Gastrointestinal System Flashcards
diseases of the GI tract can be classified as:
- developmental disorders
- inflammatory diseases
- functional disorders
- circulatory disturbances
- neoplastic diseases
what are the pathologies of the esophagus
- hiatial hernia
- reflux esophagus
- achalasia
- esophageal varices
what are the conditions of the stomach
- acute gastritis
- chronic gastritis
- peptic ulcer disease
- stomach cancer
what are the conditions f the small intenstine
- meckel diverticulum
- bowel obstruction
- herniation
- adhesions
- intussesception
- volvulus
- adenocarcinoma
- carcinoid tumor
what are the conditions of the large intestine
- pseudomembranenous colitis
- diverticulosis
- chron disease
- ulcerative colitis
- adenomatous polyps
- colon cancer
what are the layers of the GI system
- mucosa
- submucosa
- muscularis
what makes up the mucosa in the GI system
- epithelium
- lamina propria
- muscularis mucosa
what are the types of muscularic propria
- circumferential
- longitudinal
what is dysphagia
difficulty swallowing
what is hematesis
vomiting of fresh red blood
what is hematochezia
bright red blood in stool
what is melena
balck tarry feces
what is diarrhea
frequent, loose, watery bowel movements
what is constipation
hard feces that are difficult to eliminate
what is odynophagia
painful swallowing
what is gastroenterology
a subspecialty of internal medicien
what is esophagogastroduodenoscopy
upper GI endoscopy
what is a colonoscopy
lower GI endoscopy
what is odynophagia
pain on swallowing
what is heartburn
a burning behind the sternum - GERD
what are clinical symptoms and signs of esophageal disease
dysphagia
- odynophagia
- heartburn
- acid regurgitation into mouth
what is achalasia
- a functional motor disorder
- dysfunction of ganglion cells of myenteric plexus (auerbach plexus) prevents proper relaxation of lower esophageal sphincter- a motility disorder
what are the symptoms in achalasia
- dysphagia
- regurgitation
- halitosis
- proximal dilation
describe plummer- vinson symdrom (paterson- kelly syndrome)
- scandanavian , norther european women
- severe iron deficiency anemia
- mucosal atrophy - atrophic glossitis
- esophageal webs- dysphagia
- increased risk for squamous cell carcinoma in esophagus, oropharynx and posterior oral cavity
what are esophageal varies caused by
portal hypertension produced venous dilation
describe rupture of esophageal varices
- rupture leads to hematesis and massive upper GI bleed
- rupture of a varix is associated with high mortality
- rupture of a varix accounts for half of the deaths in advanced cirrhosis
what are mallory weiss syndrome seen in and what is it
- seen in chronic alcoholics, where violent retching causes esophageal lacerations and hemorrhage
what is a hiatal hernia
- diaphragmatic hernia- widended diaphragmatic hiatus allows protrusion of the stomach through the diaphragm
- gastroesophageal junction pulled into thorax
what is barrett esophagus
- gastric metaplasia of lower esophageal mucosa- columnar epithelium replaces stratified squamous epithelium
- odynophagia, ulceration and hemorrhage
- risk of developing adenocarcinoma
describe esophageal canccer
- squamous cell carcinoma
- adenocarcinoma- barret esophagus
- dysphagia due to narrowing of lumen or interference with peristalsis
describe esophageal squamous cell carcinoma
- older adults, geographical variation, poor prognosis
- most common world wide but adenocarcinoma of esophagus is more common in US
- most common in middle third
- alcohol and tobacco, plummer vinson syndrome, diet influence incidence
describe esophageal adenocarcinoma
- lower segment
- barrett esophagus is a risk factor
- more common than squamous carcinoma in US
what are the epithelial cells of the stomach and what do they do and where are they found
- mucous cells- secrete mucous, in cardia
- parietal cells- located in body, secretes hydrochloric acid, and intrinsic factor
- chief cells- located in body, pepsin
- endocrine cells- G cells- gastrin
describe gastritis
-inflammation of the gastric mucosa
- acute gastritis- erosive, due to irritants and NSAIDSs
- chronic gastritis- erosive or non erosive- infectious or autoimmune
describe acute erosive gastritis
- epigastric burning, pain , nausea , vomiting
- shallow erosions
- aspirin, NSAIDs, alcohol, stress, shock , sepsis
- one of the major causes of hematemesis in alcoholics
describe chornic gastritis
- infectious- the most common form of chronic gastritis is due to infection by helicobacter pyloris
- autoimmune- autoantibodies directed against parietal cells
what do H pyloris cause
- peptic ulcer disease
- adenocarcinoma
- MALT lymphoma
describe H pylori
- gram negative s-shaped rods
- biopsy and silver stain
- urea breath test
- antibody test for H pylori
describe autoimmune gastritis
- autoantibodies against gastric parietal cells
- gastric mucosal atrophy
- no IF, low serum vitamin B12, pernicious anemia
describe gastric stress ulcers
- deeper than erosions may extend to muscularis
- severe stress- ICU patietns - shock, trauma, burns, sepsis
describe peptic ulcer ddisease
most peptic ulcers are generally solitary lesions
- most occur in the duodenum - 98% are located in duodenum or stomach
what are characteristics of peptic ulcers
- sharply demarcated ulcer with a clean, smooth base
- chronic lesions may exhibit puckering due to fibrosis
what is the clinical course pf peptic ulcer disease
- acute/chronic blood loss
- nausea, vomiting, hematemesis, melena
- perforation- major cause of death in PUD
what does immediate pain in peptic ulcer mean
gastric ulcer
what does delayed pain in peptic ulcer mean
duodenal ulcer
what is etiology of peptic ulcers
- mutlifactorial disease, decreased mucosal resistance
- infection by H pyloris
- drugs- aspiriin - NSAIDs
- neuroendocrine- hormonal hypersecretion syndromes
- cushing syndromes- corticosteroids
- zollinger ellision syndrome- gastrin
what are the complications of peptic ulcer disaese
- minor hemorrhage- melena, iron defiency, anemia
- major hemorrhage- hematemesis
- perforation- peritonitis
- stenosis and obstruciton
- penetration into pancreas
describe zollinger ellison syndrom
- gastrin secretion tumor in pancreas of duodenum ( gastrinoma
- hypergastrinemia causes hypersecretion of gastric acid
- severe peptic ulcer disease with multiple ulcers in unusual locations
describe gastric adenocarcinoma
- older individuals- poor prognosis
- smoked fish - nitrosamines
- predisposition to gastric cancer
- h. pylori infection
- chronic atrophic gastritis
- gastric adenomatous polyps
- less curve of antro- pyloric region
what are the types of gastric adenocarcinoma and describe each
- intestinal type- bulky tumors composed of glandular structures
- diffuse type- infiltrative growth of poorly differentiated cells (linitis plastica)
what is a krukenberg tumor
- metastatic adenocarcinoma to ovaries
- bilateral ovarial metastases
- frequently of gastric origin- mucus producing cells
describe gastrointestinal tract lymphoma
- non- hodgkin lymphoma
- primary lymphomas- MALT-omas and other NHLs
- secondary lymphomas- extranodal spread
what is a gastric MALT lymphoma
- stomach- most common site for extranodal lymphomas
- MALT lymphomas- B cell lymphomas of mucosa associated lymphoid tissue
- associated with helicobacter pylori infection - may regress with H pylori treatment
describe meckel diverticulum
- developmental defect of ileum- a blind pouch containing all layers
- left- sides appendix- may produce symptoms similar to appendicitis
what are the types of bowel obstruction
- herniation
- intussuscpetion
- adhesions
- volvulus
what are herniations
weakness in peritoneum
where can herniations occur
- inguinal
- femoral
- umbilicus
- -incisional
what are adhesions
- fibrotic bridges of peritoneum
- may trap and link bowel segments
- they are usually sequelae of prior surgery or infection
what is intussusception
- small intestine invaginates into itself- intussusceptum becomes necrosis unless everted
- small pedunculated tumors carries by peristalsis may pull forward the loop to which it is attached
what is volvulus
- rotation of a loop of intestine about its own mesenteric root
- most common in small intestine and sigmoid colon
- volvulus undergoes necrosis
what is the prevalence of adenocarcinoma of small intestine
rare
describe carcinoid tumor
- a low grade malignancy of neuroendocrine cells, appearing as mucosal nodules
- may occur throughout gastrointestinal tract but are most common in appendix
- may produce hormones such as serotonin
describe carcinoid syndrom
- caused by a serotonin- producing carcinoid tumor that is asymptomatic until metastasis to the liver
- the serotonin that is no longer metabolized by the liver causes cramping, diarrhea, flushing and bronchospasm
describe the colon
- enteric nervous system- myenteric (auerbach) and submucosal plexus (Meissner)
- colonized by non pathogenic strains of bacteria
what is hirschprung disease- congenital megacolon
- developmental defect of enteric nervous system- agangliosis of terminal colon (myenteric plexus)
- chronic constipation proximal dilation
- resection of aganlionic segment
what is the characteristic histology of the large intestine
crypts
what is the characteristic histology of the small intestine
villi
what is diverticulosis
- consist of out- pouchings of mucosa and submucosa through muscular layer of colon
- associate with a low bulk diet, straining during defecation
- may become inflamed- diverticultis
what are the types of intestinal polyps and describe each
- neoplastic polyps (adematous polyps, adenomas): tubular adenoma and villous adenoma
- non-neoplastic polyps: hyperplastic polyp- most common
- hamartomatous polyp- Peutz- Jeghers Syndrome
describe hyperplastic polyp
- non-neoplastic hyperplasia of epithelium, most common
- not pre- malignant
describe hamartomatous polyp
- large- pedunculated polyp, consisting of all layers of the. mucosa
- may be associated with peutz- jeghers syndrome
- risk for intussusception
- no malignant change
describe Peutz- Jegher Syndrome
- autosomal dominant
- pigmented. macules of oral mucosa and perioral skin
- hamartomatous polyps of bowerl
- increased risk for adenocarcinoma outside GI tract- pancreas, breast, lung, ovary, uterus
describe adematous polyps- adenomas- neoplastic polyps
- tubular adenomas- tubular glands, frequently pedunculated
- villous adenomas- villous projections, frequently sessile
describe a tubular adenoma
- most common neoplastic polyp
- less than 5% malignant transformatino
- endoscopic polypectomy curative
describe villous adenoma
- least common neoplastic pulp
- 50% malignant transformation
- endoscopic removal often not possible
describe colonic adenocarcinoma
- third most common cause of cancer death - lung, breast/prostate, colon
- older adults, unless predisposing condition (ulcerative colitis, hereditary colon cancer syndrome, gardner syndrome)
- dietary risk factors- high caloric intake, high fat, red meat, high refined carbohydrates, low fiber
adenoma carcinoma sequence:
- normal colon -> mucosa at risk -> adenomas -> carcnoma
in adenoma carcinomas there are accumulation os mutations in:
tumor supressor genes and proto oncogenes
describe colonic adenocarcinoma
- sigmoid colon most common site
- left side- circumferential, napking- ring lesion producing narrowing of lumen
- right side- exophystic, polypoid, crater- like ulcerations with rolled borders
what is the most prognostic indicator for colon cancer
stage
what is hereditary colonic cancer syndromes
- autsomal dominant
- familial adenomatous polyposis cali (FAP) - multiple tubular adenomas, 100% malignant transformation
- gardner syndrome- a variant of FAP with multiple supernumerary teeth, jaw bone densities, mulitple osteomas, fibromatosis, epidermal inclusion cysts
- hereditary non polyposis colorectal cancer (HNPCC)- colonic cancer unrealted to adenomas: increased risk of endometrial and ovarian cancers
describe IBS
- two chronic relapsing inflammatory disorders of unknwon etiology
- crohn disease
- ulcerative colitis
- exaggerated and unregulated local immune response in genetically susceptable individuals
describe chron disease
-any level of GI tract, outh to anus, most often distal ileum and colon
- transmural inflammation, thickened intestinal wall
- sarcoid like non- caseating granulomas
- pain, diarrhea, fissure and fistula formation
what is a fistula
an abnormal channel between hollow orgnas or between a hollow organ and the skin surface
what are oral manifestations of crohn disease
- apthous like lesions
- granulomatous nodules
- malabsorption vitamin K dependent clotting factor deficiency, bleeding diathesis
describe ulcerative colitis
- chronic inflammatory disease with increased risk of malignancy
- thinning of intestinal wall, limited to colon and rectum
- relapsing diarrhea and pain
where is inflammation limited to in ulcerative colitis
mucosa- not transmural
what are crypt abscesses and what disease are they seen with
- accumulation of neutrophils within colinic crypts are signs of active inflammation
- ulcerative colitis
what are pseudopolyps and what disease are these seen with
remnants of colonic mucosa surrounded by ulceration
what is pyostomatitis vegetans
- oral lesions of ulcerative colitis
- small, yellow superficial pustules
what are the differences between crohn disease and ulcerative colitis
- crohn disease skips lesions
- ulcerative colitis is continuous colinic involvement beginning in rectum
what is the region of crohn disease? ulcerative colitis?
- ileum and colon
- colon only
what is the wall of crohn disease? ulcerative colitis?
- thickened
- thin
what is the inflammation of crohn disease? ulcerative colitis?
- transmural
- mucosa
what is the ulcers of crohn disease? ulcerative colitis?
- deep, linear
- superficial
what is the granulomas of crohn disease? ulcerative colitis?
- yes
- no
are there fistulae in crohn disease? ulcerative colitis?
- yes
- no
is there malabsorption in crohn disease? ulcerative colitis?
- yes
- no
is there malignant risk in crohn disease? ulcerative colitis?
- low
- high
describe appendicitis
- an acute bacterial infection of appendix
- complications may include rupture and peritonitis
what are the types of appendicits- obstruction of lumen
- fecalith- inspissated fecal material
- reactive lymphoid hyperplasia- resopnse to viral infection
- neoplasm- carcinoid tumor
describe acute appendicitis
- acute inflamamtion, mucosal ulceration
- transmural inflammation
- serositis
- peritonitis
- right lower quadrant pain, rebound tenderness
- leukocytosis, fever, nausea, vomiting
what are hemorrhoids
- varicose dilation of hemorroidal venous plexus at anorectal junction
- increased venous pressure may be associated with pregnancy, chronic constipation, portal HTN
