Physiology I Block II Flashcards
Part of saliva that begins initial digestion of carbohydrates
Alpha- amylase
Part of saliva that begins initial digestion of lipids
Lingual lipase
Part of saliva that provides lubrication
Mucin glycoproteins
Enzyme in saliva that acts on kininogen to release bradykinin – vasodilator which accounts
for high salivary blood flow during increased salivary activity
Kallikrein
Vitamin B12 binding protein in saliva whos purpose is to protect the transit of this vitamin
Haptocorrin (R protein)
Cells (present in the acini and line the
intercalated ducts) which eject saliva into mouth when stimulated
by neural input
Myoepithelial cells
Cells modify initial isotonic saliva to produce
final hypotonic saliva by altering electrolyte concentrations
Ductal cells
Cells have zymogen granules that contain
amylase
Serous acinar cells
Cells secrete mucin glycoproteins
Mucus acinar cells
Striated duct epithelium is relatively impermeable to
___ but avidly transports ___.
Water, salts
In the salivary striated ducts, the removal of NaCl exceeds the addition of KHCO3,
rendering the final secretion ____, but alkaline.
Hypotonic
At ___ flow rates, the final saliva is most similar to plams
High
At low slow rates (fasting), the final saliva is most ___ to plasm
Dissimilar
Parasympathetic fibers from the glossopharyngeal and facial nerves are dominant in activating ______ receptors to increase IP3/Ca2+ in blood vessels of salivary glands
Cholinergic muscarinic
Sympathetic stimulation in the salivary glands can cause increase in ____ via (typically) beta adrenergic receptors
cAMP
What type of saliva does sympathetic stimulation result in?
Mucous
Bradykinin, produced from kallikrein, results in ____ of blood vessels
Dilation
PNS can also increase blood flow to the salivary glands by directly releasing:
Vasoactive Intestinal Peptide (VIP)
What are the four major components of gastric juice?
HCl
Pepsinogen
Intrinsic Factor
Mucus
The antrum of the stomach secretes what two hormones?
Gastrin and somatostatin
Parietal cells secrete what? (2)
HCl and IF
Chief cells secrete what?
Pepsinogen
Parietal cells contain which important digestion-related pump?
H-K-ATPase
Which drug can block the H-K-ATPase?
PPIs (Omeprazole)
Gastric parietal cells secrete H+ in response to? (3)
ACh
Gastrin
Histamine
ACh is released from vagus nerves and binds to ___ receptors on parietal cells, activating PLC and liberating DAG and IP3 which lead to H+ secretion
M3
Name a muscarinic receptor antagonist
Atropine
Histamine is released from ____ cells in the gastric mucosa and binds to ___ receptors on parietal cells, leading to H+ secretion via adenylate cyclase/cAMP.
Enterochromaffin-like cells (ECL cells), H2
Name an H2 receptor antagonist
Cimetidine
____ gastrin is secreted in response to a meal, while ___ gastrin is secreted between meals/
Little/G17, Big/G34
The three jobs of gastrin are:
1) Promote H+ secretion by parietal cells
2) Promote growth of mucosa
3) Inhibit gastric emptying
What is the term for the ability of two stimuli to produce
a combined response that is greater than the sum of the individual responses?
Potentiation
30% of stimulated HCl is secreted in the ____ phase, while 60% is secreted in the ___ phase. 10% is in the intestinal phase.
Cephalic, gastric
What enzyme released from D cells in the stomach and duodenum, inhibits
parietal H+
secretion?
Somatostatin
____ antagonize
histamine-stimulated acid secretion by
the engaging Gi protein and inhibiting adenylyl
cyclase activity
Prostoglandins
____ is often the
result of an autoimmune disease
that causes degeneration of the
parietal cell.
Pernicious anemia
Due to large body stores of B12, prolonged (3-5 yr) deficiency of IF secretion (or lack of dietary intake) is needed to cause \_\_\_\_\_ because of defective red blood cell production.
Pernicious anemia
With a gastric ulcer, there is a/an ____ in gastrin levels.
Increase
With a duodenal ulcer, there is a/an ____ in gastrin levels.
Decrease
In this disease, gastrin is secreted by a pancreatic tumor, and there is increased parietal cell mass (and therefore increased H+) due to increased gastrin levels.
Zollinger-Ellison Syndrome
