GI 2

Question 1

define gastroparesis

Answer 1

delayed gastric emptying (even though there is no blockage in stomach/intestines)

Question 2

define gastritis and 4 causes

Answer 2

inflammation of the gastric mucosa

acute NSAID use, chemotherapy agents, high dosage of drugs, individuals who use OTC/unscheduled antacids/antihistimanes

Question 3

How can long-term damage to GI mucosa lead to cancer?

Answer 3

fast regeneration of GI cells can cause increased risk of cell morphing

Question 4

2 examples of congenital malformations relating to the trachea and esophagus; provide 3 S&S and when it is diagnosed

Answer 4

tracheoesophageal fistula - esophagus and trachea do not separate and are connected
esophageal atresia - esophagus fails to reach the stomach

S&S: vomiting, lack of stool, choking

diagnosed during first minutes/hours of life, require surgery

Question 5

describe the dimensions of the small intestines;name the 3 parts of the small intestine; determine their functions

Answer 5

20 feet long + 1 inch in diameter

duodenum + jejunum (upper GI) = digestions + absorption, chyme enters duodenum and bile secretion facilitated by CKK, triggering pancreatic juice secretions
ileum (lower GI)

Question 6

how much bile + pancreatic juices is secreted into the duodenum; what are they adjuncts to?

Answer 6

~1L of bile + pancreatic juices/day into duodenum; they are adjuncts to lipase, amylase, and trypsin

Question 7

describe the metabolism of proteins + how it is absorbed into the bloodstream

Answer 7

proteins first digested in the stomach via pepsin; protein also broken down into amino acids by pancreatic juice enzymes; transferred into bloodstream via active transport + facilitated diffusion

Question 8

describe the metabolism of carbohydrates and how it is absorbed into the bloodstream

Answer 8

carbohydrates are broken down into monosaccharides (simple sugars); digested in saliva via amylase, brush border enzymes (maltose + lactase); absorbed into the bloodstream as glucose/galactose + fructose via facilitated diffusion

Question 9

explain what occurs when sugars aren’t properly broken down into simple sugars

Answer 9

when sugars aren’t broken down into simple sugars, they can cause osmotic movement of water into the intestines which can cause diarrhea.

Question 10

explain lactose intolerance

Answer 10

the lack of lactase decreases the amount of sugars are broken down, the sugars can start to ferment and cause cramping + bloating, leading to increased volume of intestines

Question 11

describe the metabolism of fats and how it is absorbed into the bloodstream

Answer 11

digestion starts at the mouth via lingual lipase, it is emulsified via bile and pancreatic juices and is broken down into fatty acids; fatty acids enter the lymphatic system first as triglycerides before entering systemic circulation

Question 12

describe the dimensions of the large intestine and list the 4 major parts

Answer 12

LI = 5 feet long and 3 inches in diameter

ascending, transverse, descending, and sigmoid colon

Question 13

what is the major functions of the large intestines?

Answer 13

primary remover of waste products, water reabsorption via simple columnar cells, and host flora essential for vitamin B12 + K synthesis

Question 14

what can enemas/cleansing do to the flora in the large intestines?

Answer 14

it can strip them disbalance the flora within the large intestines

Question 15

name the sections of the nervous system that affect GI motility

Answer 15

ANS: sympathetic (stops GI function), parasympathetic (triggers GI function)
Enteric Nervous System

Question 16

name 3 triggers for the enteric nervous system

Answer 16

mechanoreceptors signal GI to stretch to begin digestion

chemoreceptors signals GI when there is food present/osmolality + pH changes

ANS

Question 17

describe Hirschsprung disease and how it can be treated

Answer 17

a congenital defect in which there is an abscence of parasympathetic ganglia in the wall of the LI; areas without these ganglia cannot undergo peristalsis and can cause fecal impaction.

It can be treated via pull-through surgical procedure in which affected areas are excised

Question 18

describe 2 chronic inflammatory diseases that affect the GI; name 3 common S&S; and treatments recommended

Answer 18

Crohn disease: can affect anywhere from mouth to LI, patchy inflammation, affects thickness of bowel (cobblestone)
Ulcerative colitis: only affects LI, continuous inflammation, affects layers + submucosal layers

S&S: anorexia, diarrhea, nausea
long-term treatment is recommended d/t chronicity

Question 19

describe the pathophysiology of celiac disease

Answer 19

celiac disease aka gluten sensitive enteropathy occurs when overt T-cell (memory) mediated immune response to alpha-glial in (gluten component), leading to inflammation and causes the lose of villi

Question 20

describe the signs and symptoms of celiac disease; complications; how it is diagnosed and treated

Answer 20

S&S: malnutrition, anorexia, bloating, diarrhea; complications include malnutrition; it is diagnosed via serology and endoscopic biopsy; treatment is avoidance of gluten

Question 21

describe C. difficile and its pathophysiology; S&S of infection, Diagnostic tools; Tx during and after antibiotics

Answer 21

C. difficile is a gram positive bacterium; it creates a toxin that destroy mucosal lining of intestines
S&S = severe diarrhea, melena, and systemic presentations
Diagnosed via stool culture + empiric tx needed
treatment drugs = Flagyl, PO (first option), then Vancomycin
treatment options after antibiotics = fecal microbiota transplant (FMT) + probiotics (BioK+)

Question 22

which individuals are @ risk of C. difficile infection?

Answer 22

long-term antibiotic treatment patients as it allow for C. difficile already in the body to grow.

Question 23

describe E. coli and its pathophysiology; S&S and severe complication; treatment used

Answer 23

Gram negative bacteria that produces toxins, often contaminates foods, undercooked meats, unwashed vegetables + hands
S&S include diarrhea, pain, fever
Severe complication HUS (hemolytic uremic syndrome) which is life-threatening, causing renal failure (dialysis recommended)
Treatment is supportive and aggressive and involves hematology + rehydration

Question 24

which E. coli strain causes the most severe symptoms?

Answer 24

O157-H7 strain aka Shiga toxin strain that destroys endothelial cells, platelets + RBCs

Question 25

describe the pathophysiology of hemolytic uremic syndrome and what uremia is; S&S and treatment

Answer 25

HUS is caused by the O157-H7 “Shiga” strain that destroys endothelial cells, platelets + RBCs which causes uremia. Uremia: the buildup of nitrogenous wastes in blood d/t renal dysfunction S&S: bloody diarrhea, jaundice, anemia, easy bruising, rashes Treated vis supportive tx = fluids, blood transfusion, dialysis

Question 26

describe diarrhea and its causes; acute vs chronic; its complications

Answer 26

Diarrhea is a symptom that is caused by increased frequency + fluidity of loose/unformed stool Acute onset lasts <2 weeks, chronic lasts >4 weeks Complications include electrolyte imbalance d/t increased nutrients in stool, dehydration, malabsorption

Question 27

explain why rehydration is important: list ways people are hydrated in the hospital, at home, and when it is not available

Answer 27

rehydration is important in maintains homeostasis in hospital: Isotonic IV solution (normal saline = H2O + sodium) used and serum electrolytes are checked at home: Gastrolyte and Pedialyte (used for peds) used. If vomiting, need to got o hospital to use IV when not available anywhere: can be made using 1L H2O, 80ml glucose, 7ml NaCl

Question 28

describe how antidiarrheal medications work and its schedule; also describe possible side effects

Answer 28

antidiarrheals are opioid-based and have high agonism for mu2 receptors in the GI ENS, decreasing peristalsis in the process low dose antidiarrheals are OTC while higher dose antidiarrheals require a prescription high dosage can lead to CNS depression and addiction

Question 29

describe a characteristic of antidiarrheal medications and how each component of the drug works; name 2 drugs

Answer 29

drugs are always combination medications based on one opioid and one atropine (CNS stimulant); atropine is an antimuscarininc (anticholinergic) agent that stimulates sympathetic/blocks parasympathetic to decrease GI movement; atropine counteracts the opioid Drugs: Lomotil (diphenoxylate atropine) Imodium (loperamide HCl)

Question 30

describe constipation and 2 possible causes

Answer 30

constipation is a symptom that is characterized by infrequent, incomplete/difficult passage of stool it can be caused by inadequate fluid/fiber intake (dietary) = too much fiber + too low fluid = bad because fiber becomes very dense = more blockage also caused by alterations in peristalsis/intestinal innervation impacting colonic motor function d/t inactivity, surgery, drugs, pain, Hirschsprung disease, and altered bowel movement d/t emotions like embarrassment

Question 31

explain how bulk-forming laxatives work; name a drug, its RoA, and schedule and its best use scenario

Answer 31

bulk-form laxatives work by pulling water into stool and adding bulk to stool (usually fibre) Psyllium (Metamucil) contains fibre that increases bulk + pulls in water Most PO, some PR; no systemic absorption and most are unscheduled best used in prophylaxis (1-2 days); water intake is needed and used in long-term scenarios

Question 31

name the 5 types of laxative and determine which pulls water into the stool

Answer 31

bulk-forming laxatives, softeners, saline & osmotics, stimulants, and miscellaneous bulk-forming laxative, softeners, and saline & osmotics used water

Question 32

explain how softeners work, name of a drug, and best case scenario

Answer 32

softeners work by pulling water and fat into the stool, making it slippery and easier to pass; good renal function for excretion docusate sodium (Colace) used for prophylaxis best used after an MI and after surgery

Question 33

describe how saline and osmotics work; 3 drugs and their main usage, best use scenarios

Answer 33

saline and osmotics work by pulling water into stool Milk of Magnesia is systemically absorbed, check renal function during usage) Lactulose is not systemically absorbed; can cause intestinal cramping d/t synthetic sugar, avoid in patients who are lactose intolerant GoLytely is a powder pre-procedural is best, it is potent and acts fast (20mins, 1-3 hours)

Question 34

explain how stimulant laxatives, its absorption, 3 drugs, side effects, and best case scenario

Answer 34

stimulants works as irritants and increase peristalsis by binding to EP3 receptors in smooth muscle wall to increase contraction it is not absorbed systemically Drugs: Dulcolax, Senna (Eclax, Senokot), Castor Oil Side effects include N&V and cramping Do not use for long-term constipation or pre-surgery, use for individuals with fluid restrictions since H2O not needed to propel stool

Question 35

explain how miscellaneous type laxatives work and provide an example of when it is used

Answer 35

miscellaneous type laxatives are sued as adjunct treatments with constipation cathartics aka enemas are used before procedures and are used to expand the bowel for fast evacuation, PR administration using Sims position and water + electrolyte combination

Question 36

describe bloating and how it is assessed; name 2 drugs used to treat bloating

Answer 36

bloating is a symptom in which gas builds up within the intestines; it is assessed using percussion of the abdomen. simethicone (Gas X) is a surfactant that breaks the surface tension of bubbles and dissolves them, they are not systematically absorbed alpha-d-galactosidase (Beano) is a carbohydrate enzyme that increases digestion and formation of simple sugars

Question 37

describe the physiology of vomiting

Answer 37

medulla centers contain the vomiting/emetic center (neuronal network) that when it receives stimuli from CTZ (chemoreceptor trigger zone), organs or body regions, it will trigger GI + diaphragm contractions which results in emesis.

Question 38

what characteristics allow the CTZ to receive stimuli and cause triggers?

Answer 38

the chemoreceptor trigger zone lies outside of the BBB, being exposed to blood contents and the CSF which helps sense triggers

Question 39

How do we treat drugs according to the emetic pathway?

Answer 39

since receptors are stimulus specific, depending on the stimulus, we intercept the receptors with drugs to cut off messages to the emetic center

Question 40

if motion/position is the stimulus, determine the area where it will be detected and which receptors are needed to be intercepted to avoid the emetic center

Answer 40

area detected = vestibules in the ear, receptors needed to be intercepted = muscarinic (acetylcholine) + histamine

Question 41

if drugs or metabolic activity is the stimulus, determine the area where it will be detected and which receptors are needed to be intercepted to avoid the emetic center

Answer 41

area detected = CTZ, receptors needed to be intercepted - dopamine + serotonin

Question 42

if visceral activity is the stimulus, determine the area where it will be detected and which receptors are needed to be intercepted to avoid the emetic center

Answer 42

area detected = organs, receptors needed to be intercepted = dopamine + serotonin

Question 43

if something non-specific (aka stress, emotions) is the stimulus, determine the area where it will be detected and which receptors are needed to be intercepted to avoid the emetic center

Answer 43

area detected = CNS, receptors needed to be intercepted = cannabinoid receptors

Question 44

if increased ICP is the stimulus, determine the area where it will be detected and which receptors are needed to be intercepted to avoid the emetic center

Answer 44

are detected = cerebral cortex; receptors needed to be intercepted = histamine

Question 45

when treating N&V what do we target? what else can do to treat N&V?

Answer 45

we target the most appropriate receptors, we can also treat the underlying cause; for example, pain and food poisoning

Question 46

what can be the effect of profuse vomiting as a treatment?

Answer 46

dehydration and electrolyte imbalances; important to correct both

Question 47

what receptor needs to be antagonized when the stimulus is motion induced, morning sickness, or anticipatory?

Answer 47

H1 receptors which excite vestibules, therefore need antihistamines

Question 48

name 3 H1 antagonist drugs that is used to antagonize vestibular excitation receptors; determine their components and best use scenarios

Answer 48

dimenhydrinate (Gravol) = diphenhydramine + chlorotheophyline (stimulant like caffeine); used for motion sickness Meclizine (Dramimine) Dicletin = doxylamine (low dose antihistamine) + pyridoxine hydrochloride (vitamin B6); only drug approved for morning sickness and safe for pregnancy; believed to be placebo

Question 49

what is ginger gravol used for? determine its pharmacotherapeutic class and its effects if overdosed

Answer 49

ginger gravol is used for increasing intestinal emptying by increasing peristalsis it is an NHP safe to use in moderate doses, unsafe if overdose and can cause bleeding + CNS depression and interferes with insulin secretion

Question 50

describe the action of antimuscarinic anticholinergics and name a drug and its possible RoAs

Answer 50

antimuscarinic anthicholinergics reduce vestibular excitation causing a sedative effect, it also has some affinity to H1 receptors scopolamine (Hyoscine); transdermal patch, IV, PO, not available for canadian market

Question 51

this form of antagonism is used for treating drug-induced and chemotherapy treatment/visceral pain. explain the pathophysiology + a drug example

Answer 51

serotonin (5HT3) antagonists is used to block serotonin from communicating with the CTZ for N&V Drug: Ondansetron (Zofran); prescription only (very potent); PO, IV

Question 52

what does D2 receptor communicate and determine how it is blocked; name a drug class and 2 drugs. Determine prescription, RoA and side effects

Answer 52

D2 receptors communicate GI pain; it is blocked using phenothiazines which stimulate GI motility Metoclopramide (Maxeran used in small doses to enhance NJ tube placement by increasing GI motility; Reglan) Prochlorperazine (Stemetil) prescription only, PO, IV, SC; s/e = sedation

Question 53

CB1 & 2 agonism is used to block what kind of stimulus? determine the active ingredients and what each of them does

Answer 53

CB1 & 2 agonism is used to block chemotherapy, chronic disease, challenging cases cannabinoids’ active ingredients: THC (terahydrocannabinol) binds to CB1= if centrally binding, inhibits 5HT3 and decrease emesis; CBD (cannabidiol) binds to CB2

Question 54

name 3 cannabinoid drugs

Answer 54

Dronabinol (Marinol); Cesamet/Nabilone; cannabis

Question 55

name the 3 other neurotransmitters that can be affected by CB1 & 2 agonism and determine the risk and benefit for 2 of them

Answer 55

serotonin = decreased serotonin secretion within GI = calming of GI GABA Dopamine serotonin + GABA = risk of addiction does not outweigh benefit of interfering with N&V