GI Terminology and Anatomy Overview

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Questions and Answers

What is the primary mechanism of action for opioid-based antidiarrheals?

Decreased secretion of mucus

Increased intestinal motility

Decreased peristalsis via Mu2 receptor agonism (correct)

Inhibition of water absorption

Which of the following is a component of a homemade rehydration solution in 'no-mans-land'?

1.5 liters of water with electrolytes

1 liter of water, 80 mL of glucose, 7 mL of NaCl (correct)

200 mL of glucose

500 mL of saline

What symptom is associated with fecal impaction?

Frequent, loose stools

Complete bowel obstruction without prior symptoms

Increased frequency of bowel movements

Retention of hardened or putty-like stool (correct)

What is a common dietary cause of constipation?

Inadequate fluid or fiber intake Signup and view all the answers

Which type of laxative works by pulling water into the stool and adding bulk?

Bulk forming laxatives Signup and view all the answers

What is a potential consequence of overdosing on ginger as a medication?

CNS depression Signup and view all the answers

Which medication is primarily used as a transdermal patch for reducing vestibular excitation?

Scopolamine (Hyoscine) Signup and view all the answers

Which drug class includes medications that stimulate GI motility through D2 receptor antagonism?

Phenothiazines Signup and view all the answers

What is the main active ingredient in Dronabinol (Marinol)?

THC (tetrahydrocannabinol) Signup and view all the answers

Which of the following side effects is associated with medications that belong to the Phenothiazine class?

Sedation Signup and view all the answers

What is the primary function of the small intestine?

Absorption of nutrients Signup and view all the answers

Which part of the large intestine is NOT correctly matched with its function?

Sigmoid colon - absorption of nutrients Signup and view all the answers

Which term describes a loss of appetite?

Anorexia Signup and view all the answers

What role does the 'host flora' play in the gastrointestinal system?

Synthesis of Vitamins B and K Signup and view all the answers

Which disorder is characterized by an inability to properly innervate the intestinal muscles?

Hirschsprung disease Signup and view all the answers

What is the length of the small intestine?

20 feet Signup and view all the answers

Which blood test specifically checks for antibodies related to gastrointestinal issues?

Serology Signup and view all the answers

Which part of the large intestine is primarily involved in the initial absorption of water?

Ascending colon Signup and view all the answers

What is the primary immune response triggered by gluten in celiac disease?

T-cell mediated response Signup and view all the answers

Which of the following is NOT a common symptom of celiac disease?

Nausea Signup and view all the answers

What is the preferred treatment approach for managing celiac disease?

Avoidance of gluten Signup and view all the answers

What is a severe complication that can arise from an E-coli infection?

Hemolytic uremic syndrome Signup and view all the answers

What is the typical treatment option for an E-coli infection?

Supportive care Signup and view all the answers

Which of the following statements about diarrhea is accurate?

Diarrhea can result from the intake of gluten in celiac disease. Signup and view all the answers

What is a potential complication of untreated diarrhea?

Electrolyte imbalance Signup and view all the answers

Which of the following is a risk factor for E-coli infection?

Undercooked meat Signup and view all the answers

What is a primary treatment for abdominal discomfort caused by dietary ingestion?

Simethicone Signup and view all the answers

Which enzyme is specifically used to enhance the digestion of carbohydrates into simple sugars?

Alpha-d-galactosidase Signup and view all the answers

What is a characteristic of gastroparesis?

Delayed gastric emptying Signup and view all the answers

Which of the following mechanisms can trigger vomiting?

Stimulation of the medulla's vomiting center Signup and view all the answers

What is the potential side effect of medications that target nausea and vomiting?

CNS depression Signup and view all the answers

Which type of receptors are antagonized to treat motion-induced nausea?

H1 receptors Signup and view all the answers

What should be addressed when treating the effects of profuse vomiting?

Correct dehydration and electrolyte imbalances Signup and view all the answers

Which drug is a combination of diphenhydramine and chlorotheophylline, used for nausea?

Dimenhydrinate Signup and view all the answers

Study Notes

GI Terminology

Host flora: Intestinal bacteria, up to 500 species.
Colonization: The development of host flora in the intestines.
Anorexia: Loss of appetite.
Retching: Rhythmic movements of abdominal muscles, diaphragm, and chest wall.
Emesis: Vomiting, expulsion of GI contents.
Congenital: Present at birth.
Dysphagia: Difficulty swallowing.
Serology: Blood test, specifically antibody testing.
Biopsy: Tissue sample for patho-analysis.
Colonoscopy: Viewing of the lower GI tract.
Endoscopy: Viewing of the upper GI tract.

Upper GI: Congenital Malformations

TEF (TE fistula): Tracheoesophageal fistula, a connection between the trachea and esophagus.

Small Intestine

Length: 20 feet (6 meters)
Diameter: 1 inch
Parts: Duodenum, jejunum, ileum (longest).
Major Function: Absorption of nutrients.
Associated Organs: Pancreas, liver, gallbladder.

Large Intestine

Length: 5 feet (1.5 meters)
Diameter: 3 inches (7 cm)
Parts: Ascending colon, transverse colon, descending colon, sigmoid colon.
Major Functions: Reabsorption of water, vitamin B & K synthesis by host flora.

GI Innervation Review

Intestinal Motility: Affected by the nervous system:
- ANS: Sympathetic and parasympathetic nervous systems.
- Enteric Nervous System: Receives input from:
  - Mechanoreceptors: Detect GI stretch.
  - Chemoreceptors: Detect food presence, osmolality, and pH.

Innervation Issues

Hirschsprung Disease: A congenital condition where nerve cells are missing in the large intestine, impacting motility.

Inflammatory Disorders

Common Signs and Symptoms: Anorexia, diarrhea, nausea.
Celiac Disease:
- Gluten-sensitive enteropathy: Gluten triggers an immune response to alpha-gliadin, leading to inflammation and loss of villi in the small intestine.
- Signs and Symptoms: Anorexia, bloating, diarrhea, malnutrition.
- Complications: Malnutrition, weight loss, anemia.
- Diagnosis: Serology and biopsy.
- Treatment: Gluten-free diet.

Infectious Diseases

C-Dif:
- Gram-positive bacteria.
- Treatment options include antibiotics.
E-Coli:
- Gram-negative bacteria.
- Causes: Ingestion of E-coli, often from undercooked meat, contaminated vegetables, water, and unwashed hands.
- Signs and Symptoms: Diarrhea, pain, fever.
- Complications: Hemolytic uremic syndrome, a life-threatening condition caused by Shiga-toxin damaging endothelial cells, platelets, and red blood cells.
- Treatment: Supportive care.

Diarrhea

Symptom: Increased frequency and fluidity of loose or unformed stool.
Causes: Inflammation or infectious organisms.
Types: Acute (less than 4 weeks) and chronic (more than 4 weeks).
Complications: Electrolyte imbalance, dehydration, malabsorption.
Treatment: Rehydration, antidiarrheal medications.

Rehydration

Hospital: Isotonic IV solutions (e.g., Normal Saline) and serum electrolyte monitoring.
Home: Oral rehydration solutions (e.g., Gastrolyte, Pedialyte).

Antidiarrheal Medications

Opioid-Based:
- Mechanism of action: Mu2 receptor agonism in the GI's Enteric Nervous System, decreasing peristalsis.
- Examples: Lomotil (diphenoxylate atropine), Imodium (Loperamide HCl).
- Side Effects: Central nervous system depression, addiction.
Atropine: Antimuscarinic agent that blocks the parasympathetic system and stimulates the sympathetic nervous system.

Constipation

Symptom: Infrequent, incomplete, or difficult passage of stool.
Causes: Inadequate fluid or fiber intake, alterations in peristalsis or intestinal innervation, inactivity or bedrest, surgery, drugs, pain, and altered bowel routine.
Treatment: Laxatives (bulk forming, softeners, stimulant, osmotic, lubricant).

Bloating

Symptom: Gas.
Treatment: Gas X (simethicone) and Beano (alpha-d-galactosidase).

Gastroparesis

Slowed or stopped movement of food from the stomach to the small intestine without a blockage in the stomach or intestines.

Nausea and Vomiting

Defense System: A protective mechanism triggered by different stimuli.
Physiology: Vomiting center in the medulla receives stimuli from the chemoreceptor trigger zone (CTZ), organs, and other regions.
CTZ: Situated outside the blood-brain barrier, it is exposed to blood and cerebrospinal fluid contents.
Stimuli:
- Motion induced (motion sickness).
- Anticipatory nausea.
- Food poisoning.
- Pain.
- Medications.

Treatment of Nausea & Vomiting

Target specific receptors:
- Antihistamines (H1 antagonists).
- Antimuscarinic anticholinergics.
- Serotonin antagonists (5HT3 antagonists).
- Dopamine antagonists.
- Cannabinoids (CB1 and CB2 agonists).
Treatment of the underlying cause: Treat pain, food poisoning, etc.
Treatment of the effects of profuse vomiting: Rehydration and electrolyte correction.

Antihistamine Medications

Mechanism of Action: Antagonize receptors of vestibular excitation.
Examples: Dimenhydrinate (Gravol), meclizine (Dramamine), Diclectin (doxylamine + pyridoxine hydrochloride).

Ginger

Medication: Ginger gravol (herbal therapy).
Mechanism of Action: Increases intestinal emptying.
Safety: Safe in moderate doses.

Antimuscarinic Anticholinergic Medications

Mechanism of action: Reduce vestibular excitation.
Example: Scopolamine (Hyoscine) - available in transdermal patches, IV, and oral forms.

Serotonin Antagonist Medications

Mechanism of action: 5HT3 receptor antagonism.
Example: Ondansetron (Zofran) - available in oral and IV forms.

Dopamine Antagonist Medications

Mechanism of action: D2 receptor antagonism.
Examples: Metoclopramide (Maxeran, Reglan), prochlorperazine (Stemetil) - available in oral, IV, and subcutaneous forms.
Side Effects: Sedation.

Cannabinoid Medications

Mechanism of action: CB1 and CB2 receptor agonism.
Examples: Dronabinol (Marinol), Cesamet /Nabilone, cannabis.
Agonism Effects: Affects other neurotransmitters like serotonin, GABA, and dopamine.

Summary of Treatment

Rehydration: Essential for managing dehydration and electrolyte imbalances.
Antidiarrheal medications: Opioid-based medications and atropine.
Nausea and vomiting medications: Target specific receptors with antihistamines, antimuscarinic anticholinergics, serotonin antagonists, dopamine antagonists, and cannabinoids.
Laxatives: Bulk-forming, softeners, stimulants, osmotics, and lubricants.
Anti-bloating medications: Gas X (simethicone) and Beano (alpha-d-galactosidase).

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Description

Test your knowledge on gastrointestinal (GI) terminology and anatomy. This quiz covers key concepts such as host flora, congenital malformations, and the structure and function of the small and large intestines. Perfect for anyone studying GI health or related fields.