GI Tract Flashcards
Alimentary canal
Long continuous hollow tube
Extends from mouth to anus
Accessory Digestive organs
salivary glands
liver
gallbladder
pancreas
Function of GI tract
transport food
provide enzymes
provide surface area for chemical digestion
provide surface area for absorption
Control of GI system
nerve plexus a. maintains basic electrical rhythm b. responds to local stimuli to increase or decrease activity influenced by the ANS a. sympathetic reduces parasympathetic increases
digestive enzymes of St
gastrin in anticipation of food
chief cells secrete pepsinogen
parietal cells secrete HCl and intrinsic factors
Gastrin function
causes St muscle to contract
causes release of HCl and Pepsinogen
Fibber decreases the concentration of acid in St.
Pepsinogen function
breaks down protein
Instrinsic factor function
essential for Vit B 12 absorption
Parietal Cell function
protect body from ingested microbes
aid in chemical digestion
secrete HCl and intrinsic factor
HCO3 and thick mucous layer protect the stomach lining from acid
Liver/Pancreas enzymes
Trypsin - protein
Amylase - sugar
Lipase - fat
Bile
breaks down fat
Endocrine hormones involved
insulin
glucagon
somatostatin
Where is portal system?
Liver
what is basic movement
peristalsis
how many muscle layers does St have
3 - produces churning action
Motility process of Si
segmentation
Motility process of Li
mass movement
Gastroenteric reflex
stimulates St by stretching causing an increase in Si activity
Gastrocolic reflex
stimulates the St causing increase colon activity
Duodenal - colic reflex
stimulates colon activity and mass movement by presence of food or stretch in duodenum
intestinal intestinal reflex
irritation in the Si in one area which can cause paralytic ileus
swallow reflex
stimulated by pressure of receptors in back of throat by a food bolus
vomiting reflex center
in medulla - 2 centers
emetic zone
CTZ zone (Chemoreceptor trigger zone)
How does stimulation of the CTZ zone induce vomiting
tactile stimulation of back of throat
excess St distention
increased intracranial pressure by direct stimulation
stimulation of vestibular receptors in inner ear
stimulation of stretch receptors in uterus and bladder
intense pain fiber stimulation
direct stimulation of various chemicals
head injury causes what physiological changes
increasing intracranial pressure
stimulation of vestibular receptors can cause what physiology response
motion sickness, nausea, vomiting
physical response before vomiting
increased saliva, mucus production in upper GI, sweating, HR, deeper breathing, nausea
decreased gastric acid production
TPN and ingredients
total parenteral nutrition
hypertonic solution
contains AA, lipid emulsions, carbs (dextrose), electrolytes, vitamins, minerals
vitamins
organic substances needed to promote growth and maintain health
indications for vitamins
alcoholics
pregnancy, breast feeding
chronic Kd/Lv disease
therapy with certain meds that affect vitamin metabolism
water soluble vitamins
B & C
easily dissolved and excreted in urine - required daily
thiamine B1
promotes muscle and nervous system
found in enriched whole grains
Riboflavin B2
RBC production and body growth
found in milk, yeast, liver
Niacin B3
helps form coenzymes
found in meat
Pyroxidine B6
RBC synthesis, CHO and lipid metabolism, neurotransmitter synthesis
found in grains, egg yolk
Folic Acid B9
DNA snthesis, homocysteine metabolism, neurotransmitter formation, helps complete formation of spine
green leafy
B12
found in meat, seafood, eggs
Vit C
found in citrus fruits
deficiency leads to scurvy
Lipid soluble vitamins
ADEK can be toxic in excess amounts must be ingested with other lipids stored in Liver and fat tissue absorbed in Si
Vit A
eye health, skin, skeletal health
excess leads to orange skin, loss of hair, peeling skin
Vit D
absorption of Ca
Vit E
antioxidant
Vit K
clotting factors
Minerals
inorganic substances that are needed to maintain body metabolism
ingested
drugs that affect mineral metabolism
thiazides or loop diuretics - lose K
corticosteroids, oral contraceptives - retain Na; lowers plasma zinc, increases copper
oral hypoglycemics, lithium carbonate - impairs uptake of iodine by thyroid
what is a hemoglobin molecule composed of
4 heme molecules
role of sodium
fluid and electrolyte balance
maintenance of extracellular fluid balance
acid/base balance
muscle contraction - enters the fast channels during depolarization - nerve transmission
K role
fluid, electrolyte balance, cell integrity, maintain Ht beat (Ca/Na in, K out)
found in banana, potato
Cl role
follows Na
part of HCl
acid/base, eletrolyte balance
Ca
for nerve conduction, musc contraction, hemostasis,
prep: Ca Carbonate, citrate, gluconate, lactate
hypocalcemia
PO
phosphorus
bone formation
part of ATP
Mg
nueromusc function - uterine contractions
salts for laxatives
Trace minerals
only less than 20 mg required Fe iodine fluorine zinc
Fe excess
hemochromatosis
fe deficiency
anemia
Iodine
for thyroid hormone
from iodized salt
deficiency - goiter
excess - suppresses thyroid function temporarily
Lugol’s solution
iodine mixture
administered prior to thyroidectomy
sodium iodine
for acute thyroid crisis
fluorine
excess - toxic
for bones and teeth
zinc
helps with immunity wound healing male fertility bone formation excess destroys sense of taste and smell
peptic ulcer disease risk
family hx type O smoking alcohol caffeine meds - corticosteroids, aspirin, nsaids stress h pylori
types of ulcer
duodenal
gastric
duodenal ulcer
burn upper abd
1-3 hrs after eating
disappears after ingesting
bleeding
gastric ulcer
more serious less commmon requires longer tx relieved by food, but continues after meal anorexia, vomit, weight loss
drugs that affect GI secretions
Histamine 2 antagonist protein pump inhibitor antacid antipeptic agent prostaglandin digestive enzymes
Cimetidine (Tagamet)
H2 receptor antagonist suppresses volume and acidity of ST acid treats GERD 800 mg @ bedtime or QID weaker than proton pump inhibitors
c/i of Tagamet
concurrent antacid therapy - NO!
breast feeding
Kd Lv dysfunciton
elderly
interactions of tagamet
antacids inhibit absorption
smoking increases HCL secretion
A/R of Tagamet
h/a, dizziness, confusion, decrease libido.
watch for abd pain, FRANK AND OCCULT BLEEDING, avoid irritants
Other H2 receptor drugs
Pepcid
Zantac
Omeprazole (Prilosec)
Proton Pump Inhibitor for PUD and GERD blocks enzymes that secrete HCl works better and longer than H2 receptors for erosive esophagitis associated with C Diff & Hip Fx can administer with antacid
A/R of Prilosec
h/a diarrhea abd pain n/v dizziness rash constipation dry mouth flatulence
Prilosec interactions
interfere with metabolism of valium, dilantin, coumadin.
interfere with absorption of drugs that need gastric pH
other protein pump inhibitors
Prevacid
Protonix
Sodium Bicarbonate (Bell/Ans)
antacid
was for GERD and PUD
alkaline, inorganic compounds of Al, Mg, Ca
neutralizes st acid
Al compounds may interfere with phosphate metabolism and cause constipation
which compounds cause constipation
Al
Ca
which compounds may cause diarrhea
Mg
Common antacids
Mylanta
Maalox
Amphojel
nursing consideration for antacids
monitor for systemic alkalosis
administer 1-2 hours before other oral meds
assess for OTC, Rx, KD insufficiency
Antibiotic therapy used with antacids
for H Pylori Amoxicillin (Amoxil) Clarithromycin (Biaxin) Metronidazole (Flagyl) - antifungal Tetracycline (Achromycin)
Sucalfate (carafate)
Antipeptic agent
coats ulcer crater
for short term and prevention
cautions, with antipeptics
c/i hypersensitivity caution - breast feeding, chronic renal failure a/r -constipation interaction - binds with other drugs NOT WITH OTHER AL BASED PRODUCTS frank/occult bleeding
Misoprostol (Cytolec)
Prostaglandin
inhibits HCl secretion and increases HCO3 and Mucus
prevents NSAID induced gastric ulcer
treats duodenal ulcer
c/i of prostaglandin
cautions, A/R
Pregnancy
lactation
n/v, diarr, abd pain, flatulence, dyspepsia, constip.
miscarriage, excess bleeding, spotting, cramps, hypermenorrhea, dysmenorrhea.
Pancrelipase (Pancrease)
Digestive Enzyme
need artificial saliva with elecrolytes
help digest and absorb fat, protein, carbs
replacement therapy
digestive enzyme cautions and a/r
c/i - enzymes -> gastric irritation
pregnancy and lactation
contact dermatitis, N, abd cramps, diarr, skin irritation
saliva allergy
cautions: CHF, hypertension, Kd fail
a/r - complications from abn electrolytes, increased levels of Mg, Na, K
vomiting center
medulla
senses toxins and triggers reflex
n/v drug classes
phenothiazine - compazine antihistamines - benadryl cannabinoids - marinol glucocorticoids - decadron benzodiazepine - ativan serotonin receptor antagonists - zofran
Prochloroperazine (compazine)
phenothiazine - antiemetic
helps nausea
used for kids as suppository
Metoclopramide (Reglan)
NON Phenothiazine - antiemetic
improves emptying gastric area, for diabetic paralytic ileus
for n/v motion sickness, diabetic gastroparesis, tube feeding to promote emptying
NOT WITH DIGOXIN
ONdansetron - Zofran
serotonin 5-HT3 receptor blocker
blocks receptors assoc with n/v in CTZ
used for chemo and post op
c/i -preg/lact, myalgia, urin retent
C/I & A/R of antiemetic
GI obstruction angle closure glaucoma bone marrow depression Lv Ht dz watch for anticholinergic effects - hyptension, constip, blurred vision, dryness of eyes, mouth, rectal irritation, drowsy, photosens, urin retent.
Meclizine (Antivert)
ANtichol/antihistamine
block impulse to CTZ
for n/v, motion sickness
Aprepitant (Emend)
substance P neurokinin 1 receptor antagonist
in CNS block receptors assoc with n/v
combo with other agents - for chemo
encourage fluids!
a/r - anorexia, fatigue, constip, diarr, LV enzyme elevation, dehydration
Ipecac syrup
emetics
induce vomit
2003 warning - not recommended anymore
c/i semicomatose, unconscious - risk for aspiration
a/r - arryth, diarr, drowsy, cardiotoxicity
follow with 1-2 glasses of water
