Chapter 43 Flashcards
What are the 2 exocrine glands?
The pancreas and the salivary glands
What are acinar cells?
Specialized protein-synthesizing cells
What are duct cells?
Epithelial cells that are specialized for fluid and electrolyte transport
What are goblet cells?
Produce mucin in exocrine glands (pancreas, salivary glands)
How is acinar cell secretion regulated?
Cholecystokinin and muscarinic receptors
What is the major second messenger system that controls secretion from acinar cells?
Ca2+
What are the 4 second messenger systems of acinar cells?
Ca2+, cAMP, cGMP, and effectors
In addition to proteins, what else do acinar cells secrete?
A plasma-like fluid
The pancreatic duct cell secretes?
Secretes isotonic NaHCO3
Secretin works through which second messenger system in the pancreatic duct cell?
cAMP
Acetylcholine works through which second messenger system in the pancreatic duct cell?
Ca2+
Secretin and acetylcholine both stimulate what end result in the pancreatic duct cell?
HCO3- secretion
Which channels on the apical border of the pancreatic duct cell is important for neurohormonal regulation?
Chloride channels
What else can pancreatic duct cells secrete besides isotonic bicarbonate?
Glycoproteins
What is pancreatic juice?
A protein-rich, alkaline-rich solution
In the fasting state, the concentrations of pancreatic enzymes ___?
Oscillate at low levels
Duodenal I cells secrete what?
Cholecystokinin
Cholecystokinin from duodenal I cells stimulate what?
Enzyme secretion by the acini cells
S cells secrete what?
Secretin
Secretin secretion from S cells stimulates what?
HCO3- and fluid secretion by the duct cells
A meal triggers what 3 phases?
- Cephalic phase
- Gastric phase
- Intestinal phase
The digestive enzymes in the pancreas digest what food molecules?
Carbohydrates and proteins, but not lipids
What can inhibit pancreatic secretion?
Fat that enters the distal part of the small intestine
What are the two most important neural pathways for acinar cell secretion?
Cholinergic and adrenergic neural pathways
What two second messenger systems stimulate acinar cell secretion?
cAMP and Ca2+
What do salivary duct cells produce?
Hypotonic fluid that is rich in KHCO3 and poor in NaCl
Salivary cells can secrete and also reuptake what?
Proteins
Parasympathetic stimulation of salivary cells causes what?
Decreases Na+ reabsorption
What happens when salivary cells are stimulated by aldosterone?
Increases in Na+ reabsoprtion
Based on protein concentrations of saliva, what are the 3 types of secretions from salivary cells?
Serous, seromucous, or mucous
What is the composition of saliva when there is low flow rate?
Hypotonic and rich in K+
What is the composition of saliva when there is a high flow rate?
Plasma level tonicities
Salivary secretion increases with sympathetic or parasympathetic stimulation?
Parasympathetic stimulation
