The Gastrointestinal Tract Flashcards
What is the function of the GI Tract?
consumes, digests, and eliminates food
What does the Upper Division contain?
Oral Cavity
Pharynx
Esophagus
Stomach
What is the function of the upper division of the GI tract?
helps with food consumption
Start of chemical digestion
What does the Lower Division contain?
Small Intestine
Large Intestine
Anus
What is the function of the lower division of the GI tract?
absorption of nutrients
What does the Hepatobiliary System contain?
Liver
Gallbladder
Pancreas
What is the function of the hepatobiliary system of the GI tract?
accessory system that secreted digestive enzymes
What are the 4 layers of the GI wall?
Mucosa
Submucosa
Muscle
Serosa
What is the function of the peritoneum?
large serous membrane that lines the abdominal cavity
What layer is the parietal peritoneum?
outer layer
What layer is the visceral peritoneum?
inner layer
What is the peritoneal cavity?
space between the two layers
What is the function of the mesentery?
double layer of peritoneum containing blood vessels and nerves that supplies the intestinal wall
What is the epithelium?
most exposed part of the mucosa
What is the epithelium composed of?
simple columnar epithelium or stratified squamous epithelium
What cells can be found within the epithelium?
Goblet cells
Endocrine cells
What is the function of Goblet cells?
Secrete mucus
What is the function of Endocrine cells?
secrete hormones into blood
What does the lamina Propia contain?
Myofibroblasts
Blood Vessels
Nerves
Immune Cells
What is the muscularis mucosa?
Layer of smooth muscle
Helps with continued peristalsis
What layers are found within the Mucosa?
Epithelium
Lamina Propia
Muscularis Mucosa
What layers are found within the Submucosa?
Major Blood and lympathics vessels
Submucosal plexus
Elastic fibers with collagen
What layers are found within the Muscularis externa?
Circular Muscle
Myenteric Plexus
Longitudinal Muscle
What is the other name for the submucous plexus?
Meissner’s plexus
What is the function of the submucosa layer of the GI wall?
stretches with increased capacity
Maintains shape of the intestine
What is the function of the Muscular layer of the GI wall?
Continued Peristalsis
Movement of digested material out of and along the gut
What is the other name for the Myenteric Plexus?
Auerbach’s plexus
What is the serosa?
A serous membrane that covers the muscularis externa of the digestive tract in the peritoneal cavity
What is swallowing coordinated by?
Medulla swallowing center
Cranial Nerves V, IX, X, and XII
What do salivary glands secrete?
Bicarbonate
Salivary Lipase
What does the Stomach secrete?
Hydrochloric Acid Pepsin Gastric Lipase Intrinsic Factor Mucus
What is the action of bicarbonate?
moistens food
What is the action of salivary lipase?
digests food
What is the action of hydrochloric acid?
kills bacteria
What is the action of pepsin?
digests protein
What is the action of Gastric lipase?
Digests fat
What is the action of intrinsic factor?
Aids in vit. B12 absorption
What is the action of mucus?
protects the stomach lining
What is Agenesis?
the complete absence of the esophagus
What is Atresia?
incomplete development of the esophagus
What is more common: Agenesis or Atresia?
Atresia
Where does atresia occur most commonly?
at or near the tracheal bifurcation sometimes with a fistula
What is atresia usually associated with?
Congenital heart defects
Genitourinary Malformations
Neurologic Disease
When is atresia usually discovered?
shortly after birth when the baby regurgitates during feeding
What can atresia lead to?
Aspiration
Suffocation
Pneumonia
Severe fluid and Electrolyte imbalances
What is acquired stenosis?
inflammatory scarring
What can cause acquired stenosis?
GERD
Irradiation
Systemic Sclerosis
Caustic Injury
What is a Diaphragmatic Hernia?
Incomplete formation of the diaphragm allows the abdominal viscera to herniate into the thoracic cavity
What is Omphalocele?
Occurs when closure of the abdominal musculature is incomplete and the abdominal viscera herniates into a ventral membranous sac
What is Meckel’s Diverticulum?
True Diverticulum
Blind outpouching of the alimentary tract that communicates with the lumen
What causes Meckel’s Diverticulum?
Failed involution of the vitelline duct
What is the Vitelline duct and when is it normally supposed to disappear?
connects yolk sac to developing GI tract
after 9 weeks of gestation
What may also be present with Meckel’s Diverticulum?
Ectopic Pancreatic or gastric tissue
What are the classical Symptoms of Meckel’s Diverticulum?
Occult Bleeding = Bright red bleeding per rectum (BRBPR)
Abdominal pain resembling acute appendicitis or obstruction
What is the rule for Meckel’s Diverticulum and what does it mean?
Rule of 2s
Occurs in 2% of population Present within 2 ft. of ileocecal valve approx. 2 inches long 2X as common in men Symptomatic by age 2
What is pyloric stenosis?
Narrowing of pyloric areas of the stomach
What is pyloric stenosis caused by?
hyperplasia of pyloric muscularis externa which obstructs the gastric outflow tract
Who is pyloric stenosis more common in?
3-5X more common in males
How many live births does it occur in?
1 in 300-900
Who are at an increases risk of developing pyloric stenosis?
Monozygotic twins Dizygotic twins Siblings Turner Syndrome Trisomy 18 Exposure to erythromycin or azithromycin
When and what does pyloric stenosis present as?
3-6 weeks of life
New-onset regurgitation
Projectile, non-bilious vomiting after feeding
Frequent demands for re-feeding
What may aggravate pyloric stenosis?
Edema
Inflammatory Changes in mucosa and submucosa
What is the acquired form of pyloric stenosis?
Antral Gastritis
Peptic Ulcers close to pylorus
What causes Hirschsprung Disease?
Failure of migration of neural crest cells
What do neural crest cells form?
form the plexuses of the GI tract
Who is most at risk of developing Hirschsprung disease and how many live births does it occur in?
1 in 5000 births
Those with Down Syndrome
What does Hirschspring disease present with?
Failure to pass meconium in immediate postnatal period
No secretions or peristalsis of GI tract
What is the most important clinical feature of Hirschsprung disease?
Congenital Aganglionic MegaColon
What are the major threats of Hirschsprung Disease?
Enterocolitis
Fluid and Electrolyte Imbalances
Perforation
Peritonitis
What causes Achalasia?
Decreased Nitric Oxide and Vasoactive Intestinal Peptide
Increased Acetylcholine
What is Achalasia?
Increased tone of the lower esophageal sphincter
What are the symptoms of Achalasia?
Dysphagia for solids and liquids Difficulty in Belching Regurgitation Chest Pain Weight Loss
What is primary achalasia caused by?
Ganglion cell degeneration
What is secondary achalasia caused by?
Chagas Disease
Diabetic Neuropathy
Infiltrative Disorders (malignancy, amyloidosis, or sarcoidosis)
Lesions of dorsal motor nuclei (polio, surgical ablation)
What is secondary achalasia associated with?
Down syndrome
Alacrima
Adrenal insufficiency
What is esophagitis?
Inflammation of the esophagus
What is hematemesis?
vomiting of blood
What are the esophageal causes of Hematemesis?
Lacerations (Mallory-Weiss Syndrome) Esophageal Perforation (cancer) Varices (cirrhosis) Reflux Esophagitis (erosive) Esophageal ulcers Barrett esophagus Adenocarcinoma Squamous cell carcinoma
What is Reflux Esophagitis?
reflux of gastric contents into the lower esophagus
What is reflux esophagitis caused by?
Loose tone of lower esophageal sphincter
Increased Abdominal Pressure
What is the other name for reflux esophagitis?
GERD
What covers the tract from the mouth to the end of the esophagus?
stratified squamous epithelia
What covers the tract from the stomach to the anus?
ciliated columnar epithelium
What is the function of the ciliated columnar epithelium?
to protect that area from acid erosion
What causes increased abdominal pressure?
Alcohol/Tobacco Obesity CNS depressants Pregnancy Hiatal hernia Decreased gastric empyting
What is decreased gastric emptying called?
gastropiesis (sp?)
What are the clinical features of Reflux Esophagitis?
Heartburn
Dysphagia
Regurgitation of sour-tasting gastric contents
What are the complications of Reflux Esophagitus?
Ulceration Blood vomiting Melena Stricture development Barrett Esophagus
What is melena?
blood in stool
What are esophageal varices?
Abnormal dilation of the veins at the junction between the portal and systemic venous systems
What causes esophageal varices?
portal hypertension
Who are esophageal varices most present in?
nearly half of patients with cirrhosis
What is the concern with esophageal varices?
bleeding
What is Barrett Esophagus?
complication of chronic GERD characterized by intestinal metaplasia
What is the intestinal metaplasia that occurs in Barrett esophagus?
replacement of normal stratified squamous epithelium lining to simple columnar epithelium with goblet cells
What patients is Barrett esophagus most common in?
white males 40-60 yrs. old
What are patients with Barrett esophagus at an increased risk of having?
Esophageal adenocarcinoma
How is Barrett esophagus identified?
By endoscopy and biopsy
What is the 7th leading cause of cancer deaths?
Esophageal tumors
What are the two most common types of esophageal cancer?
Squamous cell carcinoma
Adenocarcinoma
Where does squamous cell carcinoma usually occur?
middle 3rd of esophagus
Where does adenocarcinoma usually occur?
lower 3rd of esophagus
Which esophageal cancer is most common in the US?
Adenocarcinoma
Which esophageal cancer is most common worldwide?
Squamous cell carcinoma
What are the risk factors for Squamous Cell carcinoma?
Alcohol and Tobacco use Caustic esophageal injury Achalasia Tylosis Plummer-Vinson syndrome Diet deficient in fruits and veggies Very hot beverages Genetic abnormalities in p53 and EGFR
What are the risk factors for Adenocarcinoma?
Barrett esophagus GERD Hiatal hernia Obesity Smoking Increased acid exposure - Zollinger ellison syndrome
What is Zollinger Ellison syndrome?
multiple gastrinomas
What are the Clinical Features of Esophageal Tumors?
Dysphagia Odynophagia Progressively increasing obstruction Prominent weight loss and debilitation Hemorrhage and sepsis
What is the 5 year survival rate of esophageal tumors?
<25%
What are the four major regions of the stomach?
Cardia
Fundus
Body
Antrum
What are the cardia and antrum lined by?
mucin secreting foveolar cells that form small glands
What do the antral glands contain?
G cells
What is the function of G cells?
release gastrin to stimulate parietal cells
What is the function of parietal cells?
secrete luminal acid
Where are parietal cells located?
Gastric fundus and body
What else does the gastric fundus and body contain?
chief cells
What is the function of chief cells?
produce and secrete digestive enzymes like pepsin
What is acute gastritis?
Inflammation of gastric mucosa
Diverse set of disorders marked by gastric injury or dysfunction
What are the causes of gastritis?
NSAIDs Alcohol Bile Stress Induced INjury Acute Mucosal Erosion or Hemorrhage - Curling Ulcers or portal hypertension
What are the asymptomatic symptoms of Gastritis?
variable degrees of:
Epigastric pain
Nausea
Vomiting
What are the severe symptoms of Gastritis?
Mucosal Erosion Ulceration Hemorrhage Hematemesis Melena Massive Blood Loss is rare
What do the crypts of leiberkahn contain?
stem cells
Paneth cells
What is the pathogenesis behind gastritis?
loss of protective mechanism
What is the pathogenesis of NSAID causes of gastritis?
Decrease in COX causing decrease in PGE2/I2 causing decreased mucosal protection
What is the pathogenesis of H. pylori causes of gastritis?
decreased hydrochloric acid
What is the pathogenesis of chemicals, alcohol, and radiation causes of gastritis?
direct epithelial injury
What is the pathogenesis of chemotherapy as the cause of gastritis?
decreased epithelial regeneration
What is the most common cause of Chronic gastritis?
H. pylori infection
What is the most common cause of non H. pylori chronic gastritis?
Autoimmune diseases
What does chronic gastritis normally present as?
antral gastritis with normal or increased acid production
How does H. pylori survice the harsh acidic conditions of the stomach?
By producing urease
What is the function of urease and how does it help the h. pylori?
It neutralizes stomach acid by reacting with urea to form ammonia which is toxic to human cells and causes an overproduction of stomach acid
What are the virulence factors of H. Pylori?
Flagella Urease LPS and Outer proteins Exotoxins Secretory enzymes Effectors Type IV secretion system
What is the function of the LPS and outer proteins?
adheres to host cells and inflammation
What are the secretory enzymes released by H. pylori?
Mucinase
Protease
Lipase
What is Peptic Ulcer Disease?
Deep lesion in mucosa of stomach or duodenem
What is peptic ulcer disease a complication of?
chronic gastritis
What is peptic ulcer disease most commonly associated with?
H. pylori infection
NSAIDs
Cigarette smoking
What are the clinical features of peptic ulcer disease?
Epigastric burning Iron Deficiency anemia Hemorrhage Perforation Nausea/Vomiting Bloating Belching Significant Weight Loss
What are complications of peptic ulcer disease?
Bleeding
Perforation
Obstruction
What causes antral gastritis?
H. pylori causing increased acid and decreased bicarbonate
What does antral gastritis cause?
antral/duodenem ulcers
What does H. pylori cause in the fundus/body?
gastric atrophy
What does gastric atrophy cause?
Intestinal metaplasia
What should be considered colon adenocarcinoma unless proven otherwise?
Iron deficiency anemia in post menopausal women or elderly men
What are the most common types of gastric polyps?
Inflammatory and Hyperplastic Polyps
What is the pathogenesis of inflammatory and hyperplastic polyps?
H. pylori causes chronic gastritis which leads to reactive hyperplasia which causes the polyps
What size of the polyp requires it to be resected and biopsied?
> 1.5 cm
What are 25% common gastric polyps and who do they most often occur in?
Fundic Gland Polyps
In younger people
What are fundic gland polyps most commonly associated with?
individuals with familial adenomatous polyposis (FAP)
What causes fundic gland polyps?
proton pump inhibitory therapy which causes increased gastrin and causes the gland to overgrow
What are the clinical features of fundic gland polyps?
They can be asymptomatic or associated with:
Nausea
Vomiting
Epigastric pain
What is the most common malignancy of the stomach?
Gastric adenocarcinoma
What are the two morphological types of gastric adenocarcinoma?
Intestinal type
Diffuse type
What does the intestinal type have?
bulky mass
What characterizes the diffuse type?
it spreads and invades wall of GI tract
What are the early symptoms of gastric adenocarcinoma?
Similar to Chronic Gastritis and peptic ulcer disease
What are the advanced symptoms of Gastric adenocarcinoma?
Weight Loss Anorexia Early Satiety Anemia Hemorrhage
What are the precursors to Gastric adenocarcinoma?
Gastric dysplasia
Adenomas
What mutations cause Gastric adenocarcinoma?
BRCA2
TP53
What are the clinical features associated with Intestinal Obstruction?
Abdominal pain Distinction Vomiting Constipation Hypovolemia Metabolic Acidosis
What is the most common cause of intestinal obstruction?
Adhesions
What is a hernia?
Any weakness or defect in the abdominal wall that permits a protrusion of a serosa-lined pouch of peritoneum called a hernia sac
What is a volvulus?
Twisting of bowel
What is intussesception?
Segment of the intestine telescopes into the immediately distal segment and is constricted by a wave of peristalsis
Who is intussesception most common in?
Children less than 2
What is a common cause of intestinal obstruction in pregnancy?
Volvulus
What is the most common cause of intestinal obstruction in places other than the US?
Hernia
What is the majority of the GI tract’s arterial supply?
Celiac
Superior Mesenteric
Inferior Mesenteric
What are the causes of Ischemic Bowl Disease?
Severe Atherosclerosis Aortic Aneurysm Hypercoagulable states Oral Contraceptive use Embolization Hypoperfusion
What is ischemic bowel disease?
Necrosis of the GI tract
What types of infarction occur in Ischemic bowl disease?
Mucosal
Mural
Transmural
Where does a mucosal infarction occur?
In the superficial layer
Where does the transmural infarction occur?
In the entire 4 layers
What is the phase 1 of Ischemic bowel disease?
Hypoxia injury
What is phase 2 of Ischemic bowel disease?
Reperfusion injury
What are the clinical features of ischemic bowel disease?
Sudden onset of cramping
Left lower abdominal pain
Desire to defecate
Bloody diarrhea
What is the cause of bloody diarrhea in ischemic bowel disease?
Shock and vascular collapse
When is ischemic bowel disease most common?
In those 70 years of age or older
What are the clinical features of Infectious Enterocolitis?
Diarrhea Abdominal Pain Urgency Perinatal discomfort Incontinence Hemorrhage
What is the major cause of death worldwide?
Infectious Enterocolitis
What is the cause of Infectious Enterocolitis?
E. Coli is most frequently responsible but etiology varies with age, nutrition, host immune status, and environmental influences
What are the common bacterial agents of Infectious Enterocolitis?
Cholera Campylobacter jejuni Shigella flexneri Salmonella typhoid/enteriditis/typhirmurium E. Coli C. Difficile
Where does cholera occur?
Where there is a natural disaster
How would a patient get cholera?
By drinking contaminated drinking water or contaminated food
What are the symptoms of cholera?
Watery, rice stool diarrhea at a rate of 1L/hour
Vomiting following an incubation of 1-5 days
What does cholera cause?
Dehydration Hypotension Muscular cramping Anura Shock Loss of consciousness Death
What is the pathogenesis behind cholera and its secretory diarrhea?
Cholera toxin increases adenylate cyclase which increases cAMP
CAMP increase opens a chloride channel with causes sodium and water to also leave the cell =
Water diarrhea
What bacteria causes Campylobacter Enterocolitis?
Campylobacter jejuni
What is Campylobacter jejuni?
Most common bacterial enteric pathogen in developed countries
What are the symptoms of Campylobacter Enterocolitis?
Traveler’s Diarrhea/Watery Diarrhea Dysentery Reactive arthritis Erythema Nodosum Guillain-Barré syndrome
What is Campylobacter Enterocolitis associated with?
Ingestion of improperly cooked chicken, unpasteurized milk or contaminated water
What are the virulence factors of Campylobacter jejuni?
Motility
Adherence
Toxin production
INvasion
Where does the bacteria proliferate?
In Lamina propia and mesenteric lymph nodes
How does C. Jejuni invade the bacteria?
1) adheres to host cell
2) F-actin and/or microtubules rearrange at this site causing engulfment and bacterial uptake
3) host cell signaling molecules and pathways like the intracellular survival in campylobacter containing vacuoles cause infection
What bacteria causes Shigellosis?
Shigella Flexneri
What is shigella flexneri?
Gram negative unencapsulated, non-motile, facultative anaerobes
What does Shigella flexneri secrete that causes the disease?
Shiga toxin (Stx)
What does shiga toxin cause?
Decreased protein synthesis
What is shigellosis the most common cause of?
Blood diarrhea (dysentery)
How is shigellosis transmitted?
Fecal-oral route or via contaminated water and food
Who is shigellosis the most common cause of death in?
In children less than 5
What are the clinical features of Shigellosis?
Incubation period - 1 week
Dysentery diarrhea
Fever
Abdominal Pain
How does Shigella invade and cause inflammation?
1) crosses epithelial barrier through M-cells where they encounter macrophages
2) Binding of lipoprotein to TLR2 in macrophages results in production of IL-1 and IL-8
3) IL-8 causes PMN transmigration
4) death of cells
What is the primary destructive force in Shigella infection?
PMNs
What is the function of PMNs?
Cause chloride secretion through generation of a precursor to the secretagogue adenosine
Also causes ulceration of epithelium resulting in decrease in absorptive surface and maximizing permeability
Which bacteria causes Salmonella exclusively in the GI tract only?
S. Enteriditis
S. Typhimurium
How many cases of Salmonellsis are there per year and what does it cause?
More than 1 million cases
FOOD POISONING
Who is salmonellosis most common in?
Young children and older adults
When is the peak incidence of salmonellosis?
Summer and fall
What are the clinical features of Salmonella?
Inflammatory Diarrhea
Fever resolving in 2 days
How long does the diarrhea persist for with Salmonellisi?
Week or more with organisms being present in stool for several weeks
What does the bacteria possess that cause Salmonellisis?
Virulence genes that encode a type III secretion system
What is the Type 3 secretion system capable of?
Transferring bacterial proteins into M cells and enterocytes
What bacteria causes typhoid fever?
S. Typhi
What are the two things that can form due to S. Typhi?
Typhoid nodules
Typhoid ulcers
Where do typhoid nodules occur?
Liver
Bone marrow
Lymph node
What are the clinical features of Typhoid fever?
Anorexia Abdominal Pain Bloating Nausea/Vomiting Bloody diarrhea followed by short asymptomatic phase Rose spots Extraintestinal complications
What is E.coli?
Gram negative bacilli that colonize the healthy GI tract
Mostly nonpathogenic but can cause human disease
What are the 4 strains of E. Coli?
Enterohemorrhagic
Enterotoxigenic
Enteroinvasive
Enteropathogenic
What is the most dangerous form of enterohemorrhagic e. Coli?
O157H7
What does enterohemorrhagic E. Coli secrete?
Shigella like toxin that inactivates ribosomes
What is enterohemorrhagic E. Coli associated with?
Consumption of inadequately cooked ground beef
What are the clinical features of enterohemorrhagic E. Coli?
Hemolytic Uremic Syndrome
What does hemolytic uremic syndrome cause?
Lysis of RBS’s
Renal Failure
Thrombocytopenia
What does enterotoxigenic E. Coli secrete?
Heat stable toxin (ST)
Heat-labeled toxin (LT)
What is enterotoxigenic E. Coli similar to?
Cholera
What does enterotoxigenic E. Coli cause?
Increase in adenylate cyclase/cAMP causing increased secretions
Secretory, non-inflammatory diarrhea
Shock in severe cases
How is Enteroinvasive E. Coli transmitted?
Food
Water
Person to person contact
What is so different about enteroinvasive E. Coli compared to the other strains of E. Coli?
It is the only one that invades the epithelial host cells and doesn’t produce toxins
What does Enteroinvasive E. Coli cause?
Dysentery
What does enteropathogenic E. Coli cause?
Endemic diarrhea in children under 2
How does enteropathogenic E. Coli work?
Attaches to epithelium and destroys microvilli in small intestine
What is osmotic diarrhea caused by?
Failure to absorb food
What is Pseudomembranoous Colitis caused by?
C. Difficile
What are the risk factors for Pseudomembrance COlitis?
Advanced age
Hospitalization
Antibiotic treatment
What are the clinical features of Pseudomembranous COlitis?
Fever Leukocytosis Abdominal Pain Cramps Watery Diarrhea Dehydration Protein loss/hypoalbuminemia
What is the major challenge with Pseudomembranous colitis?
Recurrent infection
What is the mnemonic for Viral Gastroenteritis viruses?
CANCAR
Corona virus Adenovirus NOROVIRUS Calcivirus Astrovirus ROTAVIRUS
Who are most vulnerable to get Viral Gastroenteritis?
Children between 6-24 months
Where are rotavirus outbreaks most common?
In hospital and daycare centers
Infection spreads quickly
How many viral particles are required to cause Viral Gastroenteritis?
10 viral particles
What does viral gastroenteritis typically cause?
Secretory and osmotic diarrhea
What is the pathogenesis of Viral Gastroenteritis, particularly that caused by Rotavirus?
NSP-4 acts like a viral endotoxin and causes an increase in calcium inside the cell
This stimulates the enteric nervous system and activation of epithelial cell chloride secretion
This causes cell death and a reduction in absorptive surface of the intestine
What parasites cause Parasitic Enterocolitis?
Entamoeba hystolytica Giardia Lamblia Giant roundworm - ascaris lumbricoides Threadworm - stronglyoides Hookworm - Necator duodenale and ancylostoma duodenale Pinworm - enterobius vermicularis Whip worm - trichuris trichura Cryptosporidium
What is inflammatory bowel disease?
Inappropriate mucosal immune activation
What are the two types of Inflammatory Bowel Disease?
Crohn Disease
Ulcerative Colitis
What are the clinical features of Crohn Disease?
extremely variable
Intermittent Mild Diarrhea Fever Abdominal Pain Iron deficiency anemia Serum protein loss and hypoalbuminemia Malabsorption of Vitamin B12 and bile salts Fibrosing strictures of the terminal ileum Fistulae
What are the clinical features of Ulcerative Colitis?
Bloody Diarrhea with stringy, Mucosa material
Lower abdominal pain
Cramps that are temporarily relieved by defecation
What are the trigger factors for Ulcerative Colitis?
Infectious enteritis
Stress
Where does Crohn’s disease occur?
Ileum and colon
What is the distribution of Crohn disease?
Skip lesions
What is the type of inflammation with Crohn’s disease?
Transmural inflammation
What type of ulcers are there in Crohn’s disease?
Deep, knife like
Where does Ulcerative Colitis occur?
colon only
What is the distribution of Ulcerative Colitis?
Diffuse
What is the type of inflammation of Ulcerative colitis?
Limited to mucosa inflammation
What type of ulcers occur in Ulcerative Colitis?
Superficial, broad-based