Disorders of the GI Tract, Accessory Organs, and Pediatric GI Conditions

Comprehensive vocabulary review flashcards covering gastrointestinal disorders, mechanical and functional intestinal obstructions, appendicitis, acute pancreatitis, cholelithiasis, cholecystitis, fluid therapy, relevant pharmacotherapy, and pediatric conditions.

Intestinal Obstruction

Any condition that prevents the normal flow of chyme through the lumen of either the small or large intestine.

Paralytic Ileus

A functional, non-mechanical bowel obstruction characterized by the failure of intestinal motility, absent bowel sounds, constant abdominal pain, nausea, and inability to pass flatus, commonly seen postoperatively (such as postoperative day $2$ after bowel resection).

Mechanical Obstruction

A physical blockage of the intestinal lumen caused by intrinsic or extrinsic factors such as adhesions, tumors, hernias, or volvulus.

Functional Obstruction

An impairment of intestinal propulsion without an anatomical or physical obstruction, typically caused by neural dysfunction, electrolyte imbalances, peritonitis, or anesthesia.

Simple Obstruction

A mechanical blockage of the intestinal lumen occurring without associated impairment of vascular flow or mesenteric ischemia.

Strangulated Obstruction

An acute intestinal obstruction with compromised mesenteric blood supply, rapidly producing tissue ischemia, necrosis, perforation, and peritonitis.

Closed-Loop Obstruction

An obstruction where a bowel segment is occluded at two points along its length, creating an isolated lumen with rapidly elevating intraluminal pressure and a high risk of strangulation.

Volvulus

A condition in which a segment of the intestine twists around its mesenteric axis, causing mechanical obstruction and compromising or blocking blood flow.

Third Spacing (in SBO)

The pathological shift of fluid and electrolytes into the intestinal lumen and peritoneal cavity caused by increased secretion and impaired absorption, leading to intravascular volume depletion and hypovolemia.

Bacterial Translocation

The migration of intraluminal bacteria across a damaged, ischemic, and edematous mucosal barrier into mesenteric lymph nodes and the bloodstream, potentially resulting in sepsis.

Pyloric Obstruction

A gastrointestinal blockage located at the gastric outlet characterized clinically by early, profuse vomiting of clear gastric secretions and undigested food without bile.

Metabolic Alkalosis (in Early SBO)

An acid-base disturbance occurring in the early stages of high or proximal intestinal obstruction due to persistent vomiting and the profound loss of gastric hydrochloric acid ($H^+$ and $Cl^-$ ions).

Metabolic Acidosis (in Prolonged SBO)

An acid-base disturbance developing in prolonged or ischemic intestinal obstruction caused by the loss of alkaline bicarbonate ($HCO_3^-$) secretions and the accumulation of lactic acid from tissue ischemia.

Hypokalemia (in GI Obstruction)

A critical depletion of serum potassium ($K^+$) caused by persistent vomiting and third spacing that impairs smooth muscle contractility and exacerbates bowel distention.

Appendicitis

Acute inflammation of the vermiform appendix commonly triggered by luminal obstruction (e.g., a fecalith or tumor), resulting in increased intraluminal pressure, hypoxia, bacterial invasion, and risk of perforation.

Fecalith

A hard, calcified mass of inspissated fecal matter that acts as the primary mechanical cause of luminal occlusion in acute appendicitis.

McBurney Point

The anatomic landmark located one-third of the distance from the anterior superior iliac spine to the umbilicus, where localized rebound tenderness typically presents in acute appendicitis.

Acute Pancreatitis

Inflammation of the pancreas caused by cellular injury and autodigestion from prematurely activated enzymes within pancreatic tissue, most commonly linked to gallstones or alcohol consumption.

Autodigestion

The premature, intra-acinar activation of digestive proenzymes (such as trypsinogen to trypsin) that degrade pancreatic parenchyma, blood vessels, and adjacent peripancreatic fat.

Serum Lipase

A diagnostic enzyme produced by pancreatic acinar cells that remains elevated longer than amylase in the bloodstream and serves as a primary marker for diagnosing acute pancreatitis.

Cullen Sign

A bluish periumbilical ecchymosis indicative of retroperitoneal hemorrhage and severe acute necrotizing pancreatitis.

Grey Turner Sign

Flank ecchymosis caused by the tracking of retroperitoneal blood, signaling severe hemorrhagic pancreatitis and poor prognosis.

Morphine

A potent opioid analgesic that binds to $\mu$ and $\kappa$ opioid receptors to provide profound analgesia, euphoria, and sedation, requiring close monitoring of respiratory rate, blood pressure, and bowel elimination.

Crystalloids

Aqueous electrolyte solutions (such as $0.9\%$ Normal Saline or Lactated Ringer's) that move readily across capillary membranes into interstitial spaces, where only approximately $25\%$ remains intravascular.

Colloids

Intravenous solutions containing large, non-diffusible macromolecules (such as albumin, dextran, or hetastarch) that exert oncotic pressure to expand intravascular plasma volume.

Cholelithiasis

The formation of stones in the gallbladder, predominantly resulting from cholesterol supersaturation, biliary stasis, and gallbladder hypomotility.

Biliary Colic

Episodic, steady, cramping pain in the epigastrium or right upper quadrant radiating to the shoulder or scapula, triggered by fatty meals stimulating gallbladder contraction against an obstructed cystic duct.

Cholecystitis

Inflammation of the gallbladder wall, most commonly occurring when an impacted gallstone lodges in the cystic duct, causing mucosal ischemia and secondary bacterial infection.

Ketorolac

A nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase to reduce prostaglandin synthesis, restricted to short-term therapy ($\le 5$ days) due to renal and bleeding risks.

Cefotaxime

A parenteral third-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, providing bactericidal activity against gram-negative pathogens in cholecystitis and appendicitis.

Metronidazole

A nitroimidazole antibiotic that enters microbial cells and disrupts DNA and protein synthesis, indicated for treating anaerobic infections associated with cholecystitis and appendicitis.

Intussusception

The telescoping of a proximal segment of intestine (intussusceptum) into a distal segment (intussuscipiens), representing the most frequent cause of bowel obstruction in infants aged $5$ to $7$ months.

Currant-Jelly Stool

A clinical finding characteristic of intussusception consisting of dark red, gelatinous stool mixed with mucus and sloughed, ischemic intestinal mucosa.

Necrotizing Enterocolitis (NEC)

A severe acute gastrointestinal inflammatory disease characterized by ischemic necrosis of the bowel wall, seen predominantly in premature and low-birth-weight infants ($< 1500\,g$).

Biliary Atresia

A congenital or perinatal malformation characterized by progressive inflammatory destruction and fibrosis of the extrahepatic bile ducts, producing neonatal cholestasis and jaundice.

Acholic Stools

Pale, clay-colored feces resulting from the total failure of bile pigments (bilirubin/stercobilin) to pass through the biliary ducts into the intestinal lumen, seen in biliary atresia.

Kasai Portoenterostomy

A surgical palliative procedure for biliary atresia that resects the atretic extrahepatic bile ducts and anastomoses a segment of jejunum to the porta hepatis to establish bile drainage.