Exocrine Pancreas and Salivary Gland Physiology Flashcards
What are the components of saliva and their functions?
- 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
Describe the anatomy of the salivary gland.
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.
Which two ganglia receive PNS input that induces salivary secretion?
Octic and submandibular
True or false: SNS stimulation leads to inhibition of salivary secretion.
False. SNS, like PNS, leads to increased secretions, but it leads to protein rich, fluid low secretions.
Increased blood flow has what effect on salivary concentration?
It increases fluid concentration.
The ductal cells do what to saliva?
Reabsorb NaCl and secrete KHCO3
What does increased saliva flow rate do to ionic concentration (of saliva)?
Increased flow increases concentration of NaCl and HCO3
Where, in the pancreas, are bicarb secretions produced?
In the ductal cells
What is CCK?
Cholecystokinin
Acetylcholine is released by ____________ when _____________.
vagal nerves of the enteric nervous system; food is seen (i.e., the cephalic phase)
Secretin is released by ______________ when ______________.
endocrine cells of the proximal small intestine; acid arrives in the proximal small intestine
CCK is released by _______________ when ______________.
endocrine “I” cells in the proximal small intestine; fats arrive in the proximal small intestine
True or false: there are myoepithelial in the pancreatic acini.
False!
What four things does CCK do?
- stimulates contraction in the gallbladder
- stimulates slowing of gastric emptying
- stimulates secretion of zymogens from pancreas
- stimulates relaxation of the sphincter of Oddi
Comparing to the salivary glands, how does flow rate differ for pancreatic secretions?
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.)
Salivary secretions are regulated by ____________, while the pancreatic secretions are regulated by _____________.
the ANS; ANS and hormones
Which part of the salivary gland is impermeable to water?
The ducts
The three types of benign salivary neoplasms are ____________.
- pleomorphic adenoma
- monomorphic adenoma
- ductal papilloma
Papillary projections are a problem in which cancer?
Pancreatic exocrine (they can break off and occlude things)
There are two kinds of cells in the acini of salivary glands. List them and their functions.
- Serous: secrete water, electrolytes, and enzymes
- Mucous: secrete mucins
In the pancreatic duct, chloride passes into the lumen via ___________ transport, while sodium and water pass into the lumen via ________.
active; paracellular movement
The three molecules that can stimulate pancreatic secretions are ___________.
secretin, acetylcholine (from the vagus nerve), and cholecystokinin
This neoplasm is typically encapsulated, but tumor islands can exist in the capsule.
Pleomorphic adenoma
This neoplasm has lymphocytic germinal centers, but must also have oncocytic epithelium for diagnosis.
Warthin’s tumor
How can you distinguish a basal cell adenoma from a pleomorphic adenoma?
Basal cell adenomas will not have stroma and their cells will be arranged in a uniform pattern.
Which pancreatic cancer is most common in children younger than age 10?
Pancreatoblastoma
The most common benign parotid-gland tumor originates from which cells?
Intercalated cells (this being pleomorphic adenoma)
The most common malignant parotid-gland tumor originates from which cells?
Excretory cells
