GI 1.1 Final

oral cavity epithelium?

• masticatory mucosa → keratinizing strat. squam.

• lining mucosa → NK strat. squam.

• specialized mucosa → papillae + taste buds

• drug absorption → sublingual route bypasses portal circ.

extrinsic and intrinsic tongue muscles? sensory nerves?

• genioglossus (protrude), hyoglossus (depress), styloglossus (retrude), palatoglossus (elevate post. tongue; ONLY CNX)

• shape change for speech/swallow (CNXII for everything)

• ant. 2/3 sensation (lingual) vs taste (chorda tympani), post. 1/3 sensation + taste (CNIX), epiglottis (int. laryngeal)

blood supply of tongue? lymphatics of tongue?

• lingual artery (ECA); venous drainage to int. jugular

• tip (submental), sides (submandibular) + deep cervical), post. (deep cervical)

lingual papillae? taste buds?

• filiform (center ant. 2/3; w/o buds), fungiform (margins), circumvallate (V shape ant. to term. sulcus), foliate (lat.)

• neuroepithelial (sensory; synapse w/ CN VII, IX,X), supporting (microvilli, no synapse), basal (stem cells)

teeth tissues? salivary glands?

• enamel (ameloblasts), dentin (odontoblasts → neural crest), cementum (covers root)

  • root nerve supply → inf. alveolar nerve (CN V3)

• parotid (serous only), submandibular (mixed, mostly serous), sublingual (mixed, mostly mucus)

pharyngeal muscles? function?

• circular (constrictor) → sup., middle, inf. (UES = cricopharyngeus)

• longitudinal → stylopharyngeus (CNIX), palatopharyngeus, salpingopharyngeus (CNX)

• elevate larynx, shorten pharynx during swallow/speak

GI histology?

• mucosa → epi., LP, musc. muc.

• submucosa → meissner plexus (sec.), galnds

• muscularis → auerbach plexus (motility); inner circ., outer long.

• serosa/adventitia → serosa = intraperitoneal; adventitia = retroperitoneal

cells/glands throughout GIT?

• esophagus → mucous glands, adventitia

• stomach → cardiac (mucus), fundic (parietal, chief, enteroendocrine), pyloric (G cell)

• duodenum → villi, crypts, brunner glands

• jejunum → villi, crypts, plicae circularae

• ileum → goblet cells, peyer’s patches

• colon → crypts, goblet cells NO villi

• anus → transition to strat. squam.

small intestine segments? structure?

• duodenum → sup., desc., hori., asc.; retroperitoneal EXCEPT prox. 1st + distal 4th

  • major duodenal papilla → opening of hepatopancreatic ampulla (main pancreatic + bile duct)

  • minor duodenal papilla → acc. pancreatic duct

• jejunum → thick wall, fewer arterial arcades, long vasa recta, prom. circ. fold

• ileum → thinner walls, more arcades, short vasa recta, peyer’s patches (lymphoid agg.)

large intestine segments? structure? appendix?

• cecum → asc. → tran. → desc. → sigmoid → rectum → anal canal

• teniae coli (3 muscle bands), haustra (sacculation of colon wall), epiploic appendages (fat filled peritoneal pouch), ileocecal valve (mucosal fold, min. anti-reflux role)

• appendix → lymphoid rich, variable position; mcburney’s point = T10 referred pain

rectum location? structure?

• begins @ S3, ends @ pelvic diaphragm

• rectal ampulla → dilated lower portion

• puborectalis sling → forms anorectal angle for continence

• transverse folds → perm. mucosal folds

viridans streptococci class? plating? symptoms?

• bacteria catalase (-) anaerobes

• gram (+), a, B, or y-hemolytic (green on blood agar)

  • main micro in oropharynx, GIT

• dental caries (via sugar fermentation) + endocarditis

  • LA → low pH (kills microbiota + favors acid res.) → low O2 (anaerobe bind) → polysaccharide = biofilm/plaque → demineralization/lesion

actinomyces israelii class? plating? symptoms?

• bacteria catalase (-) anaerobes

• gram (+), sulfur granules, filamentous

  • via poor oral hygiene or trauma/surgery

• usually cervicofacial → lumpy jaw

porphyromonas gingivalis class? plating? symptoms?

• bacteria catalase (-) anaerobes

• gram (-), black on blood agar

  • uses fimbriae as VF

• gingivitis, periodontitis, oral abscesses

fusobacterium necrophorum class? plating? symptoms?

• bacteria catalase (-) anaerobe

• gram (-)

  • enters jugular vein (Dx w/ neck CT) → systemic spread (esp. lungs); sore throat

• suppurative jugular thrombophlebitis (lemierre)

candida albicans class? plating? symptoms?

• fungi

• prod. buds/blastoconidia; smooth white, fuzzy, creamy colonies (pseudohyphae)

• oral thrush (scrapable), yeast infection; HIV pts

HSV1 class? features? symptoms?

• herpesviridae; dsDNA → infect + replicate in mucoepithelial cells

• multinucleated giant cells (syncytia) → tzanck smear; cowdrey bodies

  • latent in trigeminal ganglia

• oral (lips, tongue) vascular lesions (recurrent), can progress to encephalitis; gingival ulcer, swollen gums, cervical LAD

EBV class? features? symptoms?

• herpesviridae; dsDNA → uses C3d receptor (CR2, CD21)

• heterophile antibody-positive infectious mono → stimulates B cell growth; can remain dormant/latent

• oral hairy leukoplakia (balloon cells, hyperkeratosis, lat. tongue, non-scrapable)

HPV class? features? symptoms?

• papillomaviridae; circular dsDNA, naked

• infects host basal epithelial cells → proliferate/grow → stratum spinosum thicken → wart condyloma, papilloma (benign or malignant)

• laryngeal cancer, squamous papilloma, nonkeratinizing SCC

mumps class? features? symptoms?

• paramyxoviridae; (-) RNA

• spreads/mulitplies in local lymphoid tissues + reticuloendothelial cells

• meningitis, parotitis, orchitis in unvaccinated child

aphthous ulcer symptoms? histo/micro?

• inflammatory; canker sore

  • associated w/ stress, IBD, behcet, celiac, HIV

  • painful, shallow, recurrent mucosal ulcer

• mononuclear, neutrophilic infiltrate

irritation fibroma symptoms? histo/micro?

• inflammatory; trauma-induced @ bite line, gingiva → buccal submucosal nodular mass

• fibrous stroma

pyogenic granuloma (lobular capillary hemangioma) symptoms? histo/micro?

• inflammatory; vascular proliferation w/ granulation tissue tissue rxn (rapid growth) → red/ulcerated, pregnancy associated

  • peripheral ossifying fibroma → gingival growth from periodontal lig. following pyogenic granuloma

• polyploid lesion resembling mushroom @ skin surface

peripheral giant cell granuloma symptoms? histo/micro?

• inflammatory; reactive gingival lesion → fibroangiomatous stroma

  • DDxs = brown tumor, giant cell tumor

• fibrovascular stroma w/ multinucleated giant cells; intact overlying gingival squamous mucosa

squamous papilla features? histo/micro?

• neoplastic (most common benign oral cavity neoplasm) via HPV

• exophytic lesion w/ branching squamous epithelium + fibrovascular cores

  • cauliflower, skin/pearly/grey warts

• squamous proliferation w/o dysplasia, keratosis, viral cytopathic change

hairy leukoplakia symptoms? histo/micro?

• proliferative; white, fluffy, non-scrapable patch on lateral tongue

  • low malignancy risk

  • more common in EBV, immunocompromised

• balloon cell, hyperkeratosis (expanded corneus layer w/ retained nuclei), acanthosis (expanded stratum spinosum, but orderly)

erythroplakia symptoms? histo/micro?

• red, velvety, non-scrapable patch

  • w/ severe dysplasia → loss of polarity, freq. mitosis, coarse chromatin

  • carcinoma in situ, minimally invasive CA

• high malignancy risk

squamous cell carcinoma (SCC) symptoms? histo/micro?

• ulcerated, indurated lesions w/ irregular borders

  • associated w/ HPV 16/18, tobacco, alcohol, betel quid (asia), sunlight (lip), idiopathic (YA)

  • better prognosis w/ p16 IHC+

  • leukoplakia (keratin pearl, hyper keratinization) + erythroplakia = precursors

• keratinizing or non-keratinizing (HPV), fibrovascular cores, NO dysplasia

odontogenic cysts? tumors?

• dentigerous cyst → crown of impacted/unerupted tooth (fluid accumulates btwn tooth + dental follicle) = unilocular cyst, NK squamous w/ chronic inflammation

• radicular cyst → apex of tooth (long pulpitis = necrosis) = granulation + epithlialization

• keratocystic tumor → well-defined unilocular to multilocular = keratinized SSE w/ prom. basal layer + NO RETE ridge

xerostomia features? sialadenitis features?

• via sjogren, meds, radiation → inc. risk of candidiasis + caries

• salivary gland inflammation (related to mumps/autoimmune) → acinar atrophy w/ fibrosis

mucocele features? ranula features?

• trauma induced duct rupture → pseudocyst lined w/ inflammatory granulation or fibrous CT (recurs if incomplete excision)

  • bluish hue (may contain mucin + MQ)

• sublingual (floor of mouth) duct cyst (recurs if incomplete excision)

  • may plunge into mylohyoid

pleomorphic adenoma features? warthin tumor features? mucoepidermoid carcinoma features?

• most common (benign), @ parotid gland (recurs if not entirely excised) → epithelial + mesenchymal + cartilaginous

• @ parotid gland, papillary cystadenoma lymphomatosum → risk w/ smokers; epithelial + lymphoid stroma

• most common (malignant), mucus filled vacuoles → mucinous + squamous cells; grade dependent

esophagus tissue? muscle? innervation?

• stratified squamous epithelium → transition to columnar @ GE jxn

  • barretts esophagus → metaplasia of squamous to columnar w/ goblet cells → low (inc. mit, basal nuclei w/ mild atypia) vs high grade dysplasia (p53 mut, loss of polarity, mit., crowded glands + lose LP) → adenocarcinoma

• muscle → upper skeletal, middle mixed, lower smooth

• innervation → auerbach (myenteric) + meissner (submucosal) plexus

esophageal atresia?

• congenital mechanical esophageal obstructions

• segment of esophagus doesn’t develop near tracheal bifurcation w/ fistula (UE or LE connect to bronchus/trachea)

• nonbilious emesis, choke, cough @ initial feed (progressive dysphagia)

  • TE fistula = aspiration, suffocation, pneumonia

acquired esophageal mechanical obstruction?

• benign esophageal stenosis → fibrous thicken = progressive dysphagia (solid → liquid)

• esophageal webs → mucosal protrusion into lumen @ upper esophagus = poorly chewed, non progressive dysphagia

• shatzki ring → thin mucosal ring @ GE jxn via reflux/inflammation = solid food dysphagia

  • steakhouse syndrome/impaction; Tx via dilation

plummer-vinson syndrome cause? features? risk?

• mechanical obstruction

• Fe def. anemia (ox. stress + DNA damage = epi. injury) + prox. esophageal webs (squamous mucosal protrusion into lumen)

• dysphagia (solids > liquids) w/ hypochromic anemia in middle aged women

• risk for SCC of esophagus + pharynx

nutcracker esophagus? corkscrew esophagus?

• functional obstruction, measure pressure + muscle w/ manometry

• high amplitude, hypercontractile sequential @ distal esophagus = dysphagia + chest pain

  • barium = alt. narrow + distended seg.

• high amplitude, uncoordinated + simultaneous/diffuse contraction @ mid + distal esophagus = dysphagia + chest pain

  • Dx w/ barium swallow; Tx w/ CCBs, botox, myotomy

achalasia cause? features? symptoms?

• functional obstruction; neurodegeneration of submucosa myenteric plexus → impaired LES relaxation + impaired peristalsis = food build up/dilation

  • 1= degeneration of NO neurons; 2= chagas/protozoal tyrpanosoma cruzi damage plexus

  • DM, malignancy

• dysphagia (solid + liquid), regurgitation, chest pain, weight loss

  • bird beak sign/megaesophagus

esophageal diverticula structures? formation? types? symptoms?

• epithelial lined mucosal pouch protrude from esophageal lumen

• pulsion/false → inc. intraluminal pressure via hypercontractile or LES dysfxn = mucosa + submucosa herniates through muscle (zenker, epiphrenic)

• traction/true → ext. pulling via adj. inflammation fibrotic adhesion (gran. lymph.) = fibrosis pulls on all wall layers (midesophageal)

• = regurgitation of undigested food, halitosis, aspiration

pharyngoesophageal diverticulum (zenker)? midesophageal diverticulum? epiphrenic diverticulum?

• above UES spasm (cricopharyngeal) after swallow → inc. pressure @ distal pharynx → hypopharyngeal herniation @ killians triangle = halitosis, int. dysphagia

• true; adhesion btwn inflamed mediastinal LN (via TB, histo) + esophagus → pulls all layers (true)

• distal 10 cm/above LES= motor abnormalities (achalasia, hypertensive LES, spasm)

hiatal hernia types?

• sliding (common) → GE jxn + gastric cardia up thru diaphragm = GE reflux

• paraoesophageal → stomach pouch protrudes through esophageal hiatus adj. to GE jxn (below diaphragm) = more risks

esophageal lacerations causes? types?

• via retching, alcohol, inc. pressure (cough, abdominal strain)

• mallory-weiss → longitudinal @ GEJ, mucosa + submucosa = hematemesis, melena

• boerhaave → transmural w/ perforation, all layers = mediastinitis, pneumothorax, pneumomediastinum (crunching/hamman sign), pleural effusion

  • surgical intervention

esophagitis causes?

• chemical → caustics, alcohol, hot liquid, smoking; necrosis + neutrophils

• infectious → HSV (cowdry-A), CMV, candida; ulcer, inclusion, pseudomembranes

• GERD (most common) → LES relaxation/incompetence via inc. intra abd. pressure, inc. gastric vol., dec. distance, spice; multinucleate squamous cell, elongated LP papillae, basal cell hyperplasia, eosinophilia

  • = barrett’s esophagus (patchy red, velvet mucosa w/ columnar + goblet cells above GEJ)

• eosinophilic → allergy/immune-med.; >15 eosinophils/HPF, stacked circular rings/furrows/“feline esophagus”

esophageal adenocarcinoma risk factors? features? molecular?

• presents late w/ prog. dysphagia, weight loss, pain, hematemesis

• GERD, barretts, obesity/high red meat, tobacco/radiation, prolonged proton pump inhibitors

• lower 1/3 w/ gastric cardia; nodular mass/patch, poorly diff. glandular cells w/ mucin prod. (ulcerative forms)

• tumor suppressor mut. (TP53, CDKN2A =p16/19), proto-oncogene (MET, ERBB2)

esophageal squamous cell carcinoma (ESCC) risk factors? features? molecular?

• most common esophageal cancer; presents late w/ prog. dysphagia, weight loss, pain, hematemesis

• alcohol, tobacco, lye ingestion/diet, hot beverage, plummer-vinson, HPV, low SES (irritants)

• middle 1/3 w/ small white plaque; invades SM + ME, tumor cells in cords + nests (keratin pearls)

• tumor suppressor mut. (TP53, CDH1, NOTCH1/3), proto-oncogene over express (EGFR, cyclin D1, RAS/AKT)

• = hoarse voice (recurrent laryngeal nerve) + cough (trachea)

gastric anatomy + cells?

• mucosa (gastric pits + glands), SM, M, S

• cardia (GEJ) → mucin cells (protective mucus)

• fundus/body (above GEJ + middle w/ oxyntic gland) → parietal (HCI), chief (pepsinogen), ECL (histamine)

• antrum/pylorus (distal 1/3 + duodenal jxn w/ pyloric gland) → G cell (gastrin), D cell (somatostatin)

acute gastritis features? cause? symptoms?

• inflammation + neutrophil infiltration

  • edema, hemorrhage, erosion

• via direct damage, NSAID (inhibit COX → dec. PG), H. pylori/uremia, aging/impaired renewal

• asymptomatic w/ epigastric pain, nausea, vomit

chronic gastritis features? types cause, features?

• w/ lymphocytes + plasma cells; nausea, upper abdominal pain sometimes vomit

• autoimmune atrophic @ body-fundus → parietal cell Ab (hypochlorhydria + hypergastrinemia) + intrinsic factor Ab (dec. Vit B = pernicious anemia)

  • oxyntic gland flat w/ loss of rugal fold; endo hyperplasia, metaplasia w/ goblet cell (GACA), NEN

• H. pylori @ antrum but spreads (common) → inc. HCl sec. (destroys parietal cells = ““ + possible lymphoid agg.)

  • w/ flagella, urease, adhesins, CagA, VacA

  • peptic ulcer, MALToma; Dx w/ biopsy (anti-Ab), urease, PCT (DNA)

• mixed gastritis

peptic ulcer disease (PUD) cause? features? symptoms? types?

• H. pylori, NSAIDs, stress, trauma, ZES (inc. gastrin)

• early (fibrin, necrosis, inflammation, granulation) vs chronic (scarring + stenosis)

• nausea, vomit, bloat → melena, hematemesis, perforation, nocturnal pain

• gastric (punched-out lesion w/ clean base in lesser curvature; pain worse w/ eating + weight loss) OR duodenal (pain relieved w/ eating + weight gain, solitary morph.)

• Tx w/ H. pylori+ (triple/quad) + H. pylori- (PPI)

hypertrophic gastropathies types?

• menetrier = TGF-a → mucous cell hyperplasia (adenocarcinoma risk), protein loss, enlarged rugal folds

• zollinger-ellison = gastrinoma → inc. HCL (hyperchlorhydria), PUD, parietal hyperplasia (adenocarcinoma risk)

gastric adenocarcinoma features? symptoms? metastasis?

• poorly diff., large ulcers w/ heaped up rolled margins

• epigastric pain, weight loss, early satiety, virchow node, sister mary joseph nodule, krukenberg tumor

• liver, peritoneum, lung, bone

types of gastric adenocarcinoma?

• ulcerative = H. pylori, salt, PAHs- smoking → flat necrotic base

• polypoid = HER2, RAS → cauliflower, papillary

• scirrhous = CDH1 mut. → linitis plastica, signet ring

• colloid = PAS+ → mucinous

gastric lymphoma (MALT) cause? features?

• translocation → t(11;18), t(1;14), t(14;18)

• NF-kB act.

• CD19, 20, 43(+) & CD5,10(-)

gastric neuroendocrine neoplasm (NEN) features? types?

• intramural masses, salt + pepper chromatin, chromogranin(+), synaptophysin(+)

• type 1= atrophic gastritis → inc. gastrin + dec. HCl

• type 2= gastrinoma MEN1 → dec. gastrin + inc. HCl

• type 3= sporadic → normal gastrin + HCl