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54 Cards in this Set
- Front
- Back
- 3rd side (hint)
t/f the esophagus has 5 types of muscles
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no, only has 2
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what organs have two types of muscles
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-esophagus
-stomach -intestines |
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what type of muscles do esophagus, stomach and intestines have
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they all have 2 types
1) Circular muscles 2) Longitudinal muscles |
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what is peristaltic reflex/ response
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The process of moving content forward by contraction/relaxation of circular and longitudinal muscles.
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t/f the peristaltic reflex/response is unidirectional?
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false. only moves one direction which is down. goes frm mouth to stomach
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what are the layers in order of the enteric ns
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1) longitudinal
2) myenteric plexus 3) circular muscle 4) submucosal plexus |
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where in the enteric ns does it hold its nerves
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myenteric plexus
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what is the submucosal plexus involved in
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secretion
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sympathetic fibers are=
parasymp are= |
symp= adrenergic
parasymp= cholinergic fibers |
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fxn of the enteric nervous system-2
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1) control of muscle contractions promoted by enteric interneurons and motor neurons that release : acetylcholine, serotonin and sub P
2) Control of muscle relaxation is promoted by enteric motor neurons that release: Vasoactive intestinal peptide (VIP) Nitric Oxide (NO) ATP Dopamine (binding to DA receptors) |
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what do enteric interneurons and motor neurons release to control the muscle contractions of the enteric ns (3)
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-acetylcholine
-serotonin - subs P |
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acetylcholine binds to ?
serotonin binds to? sub P binds to? |
Acetylcholine (binding to M3 receptors)
Serotonin (binding to 5HT-3 and 5HT-4 receptors) Substance P (binding to neurokinin receptors |
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what do enteric motor neurons release to control muscle relaxation? (4)
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Vasoactive intestinal peptide (VIP)
Nitric Oxide (NO) ATP Dopamine (binding to DA receptors) |
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t/f
it is easy to have drugs that target control of muscle relaxation by the enteric nervous system |
false. not that many drugs the relax, only dopamine does
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what are the diseases related to gi motility?
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-achalasia
-gastroparesis |
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what is achalasia
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-An esophageal motility disorder.
-Smooth muscle layer of esophagus looses peristalsis and lower esophageal sphincter does not properly relax in response to swallowing. Patient has difficulty swallowing and regurgitates food. |
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what is gastroparesis?
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delayed gastric emptying
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types of drugs that promote gi motility (4)
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- cholinergic drugs
- dopaminergic drugs - serotonergic drugs - macrolide antibiotics |
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name the cholinergic drugs
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-bethanecol
- neostigmine |
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explain the mech of cholinergic drugs
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- agonists for m3 receptors
- can increases gastric motility, but increase in motility is very limited |
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bethanecol
-type - moa -use ? past use? -adr? |
type: cholinergic drugs
moa: muscarinic agonist-m3 use: urinary retention. past use: gerd - rare use: for gi motility due to non synchronous contraction of gastric muscles and systemic adverse effects -adr? systemic adverse effects |
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neostigmine
type? moa? use? |
type: cholingergic drug
moa: reversible acetylcholine esterase inhibitor. enhances gi motility thus reduce emptying time use? treatment of pseudo-obstruction paralytic ileus via iv admin route |
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name the dopaminergic drugs-2
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-metoclopramide
-domperidone - |
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name the serotonergic drugs
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-metoclopramide
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name dopaminergic/serotonergic drugs
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- metoclopramide
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metoclopramide
type? moa? use? se? |
type: dopaminergic/serotonergic
moa: mixed mehanism of action -Serotonin 5HT-3 antagonist, 5HT-4 agonist, and non-specific DA receptor antagonist. use: Primarily used for upper GI motility problems. Increases esophageal peristaltic amplitude se: -cns effects in elderly: restlessness, drowsiness, insomnia, anxiety, agitation, extrapyramidal se (PK, tardive dyskinesia) -galactorrhea (prolactin inc) -menstrual disorders (prolactin inc) Increases lower esophageal sphincter pressure Enhances gastric emptyping. |
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what receptors does metoclopramide act as an antagonist or agonist for
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- Serotonin 5HT-3 antagonist, 5HT-4 agonist, and non-specific DA receptor antagonist.
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how does metoclopramide reduce gi motility problems (3)
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Increases esophageal peristaltic amplitude
Increases lower esophageal sphincter pressure Enhances gastric emptyping. |
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what se does metoclpramide have-6
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-has cns se
-CNS effects seen in about 20% of patients, particularly in elderly patients. Restlessness drowsiness insomnia anxiety agitation Extrapyramidal side effects (Parkinsonian symptoms, tardive dyskinesia, etc…) |
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doperidone
type? moa? se? |
type: dopaminergic drug
moa: dopamine d2 receptor antagonist. use -Has same clinical effects as Metoclopramide se -Does not penetrate through BBB very well. Thus much milder CNS side effects. -However, it could cause cardiovascular problems (arrhythmia, cardiac arrest). |
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name macrolide antibiotics-4
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-erythromycin
-clarithromycin -azithromycin -leandomycin |
cale
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macrolide antibiotics
moa |
-mimic the actions of the peptide hormone motilin
- motilin is a potent contractile agent of hte upper gi tract and si - macrolide antibiotics work like motilin to promote gi motility |
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what is motilin
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-peptide hormone
-potent contractile agent of the upper GI tract and si - released from enterchromaffin and m cells in the gi tract -promotes gi motility |
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what is constipation
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-difficulty defecating due to hard feces
- having infrequent bowel movements ( less than 3 x a week) -Difficulty defecating, straining for at least 25% of the time. -Sensation of hard stool -Sensation of incomplete bowel excretion |
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bristol stool chart
-type 1 and 2 indicate -type 3 and 4 indicate - type 5,6, 7 indicate -type of stool depends on? |
1 &2= constipation
3&4= ideal stool 5,6,7= diarrhea or cholera type depends on the amt of time it spends in the colon |
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t/f
most people need laxatives for the treatment of intermittent constipation |
- false. most people don't need laxatives
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instead of using laxatives people should -3
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- have a high fiber diet
- drink adequate amount of liquids - non caf -excercise regularly |
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what are the types of laxatives-4
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-bulking agents
-stool surfactants (softeners) - osmotic laxatives - irritant of stimulant laxatives |
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egs of bulking agents
types and egs of each type |
1) natural plant products
-psyllium (metamucil) - methylcellulose (citrucil) 2) synthetic fibers -polycarbophil (equalactin) |
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how do bulking laxatives work
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-Hydrophilic colloids that are made of indigestible parts of fruits, vegitables, & seeds.
-Absorb water, forming a bulky gel that distends(swells) the colon and promotes peristalisis |
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egs of stool surfactants-3
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-docusate (colace)
- glycerin suppository - mineral oil |
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moa of stool surfactants
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- permit water and lipids to penetrate and soften stool material
- may be administered orally or rectally |
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egs of osmotic laxatives
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Magnesium oxide (milk of magnesia)
Magnesium citrate (Citroma) Sodium Phosphate (Visicol)- commonly used for colonoscopies |
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which of the osmotic laxatives is used for colonoscopies
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- sodium phosphate( visicol)
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osmotic laxatives
moa? made of? use? adr? |
moa= osmotic laxatives are soluble but nonabsorbable compounds that increase fecal liquidity
use= for the treatment of acute constipation or prevention of chronic constipation adr: w/ renal disease or in restricted salt diets should not use these products made of= non absorbably sugars and salts |
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egs of irritant/stimulat laxatives
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-bisacodyl
-anthraquinone derivatives -senna -cascara -aloes -castor oil |
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moa os irritant or stimulant laxatives
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Induce GI motility by directly acting on enterinc neurons, Gi smooth muscles, but via mechanisms not well understood.
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bisacodyl is what type of drug
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-irritant/stimulant laxative
-potent colonic stimulant |
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egs of anthraquinone derivatives
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-cascara
- senna -aloes |
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moa of anthraquinone derivatives
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- contain emodin alkaloids (resin) that are poorly absorbed
- After hydrolysis in colon, it causes an increase in peristalsis. |
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moa of castor oil
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-Active ingredient is ricinoleic acid
- A very potent laxative - As little as 4ml can produce laxative effects in 1-3 hours. |
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what types of laxatives soften the feces
(1-3 days) |
- bulk forming laxatives
- surfactant laxatives |
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what types of laxatives make soft of semifluid stool (6-8 hrs)
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-stimulant laxatives
-anthraquinone derivatives |
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what types of laxatives make watery evacuation in 1-3 hrs
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osmotic laxatives
castor oil |
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