Salivary and Pancreatic Secretions Flashcards
What does saliva contain?
Mucus, H2O, HCO3-, and enzymes: Amylase, Lipase, Lysozyme
What is Lysozyme?
An antibacterial enzyme found in tears and nasal secretions
Which nervous pathway stimulates salivary secretion?
Both parasympathetic and sympathetic
- para is stronger
What is Sjogrens syndrome?
Infiltration of WBC and immune complexes, which causes dysfunction of endocrine glands
How is sjogrens treated?
H20 and fluoride
What does Enterokinase do?
Splits Trypsinogen to form Trypsin
Which part of the pancreas secretes HCO3-?
Epithelial cells of the pancreatic duct
What stimulates pancreatic secretions?
Secretin and CCK, both of which are released by EEC cells in SI and the presence of FAs and AAs acting on afferent neuronal endings in the duodenum
- Also taste of food, or distention of stomach
What does Secretin do to the pancreas?
Stimulates HCO3- secretion
- stimulated by high acidity in duodenum
What does CCK do to the pancreas?
Stimulates acinar cell secretion
- stimulated by the presence of FAs and AAs in the duodenum
Where does the R factor for B12 come from?
Saliva
What is alpha amylase
Begins digestion of polysaccharides in the mouth, acts at pH 6.7
What transporters are located on the basolateral surface of acinar cells?
Na+/K+/2Cl- in
K+/Na+ATPase
K+ leak channels
What transporters are located on the apical surface of acinar cells
Cl- into the lumen
- Attracts Na+ between the cells
What is the initial saliva like?
Isotonic, similar concentrations to plasma causing water to follow
What is the ductal saliva like?
Hypotonic because NaCl is reabsorbed
- more ions leave saliva than H20
- epithelium is impermeable to water
Effect of flow rate on saliva
More flow, such as before meal, means it becomes more isotonic as it has less time to interact with the ductal epithelium
Ampulla of Vater
Convergence site of common bile duct and pancreatic duct
Pancreatic secretions during the cephalic phase
Central impulses such as sight, or eating trigger vagal stimulation
- This causes the release of 25-50% and minor gastrin secretion
Pancreatic secretions during the gastric phase
Distention triggers the vago-vagal reflex arc
- 10% of PS
- minor Gastrin secretion
Pancreatic secretions during the intestinal phase
AAs, FAs, peptides trigger vago-vagal reflex, CCK release and Secretin release
- 50-100% of PS
What is Potentiation?
Ach, CCk and Secretin are all required to achieve pancreatic release
What happens in Acute Pancreatitis?
Premature activation of zymogens, acinar cell necrosis, pancreatic auto-digestion, disruption of paracellular barrier allows protease escape
What transporters are located on the apical surface of ductal cells?
HCO3-/Cl- exchanger
CFTR Cl- out
What’s on the basolateral surface of ductal cells?
Na+/HCO3- both in
Na+/H+ exchanger
H+ ATPase
Na+/K+ exchanger removes Na+
K+ leak channel
What will the saliva be like if the flow rate is higher?
More HCO3-, more Cl-
- Isotonic
What will the saliva be like if the flow rate is lower?
Less HCO3-, less Cl-
- Hypotonic
