36. Digestive Alterations Flashcards
a non absorbable substance in the intestine draws excess water into the intestine and increases stool weight and volume; causes large-volume diarrhea
osmotic diarrhea
excessive mucosal secretion of fluid and electrolytes produces large volume diarrhea; can have infectious causes
secretory diarrhea
excessive motility decreases transit time and opportunity for fluid absorption resulting in diarrhea
motility diarrhea
characterized by frank bright red blood or dark, grainy digested blood (“coffee grounds”) that has been affected by stomach acid
upper GI bleeding (esophagus, stomach, duodenum)
bleeding from the jejunum, ilium, colon, or rectum
lower GI bleeding
usually caused by slow, chronic blood loss that is not obvious and results in iron deficiency anemia
occult bleeding
bright red stools
hematochezia
black tarry stools that are sticky and have a characteristic foul odor
melena
difficulty swallowing
dysphagia
2 types of dysphagia
- mechanical obstruction - functional dysphagia (neural or muscular disorders)
rare form of dysphagia related to loss of inhibitory neurons in the myenteric plexus w/ smooth muscle atrophy in the middle/lower parts of esophagus
achalasia
What does achalasia lead to?
altered esophageal peristalsis and failure of lower esophageal sphincter (LES) to relax -> can cause distention/obstruction in esophagus
how do people manage symptoms of achalasia
- eat small meals slowly - drink fluids with meals - sleep w/ head elevated to prevent regurgitation/aspiration
reflux of acid and pepsin or bile salts from the stomach into the esophagus that causes esophagitis
gastroesophageal reflux disease (GERD)
abnormalities in the LES, esophageal motility, and gastric motility or emptying can cause what?
GERD
type of diaphragmatic hernia w/ protrusion of the upper part of the stomach through the diaphragm into the thorax
hiatal hernia
proximal portion of stomach moves into the thoracic cavity through the esophageal hiatus
sliding hiatal hernia (type 1; most common)
herniation of the greater curvature of the stomach through a secondary opening in the diaphragm alongside the esophagus
paraesophageal hiatal hernia (type 2)
What can having a portion of the stomach above the diaphragm (type 2 hiatal hernia) cause?
- congestion of mucosal blood flow -> gastritis and ulcer formation - strangulation of the hernia (medical emergency)
delayed gastric emptying in the absence of mechanical gastric outlet obstruction
gastroparesis
narrowing or blocking of the opening between the stomach and the duodenum (can be congenital or acquired)
pyloric obstruction (gastric outlet obstruction)
most common acquired cause of pyloric obstruction
- peptic ulcer disease or carcinoma near pylorus - duodenal ulcers more likely to cause obstruction
caused by any condition that prevents the normal flow of chyme through the intestines; can occur in small or large bowel
intestinal obstructions
mechanical blockage of the intestinal lumen by a lesion (most common type of intestinal obstruction)
simple obstruction
failure of intestinal motility often occurring after intestinal or ABD surgery, acute pancreatitis, or hypokalemia
paralytic ileus (functional obstruction)
7 common causes of intestinal obstruction
- hernia - intussusception - torsion (volvulus) - diverticulosis - tumors - paralytic ileus - fibrous adhesions (post-op; Crohn’s)
less common bowel obstruction that is usually related to cancer
large bowel obstruction
most common type of bowel obstruction
small bowel obstruction (SBO)
What does an intestinal obstruction lead to?
accumulation of fluid/gas proximal to obstruction
How would a bowel obstruction lead to pneumonia?
- distention -> pressure on diaphragm -> decreased respiratory volume -> atelectasis -> pneumonia
How would a bowel obstruction lead to peritonitis?
- distention and prolonged increased of wall tension -> decreased venous return -> bowel edema -> increased capillary permeability (fluid loss into peritoneum) -> bacterial translocation to peritoneum
How would a bowel obstruction lead to loss of water/electrolytes and dehydration?
- ABD pain leads to N/V, decreased intake, decreased nutrient absorption, and decreased carb reserves (ketosis)
When does a bowel obstruction leads to alkalosis or acidosis?
- alkalosis (early or high obstruction) - acidosis (late or low obstruction)
What 2 electrolytes are affected most by a bowel obstruction?
- K (hypokalemia) - Cl (hypochloremia)
How would a bowel obstruction lead to shock?
- distention -> increased capillary permeability - dehydration from loss of water/electrolytes - both lead to hypovolemia -> shock
inflammatory disorder of the gastric mucosa; can be acute or chronic
gastritis
break or ulceration in the protective mucosal lining of the lower esophagus, stomach, or duodenum
peptic ulcer
2 most common causes of ulcers
NSAIDs and H. Pylori infection (both are erosive factors)
most common type of peptic ulcer
duodenal ulcer (also caused by NSAIDs and H. Pylori)
ulcers that occur in the stomach; often associated w/ chronic gastritis
gastric ulcers
How do gastric ulcers form?
- caused H. Pylori, NSAIDS, bile salts, alcohol, or ischemia - damage to mucosal barrier -> decreased function of mucosal cells -> diffusion of acid into gastric mucosa - formation of histamine -> increased acid production, increased capillary permeability and mucosal edema - conversion of pepsinogen to pepsin causes further erosion and bleeding -> ulcer
Consequences of upper and lower GI bleeding
- blood volume depletion -> decreased CO -> compensatory constriction of peripheral arteries - decreased blood flow to kidneys (renal failure) - decreased blood flow to GI structures -> bowel/liver infarction/necrosis - decreased blood flow to brain and heart - metabolic acidosis -> lactic acidosis -> death
7 postgastrectomy symptoms
- dumping syndrome - alkaline reflux gastritis - afferent loop obstruction - diarrhea - weight loss - anemia - bone/mineral disorders
rapid emptying of hypertonic chyme from surgically residual stomach into the small intestine 10-20 minutes after eating; can cause N/V, osmotic diarrhea, pain, and hypotension
dumping syndrome
stomach inflammation caused by reflux of bile and alkaline pancreatic secretions containing proteolytic enzymes
alkaline reflux gastritis
cause of anemia after gastrectomy
loss of IF -> B12 deficiency -> pernicious anemia
lactose intolerance is due to what?
deficiency in lactase (enzyme that breaks down lactose)
Chief problem of pancreatic insufficiency
fat malabsorption -> steatorrhea
chronic inflammatory disease that causes ulceration of the colonic mucosa (most common in rectum and sigmoid colon)
ulcerative colitis (UC)
idiopathic inflammatory disorder that affects any part of the GI tract from the mouth to the anus; spreads with discontinuous transmural involvement (skip lesions)
Crohn’s disease (CD)
most common sites of CD
ascending colon and transverse colon
symptom based disease characterized by recurrent ABD pain w/ altered bowel habits
Irritable bowel syndrome (IBS)
herniations or saclike outpouchings of the mucosa and submucosa through the muscle layers usually in the wall of the sigmoid colon
diverticula
asymptomatic diverticular disease
diverticulosis
diverticulosis w/ inflammation of diverticula
diverticulitis
inflammation of the vermiform appendix (projected from the apex of the cecum)
appendicitis
Internal vs external hemorrhoids
- internal: may see bright red blood (not painful) - external: dilation of veins below the pectinate line (painful)
obesity’s affect on adipocytes
- insulin resistance - increased lypolysis - increased inflammation
obesity’s affect on pancreas and liver
- pancreas: increased insulin secretion (due to insulin resistance) - liver: insulin resistance, increased gluconeogenesis and glycogenolysis
increased ghrelin from the stomach causes what?
increased appetite -> signals hypothalamus
common complications of obesity
- cardiovascular problems (HTN, CAD, stroke, MI) - pulmonary (sleep apnea, asthma) - endocrine (NIDDM, infertility) - MSK (OA, low back pain, plantar fasciitis) - GI (GERD, gallstones, fatty liver)
4 cancers associated w/ obesity
- breast - colon - renal - endometrial
abnormally high blood pressure in the portal venous system caused by resistance to blood flow
portal HTN
portal HTN commonly causes what?
- esophageal varices - splenomegaly - caput medusae (ABD varices) - hemorrhoidal varices (internal hemorrhoids)
most common cause of ascites
cirrhosis
Mechanisms that cause ascites
- portal HTN -> increased lymph production -> leakage into peritoneal space and decreased plasma volume - hepatocyte failure -> decreased albumin synthesis -> decreased oncotic pressure in capillaries - altered metabolism + decreased renal flow -> increased RAAS
complex neurologic syndrome caused by accumulation of toxins normally removed from the liver and circulation into the brain
hepatic encephalopathy
most hazardous toxin not removed from liver during hepatic ecephalopathy
- ammonia (end produce to protein digestion) -> usually converted to urea
What plasma concentration of bilirubin is considered hyperbilirubinemia
greater than 2.5-3.0 mg/dL
causes of hyperbilirubinemia
- post hepatic obstruction to bile flow - intrahepatic obstruction - prehepatic excessive production of unconjugated biluribn (hemolysis of RBC)
increased destruction of erythrocytes causes what type of jaundice
prehepatic (unconjugated)
decreased liver ability to excrete bilirubin causes what type of jaundice
intrahepatic obstructive jaundice (both conjugated and unconjugated)
bile duct obstruction (cholestasis) causes what type of jaundice
extra hepatic obstructive jaundice (conjugated)
rare clinical syndrome resulting in severe impairment of liver cells without preexisting liver disease or cirrhosis
acute liver failure (fulminant liver failure)
most common causes of acute liver failure
- acetaminophen overdose (most common) - Hepatitis B
irreversible inflammatory, fibrotic liver disease
cirrhosis
clinical manifestations of cirrhosis
- portal HTN (ascites, varices, splenomegaly) - decreased bilirubin metabolism (jaundice) - decreased bile in GI tract (light colored stools) - decreased vitamin K absorption (bleeding) - decreased hormone metabolism and increased androgens/estrogens - decreased protein, fat, and carb metabolism - toxin accumulation (hepatic encephalopathy)
lab changes seen with cirrhosis
- increased AST and ALT - increased bilirubin - low serum albumin - prolonged PT - elevated alkaline phosphatase
infiltration of hepatocytes with fat (primarily triglycerides) in the absences of alcohol intake; associated w/ obesity
nonalcoholic fatty liver disease
What forms before cirrhosis
- alcoholic fatty liver (steatosis) - alcoholic steatohepatitis (alcoholic hepatitis)
systemic viral disease that mainly affects the liver
viral hepatitis
5 types of hepatitis and their routes
- Hep A (fecal-oral; most common), parenteral, sexual - Hep B (parenteral, sexual, transplacental) - Hep C (parenteral, sexual, transplacental) - Hep D (Hep B coinfection, fecal-oral, sexual) - Hep E (fecal-oral)
clinical phases of hepatitis
- incubation - prodromal (highly transmissible) - icteric (acute illness) - recovery
types of hepatitis that cause chronic active hepatitis
- Hep B - Hep B/Hep D coinfeciton - Hep C
formed from impaired metabolism of cholesterol, bilirubin, and bile acids
gallstones
cardinal manifestations of cholelithiasis
- epigastric and right hypochrondrium pain - intolerance of fatty foods
cause of cholecystitis
gallstone lodged in the cystic duct -> causes gallbladder to become distended and inflamed
pathophysiology of acute pancreatitis
- duct obstruction -> acing cell injury - intracellular and extracellular activation of enzymes - lipase -> fat necrosis - trypsin, chymotrypsin, phospholipase, and elastase along w/ inflammation (complement and cytokines) cause cell injury, edema, thrombosis, hemorrhage, and necrosis
What can acute pancreatitis lead to?
- shock - SIRS - ARDS - acute tubular necrosis (ATN) - coagulation disorders - translocation of intestinal bacteria -> sepsis - pancreatic abscess
most common cause of chronic pancreatitis
chronic alcohol abuse
closely associated w/ development of colorectal cancer
colorectal polyps
premalignant lesions
neoplastic polyps (tubular most common)
most common type of colorectal polyps
hyperplastic (nonneoplastic or benign)
signs and symptoms of colorectal cancer
- pain - mass - change in bowel habits - blood in stool - anemia
