duct, chloride passes into the lumen via ___________ transport, while sodium and water pass into the lumen via ________.

Answer 21

active; paracellular movement

Question 22

The three molecules that can stimulate pancreatic secretions are ___________.

Answer 22

secretin, acetylcholine (from the vagus nerve), and cholecystokinin

Question 23

This neoplasm is typically encapsulated, but tumor islands can exist in the capsule.

Answer 23

Pleomorphic adenoma

Question 24

This neoplasm has lymphocytic germinal centers, but must also have oncocytic epithelium for diagnosis.

Answer 24

Warthin’s tumor

Question 25

How can you distinguish a basal cell adenoma from a pleomorphic adenoma?

Answer 25

Basal cell adenomas will not have stroma and their cells will be arranged in a uniform pattern.

Question 26

Which pancreatic cancer is most common in children younger than age 10?

Answer 26

Pancreatoblastoma

Question 27

The most common benign parotid-gland tumor originates from which cells?

Answer 27

Intercalated cells (this being pleomorphic adenoma)

Question 28

The most common malignant parotid-gland tumor originates from which cells?

Answer 28

Excretory cells