Term
| 3 basic processes of GI tract |
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Definition
| Ingestion, Digestion (secretion/absorption), Motility |
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Term
| What is skeletal muscle needed for in the GI tract? |
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Definition
| Continence @ sphincters, chewing, initiation of swallowing |
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Term
| Difference between skeletal & smooth muscle |
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Definition
| Smooth muscle has graded contractions, is mononucleated, can contract autonomously |
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Term
| Characteristic contraction of GI smooth muscle |
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Definition
| SLOW and MAINTAINED; have a resting tone to GI smooth muscle |
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Term
| What does the ENS control? |
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Definition
Regulate motility, secretion, absorption
Complete sensory and motor pathways - NOT PAIN |
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Term
| Key symptom of pathology relating to the ENS? |
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Definition
| PAIN - it is not sensed by the ENS, and indicates pathology |
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Term
| Where do external pain fibers run to/from the GI tract? |
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Definition
| Nociceptive fibers run from DRG to mucosa of GI tract to mediate pain |
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Term
| Likely reasons for pain in the GI tract |
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Definition
High luminal pressure
Wall distension |
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Term
| What is true of all inflammatory conditions targeting the epithelium of the GI tract? |
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Definition
DECREASE SURFACE AREA
Therefore see decreased absorption, secretion, and barrier function |
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Term
| What forms physical barrier between GI lumen and the body? |
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Definition
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Term
| Type of epithelium in intestines? |
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Definition
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Term
| Where are immune cells present in the GI tract? |
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Definition
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Term
| What type of immune cells are seen in the GI tract? |
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Definition
Eosinophils, neutrophils, monocytes, T cells
Mast cells primed with IgE (type I hypersensitivity) |
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Term
| What is the acute response to inflammation in the GI tract? |
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Definition
Emesis, diarrhea (clear out contents)
Localized pain to inflamed area & loss of function |
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Term
| General characteristics of gastroenteritis |
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Definition
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Term
| Acute vs. Chronic Inflammation |
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Definition
Acute - short lived response to presence of irritant
Chronic - LONG term response to persistent stimulus OR persisting in the absence of any stimulus (e.g. IBD) |
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Term
|
Definition
| Fundus (proximal), body, antrum (distal) |
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Term
|
Definition
Evidence of CNS and GI involvement
Many stimuli
Usually a symptom of a larger pathology |
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Term
|
Definition
Stimulation of vomiting centers in medulla
Hypersalivation from parasymp innervation and glottis closes to protect airway; relaxation of LES, reverse peritalsis & contraction of abdominal muscles |
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Term
| What type of inflammation is seen in gastritis? |
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Definition
| CHRONIC inflammation of the stomach |
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Term
| Different causes of gastritis (chronic inflamm) |
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Definition
H. pylori infection - leads to ulceration (compromised mucosal defense barrier)
NSAID injury (ischemia caused by NSAIDs)
Excess HCl secretion
Gastric cancer |
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|
Term
| How can you treat excess acid secretion leading to gastritis? |
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Definition
| Proton pump inhibitors, H-channel blockers |
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Term
|
Definition
"Dumping" syndrome - early dumping into duodenum
Vomiting, diarrhea
May be due to decreased gastric volume from BARIATRIC surgery; other is idiopathic |
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Term
|
Definition
Delayed emptying - imbalance of luminal and neural signals
Associated with DM - chronic DM causes peripheral neuropathy in ENS |
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Term
|
Definition
NO emptying
Congenital defect in pyloric sphincter - no inhibitory innervation to sphincter (always contracted)
Use myectomy to enlarge pylorus |
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Term
| Types of bariatric surgery |
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Definition
Restrictive Operations - reduce gastric VOLUME; much more common
Malabsorptive Operations - bypass small intestine to reduce ABSORPTION |
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Term
| 3 major types of restrictive bariatric surgery |
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Definition
Roux-En-Y
Gastric Banding
Sleeve Gastrectomy |
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|
Term
|
Definition
40% of restrictive operations
Good for comorbidities (DM II)
Connect piece of small intestine to fundus (bypass rest of stomach) to reduce gastric volume |
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|
Term
|
Definition
43% of restrictive surgeries
Minimally invasive (laproscopic)
Tie band around fundus to reduce gastric volume |
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|
Term
|
Definition
4% of restrictive operations
Stomach is stapled and sleeve placed over top to limit expansion |
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Term
| Description of PUBLICALLY funded bariatric surgery |
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Definition
21 month wait time
Roux-En-Y is performed (small intestine attached to fundus)
Better for comorbidities
Major surgery & highly invasive - risks |
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Term
| Description of PRIVATELY funded bariatric surgery |
|
Definition
1 month wait time - $16k (median cost)
Gastric banding performed (minimally invasive)
Safer procedure, ambulatory |
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Term
| Most common comorbidity to obesity |
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Definition
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Term
| What is the primary role of the liver? |
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Definition
| Secretion of bile acids/salts (fat absorption) |
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Term
| Why is the liver tolerant of insult? |
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Definition
| Because of its regenerative capacity; only visceral organ which can regenerate |
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Term
| Different name for biliary colic |
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Definition
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Term
| Where can the blockage in biliary colic occur? |
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Definition
| Either in bile outflow duct from gallbladder or in the duct emptying into duodenum |
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Term
| Type of pain seen in biliary colic |
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Definition
|
|
Term
| Complications of biliary colic? |
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Definition
|
|
Term
| Treatment of biliary colic |
|
Definition
Surgical removal of stone or gall bladder
Lithotripsy to break down
Drugs to dissolve |
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Term
| 3 different causes of JAUNDICE: |
|
Definition
Overall it shows excessive bilirubin levels in blood
May be too much is produced - hemolysis of RBCs
Not enough removed BY liver - key aspect of HEPATITIS
Not enough removed FROM liver - obstruction |
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|
Term
|
Definition
Caused by HAV
Highly contagious; have vaccine
Contracted from water/environment; ACUTE |
|
|
Term
|
Definition
Caused by HBV; "serum" hepatitis
Blood borne disease
Chronic |
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|
Term
|
Definition
Caused by HCV; blood-borne (like B)
Chronic w/ associated cancer risk |
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|
Term
|
Definition
Requires B to be co-morbid for HDV to infect
Blood borne; ACUTE |
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|
Term
|
Definition
Not present in USA; caused by HEV
Blood/environment spread; ACUTE |
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Term
| Non-viral causes of hepatitis? |
|
Definition
Chemical - acetominophen, EtOH, benzene
Cancer - liver is main site of cancer formation; common site of metastasis |
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|
Term
| What is cirrhosis considered to be? |
|
Definition
| The outcome of CHRONIC liver damage |
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Term
| Pathology associated with cirrhosis |
|
Definition
Loss of hepatocyte function
Increased circulating bilirubin (jaundice), but decreased bile production (decreased fat absorption)
Impaired detoxification of N-compounds
Encephalopathy |
|
|
Term
| Which symptoms are common to both hepatitis and cirrhosis? |
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Definition
| Loss of hepatocyte function - jaundice from increased bilirubin in blood and decreased bile production; also get decreased fat absorption |
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Term
| What causes the loss of hepatocyte function in cirrhosis? |
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Definition
| FIBROSIS - scar tissue forms in the liver |
|
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Term
| At what point(s) can liver damage be reversed? |
|
Definition
If EtOH intake stops at fatty liver OR alcoholic hepatitis, damage may be reversed
However, if cirrhosis is reached, then damage is PERMANENT |
|
|
Term
| What are the vascular effects of cirrhosis? |
|
Definition
Fibrosis impedes blood flow leading to PORTAL HTN - restricts flow entering liver, get-back up
Because of backup get systemic HTN in veins
Get ascites and varices |
|
|
Term
| What are side-effects which occur because of portal HTN seen in cirrhosis? |
|
Definition
Ascites (fluid accumulation in peritoneum)
Varices in the spleen leading to splenomegaly |
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Term
| 2 main functions of pancreas |
|
Definition
Exocrine enzyme secretion & HCO3-
Endocrine secretion of insulin & glucagon |
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Term
|
Definition
Gallstone
Alcoholic
Infectious |
|
|
Term
|
Definition
Blockage of pancreatic outflow by gallstone, get autodigestion by enzymes
Treat by gallbladder removal |
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Term
|
Definition
| Triggers early activation of pancreatic enzymes = autodigestion; feed-forward process causes mass enzyme activation |
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Term
|
Definition
| Due to bacterial infection of pancreas |
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|
Term
| Symptoms of General Pancreatitis: |
|
Definition
Decreased pancreatic function
SEVERE pain (unrelenting)
Complications = sepsis, perforation, peritonitis |
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Term
| Main functions of small intestine? |
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Definition
| Absorption/secretion, motility, neutralize gastric HCl |
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Term
| Main functions of large intestine? |
|
Definition
|
|
Term
| What are the main functions of intestinal epithelium? |
|
Definition
| Barrier for protection, secretion/absorption, constant proliferation, enzyme secretion |
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|
Term
|
Definition
| About 9 L in total (8 L secreted into GI lumen by epithelium); need to balance with reabsorption |
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Term
| How is the pathology of intestinal mucosa prevented? |
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Definition
| Constant challenge - sampling of luminal contents by immune system |
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Term
| What is the immune response in celiac disease? |
|
Definition
Antibodies formed against GLIADIN (gluten byproduct)
Immune reaction causes inflammation of villi and flattening of them - FLAT MUCOSA |
|
|
Term
| What occurs to the mucosa in Celiac disease? |
|
Definition
Get FLAT MUCOSA - villi are all flattened
B/c of mucosal pathology, enzyme and absorption functions are decreased |
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Term
| What does NOT occur in Celiac disease? |
|
Definition
NO enzyme deficiency or digestive block
NOT an autoimmune condition |
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|
Term
|
Definition
NOT an allergy (not type I hypersensitivity mediated by IgE)
Bacterial response to undigested lactose (lactase deficiency) |
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|
Term
| What causes the symptoms of lactose intolerance? |
|
Definition
Bacteria fluorish on undigested lactose present because of a lactase deficiency
Actually, lactase deficiency is very common (most people are, just have varying degrees) |
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|
Term
| What causes food allergies? |
|
Definition
| Antigen recognition by mast cells primed w/ IgE |
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|
Term
| Symptoms of food allergy? |
|
Definition
Gut is the primary target, then reaction goes systemically
Pain, diarrhea, hives, anaphylaxis |
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|
Term
| What is used to determine sensitivity to an allergy? |
|
Definition
| Oral challenge b/c primed mast cells located under tongue |
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Term
| Amount of microbes present in GI tract? |
|
Definition
10^5 in ileum
10^9 in colon |
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Term
|
Definition
| O157 H7 - enterohemorrhagic E. coli (EHEC) |
|
|
Term
| Where is O157H7 E. coli native to, and what are its symptoms in infection of us? |
|
Definition
Native to the gut of cattle
Causes - pain, bloody, diarrhea, vomiting, hemolysis, kidney damage |
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Term
| What is the worst case scenario to treat infection of the gut? |
|
Definition
| Antibiotics - throws off the normal probiotic environment of the gut |
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|
Term
|
Definition
C. difficile is NORMAL FLORA of GI tract, BUT when given certain antibiotics increases C.D population in gut which causes toxin secretion
Possible treatment w/ stool transplant - replace unbalanced flora w/ normal flora |
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Term
| Two different causes of diarrhea |
|
Definition
Increased H2O secretion into lumen
Decreased H2O absorption from lumen
BOTH caused by ion imbalance (underlies fluid movement) |
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Term
| What does an increased fluid volume in the gut cause? |
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Definition
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Term
| Treatment of Traveler's diarrhea |
|
Definition
Immodium - anti-motility agent, reduce cramping
Pepto Bismol - decreased frequency of stool and duration
Antibiotics - worst case scenario |
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Term
| Main symptoms of appendicitis |
|
Definition
Pain in RLQ (can be episodic or unremitting); unremitting pain post-rupture
Rupture forms abscess, but may be walled off by omentm |
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Term
| What occurs if a ruptured appendix is NOT walled off by the omentum? |
|
Definition
|
|
Term
| Types of mechanical intestinal obstructions |
|
Definition
Intussusception
Volvulus
Adhesions
Strangulation |
|
|
Term
|
Definition
"Telescoping of gut" b/c of loose mucosa
Mucosal folding traps mesentery & compresses BV's - ischemia, necrosis, peritonitis if ruptures
Colicky, cramping pain; jelly diarrhea |
|
|
Term
|
Definition
Twist in loop of gut (like kink in garden hose)
Due to defective mesentery
See dilatation of gut where volvulus is
Colicky cramping pain |
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|
Term
|
Definition
Mechanical obstruction - inappropriate connections
Occurs because of something WITHIN INTESTINE - inflammation, surgery
Dilatation upstream of adhesion due to obstructed movement |
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|
Term
| Strangulation of Intestine |
|
Definition
Mechanical obstruction - complete ischemia to region causing NECROSIS
Associated w/ INGUINAL hernia - loop of intestine may herniate through muscle, entrap and constrict |
|
|
Term
| Type of pain involved in obstruction of intestine? |
|
Definition
| COLICKY, CRAMPING Pain (associated with peristaltic contractions) |
|
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Term
| Two types of congenital obstructive disorders |
|
Definition
Atresia - blind end of intestine
Hirschprungs - colonic aganglionosis |
|
|
Term
|
Definition
Blind ended intestine; non continuous
Need surgical resection |
|
|
Term
|
Definition
Aganglionosis in distal colon
Tonic contraction in affected region b/c of no inhibitory input
Obstruction, upstream back-up, megacolon |
|
|
Term
| What is a failure in gut motility known as? |
|
Definition
|
|
Term
| What is the progression of a mechanical obstruction of the gut? |
|
Definition
Start w/ vomiting, cramping pain, diarrhea - increased secretions and blockage leads to EDEMA
Complete obstruction completely inhibits absorption, get a lack of fluid movement leading to bacterial overgrowth - ischemia & necrosis, possibly leading to ulceration/abscess |
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|
Term
| What does a complete gut obstruction result in? |
|
Definition
Failure of gut motility = ILEUS
Lose all bowel sounds
Risk of perforation and peritonitis from bacterial infection |
|
|
Term
| Characteristic symptoms of ileus |
|
Definition
No bowel sounds
No reflex contractions
No colicky pain |
|
|
Term
| What is associated with onset of ileus (what causes it)? |
|
Definition
| GI pathology OR following a GI surgical procedure (due to ENS, get quick recovery) |
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|
Term
| What is unique about the omentum and its involvement in healing? |
|
Definition
| Omentum can rapidly mobilize to wall off an abscess or perforation/inflammation |
|
|
Term
| Why is bacterial infection in the peritoneal cavity ideal? |
|
Definition
| Because the peritoneal cavity is not supported by the immune system |
|
|
Term
| Key symptoms of peritonitis |
|
Definition
GUARDING - board like abdomen (reflex); UNREMITTING PAIN (NOT colicky like in obstructive conditions)
Ascites - fluid accumulation in peritoneal cavity
Ileus & systemic infection |
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|
Term
| In the presence of a perforation of the gut due to bacterial infection/ileus, what can be done to prevent peritonitis from occurring? |
|
Definition
| Mobilization of the omentum to wall off the perforation/site of inflammation |
|
|
Term
| Different phases of swallowing? |
|
Definition
Voluntary - mastication, tongue movement
Pharyngeal - trigeminal & pharyngeal nerves commence |
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|
Term
|
Definition
Failure of LES relaxation (always constricted)
Defect in inhibitory ENS innervation |
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|
Term
| What is the primary symptom in GERD? |
|
Definition
| PAIN due to acid reflux into lower esophagus |
|
|
Term
| Different origins of GERD: |
|
Definition
Lax LES (open too often)
Excess HCl secretion
Hiatal hernia (often due to increased abdominal pressure) - fundus protrudes through hiatus in diaphragm |
|
|
Term
| What can long-standing GERD be a risk factor for? |
|
Definition
| Esophageal cancer (Barret's esophagus) - premalignant condition associated with prolonged GERD |
|
|
Term
| Differentials of different types of blood in the stool: |
|
Definition
Fresh = local source
Black/Tarry = upper GI source
Cryptic = detected chemically |
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|
Term
| Where are intestinal tumors most common (which cell type)? |
|
Definition
| Epithelial tumors (b/c constant proliferation) |
|
|
Term
| What type of blood in the stool is present with a hemorrhagic adenoma? |
|
Definition
| Often see bright red blood if present in the colon (fresh source) |
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|
Term
| Why can you resect segments of the intestine WITHOUT a loss of function? |
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Definition
| Because normally, the intestinal epithelia is functioning well below its maximum - after resection can increased absorption/secretion to continue normal GI function |
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|
Term
| What is one thing you need to be weary about after any major GI sx? |
|
Definition
|
|
Term
| Most common cause of overt blood stool? |
|
Definition
|
|
Term
|
Definition
| Contractions of CIRCULAR smooth muscle to form ring-like segments of the colon |
|
|
Term
|
Definition
COMPLETELY NORMAL (no associated pathology)
Small outpockets of colonic wall through mucosa
May be due to low fiber diet |
|
|
Term
|
Definition
Inflammation of diverticula
Difficult cause to establish (foods with small seeds?)
Acute pain (unremitting), signs of abscess/perforation (may lead to peritonitis) |
|
|
Term
| What is unique about the IBS diagnosis? |
|
Definition
| Diagnosis by EXCLUSION - diagnose IBS in the absence of a noticeable pathology |
|
|
Term
| Inclusive criteria for IBS |
|
Definition
Pain relieved by defecation
Duration of several months
Alternating nature of symptoms
"Trigger" factor |
|
|
Term
| What is the most frequently encountered disease in GI practice? |
|
Definition
|
|
Term
| What is the objective & subjective evidence for the existence of IBS? |
|
Definition
Differing patterns of haustra
Increased sensitivity to balloon distension in the gut (HYPERSENSITIVITY to distension) |
|
|
Term
|
Definition
| Pain, bloody stool, diarrhea, fever, leukocytosis (high WBC), weight loss, etc. |
|
|
Term
| 2 distinct diseases of IBD? |
|
Definition
Crohn's disease
Ulcerative colitis |
|
|
Term
| Similarities between Crohn's & UC? |
|
Definition
True chronic inflammation (persists in absence of known cause)
Idiopathic & have no cure
Treatment is symptomatic (treat symptoms) |
|
|
Term
| Treatment of IBD (for both Crohn's & UC): |
|
Definition
ASA's, antibiotics - reduce inflammation
Glucocorticoids/immunosuppressants
anti-TNF antibodies |
|
|
Term
| Crohn's Disease - Characteristics |
|
Definition
Can range from anywhere from mouth to anus (ileum most common)
Affects full thickness of wall (transmural)
See skip lesions (patches of inflammation) and cobblestoning (patterns of inflammation around normal mucosa) |
|
|
Term
| What are 2 outcomes of transmural inflammation, seen in one type of IBD? |
|
Definition
Seen in Crohn's disease
Abscess and adhesions; FISTULA = adhesion
Fibrosis & stricturing - obstructs affected segments |
|
|
Term
|
Definition
Resectioning of gut - often RECURRENT (need multiple sx)
Need multiple sx, so get short gut syndrome (decreases absorption of Vit B12) |
|
|
Term
| What symptoms are unique to UC? |
|
Definition
Occurs only in colon (colitis)
Affects only the mucosa (NOT transmural) |
|
|
Term
| Difference in disease prognosis in CD vs. UC? |
|
Definition
Crohn's - often recurrent, need multiple resectionings
Ulcerative Colitis - does NOT reappear after resection; can live w/o colon |
|
|
Term
| What occurs to the affected portion of the wall in Crohn's? |
|
Definition
| See wall thickened in affected segment |
|
|
Term
| UC is associated with an elevated risk of? |
|
Definition
| Adenocarcinoma formation in the colon |
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