GI Physiology Flashcards
What are the VACTERL defects associated with omphalocele?
Vertebral defects, Anal atresia, Cardiac Defects, TEF, Renal defects, Limb defects
associated with aneuploidy
Omphalocele and Gastrochisis result from defect of which ventral wall closer?
Lateral wall
Rostral fold closure results in which ventral wall defect?
Sternal defect
Caudal fold closure defect results in which ventral wall defect
Bladder exstrosphy
Polyhdramnios, drool, choking, vomiting with first feeding and air in stomach suggest which anomaly?
Tracheoesophageal fistula (esophageal atresia)
Cause of duodenal atresia
Failure to recanalize
“double bubble” on X-ray with bilous vomiting and abdominal distension in first 1-2 days of life suggest
duodenal atresia
“triple bubble sign” with bilious vomiting and abdominal distension in first two days of life suggest
jejunal and ileal atresia
cause of jejunal and ileal atresia
disruption of superior mesenteric vessels–> ischemic necrosis–> segmental resorption
Common cause of jejunal and ileal atresia
Malrotation leading to occlusion of SMA and ischemic necrosis
A “palpable olive mass” in epigastric region and nonbilous projectile vomiting at 2-6 weeks old is suggestive of
Hypertrophic Pyloric stenosis
Maternal use of macrolides during pregnancy is associated with
Hypertrophic pyloric stenosis
Hypokalemic, hypochloremic metabolic alkalosis in a hungry, dehydrated baby suggest
Hypertrophic pyloric stenosis
The uncinate process and main pancreatic duct are derived from
Ventral pancreatic buds
The body, tail, isthmus and accessory pancreatic duct are derived from
Dorsal pancreatic bud
What is special about the spleen’s embryologic arrangement
Derived from mesentery of stomach (mesoderm) but has foregut supply (splenic artery)
Retroperitoneal structures (SADPUCKER)
Suprarenal (adrenal) glands Aorta and IVC Duodenum (2 and 4) Pancreas (except tail) Ureters Colon (ascending and descending) Kidneys Esophagus (thoracic) Rectum (partially)
Foregut structures supplied by celiac artery
lower esophagus to proximal duodenum, liver, gallbladder, pancreas, spleen
Midgut structures supplied by SMA
Distal duodenum to proximal 2/3 of transverse colon
Hindgut structures supplied by IMA
Distal 1/3 of transverse colon to upper portion of rectum
What is SMA syndrome (Wilkie’s syndrome)
Occasional post-prandial pain due to compression of third portion of duodenum between SMA and aorta; occurs in malnutrition/low body weight
Which arteries provide anastamoses between IMA and SMA?
Middle colic (SMA) and Left colic (IMA)
The right gastric artery branches off of which vessel?
Proper hepatic arterty
Three GI arteries that branch off of celiac
Common hepatic, L. gastric, Splenic
The short gastrics and L. gastroepiploic arteries branch off of
Splenic artery
Lower esophagus blood is provided by
Left gastric artery
Superior hemorrhoids occur in which vein
Superior rectal
Anorectal varices in cirrhosis occur due to anastomosies between
Superior rectal and middle and inferior rectal vein s
Caput medusae around umbilicus occurs due to anastamoses between which two veins?
Paraumbilical to small epigasteric veins of small anterior abdominal wall
Esophageal varices occur due to abnormal anastamoses between
Left gastric and azygos
What is TIPS
Transjugular intrahepatic portosystemic shunt to treat portal hypertension
How is TIPS performed
Shunt placed between portal vein and hepatic vein to bypass liver and shunt blood to systemic circulation
Which structure is formed where endoderm meets ectoderm
Pectinate (dentate) line
Why are internal hemorrhoids not painful
Receive visceral innervation
Lymph drainage of structures above pectinate line
Internal iliac lymph nodes
Arterial supply of structures above pectinate line
Superior rectal artery
Arterial supply of structures below pectinate line
Inferior rectal artery (branch of internal pudendal)
Venous drainage of structures below pectinate line
Inferior rectal vein–> internal pudendal vein–> internal iliac vein–> common iliac vein–> IVC
Venous drainage of structures above pectinate lin e
Superior rectal vein –> inferior mesenteric vein–> portal vein
Lymphatic drainage of structures below pectinate line
Superficial inguinal lymph nodes
Inferior rectal branch of pudendal nerve innervates which part of body
Structures below pectinate line (external hemorrhoids–painful)
Which hepatic zone contains P450, is most sensitive to metabolic toxins, is first affected by ischemia, and is the first site of alcoholic hepatitis?
Zone 3 (pericentral vein/centrilobular zone)
Which hepatic zone is affected by yellow fever?
Zone 2 (Intermediate zone)
Which hepatic zone is affected first by viral hepatitis and bacterial/infectious toxins?
Zone 1 (Periportal zone)
Which cells store Vitamin A when quiescent and produce ECM when active?
Hepatic stellate (Ito) cells in space of Disse
Which cells are the macrophages of the liver?
Kupffer cells lining sinusoids
What is the site of protrusion of indirect hernia
Deep (internal) inguinal ring
What is the site of protrusion of direct hernia?
Abdominal wall
The internal spermatic fascia forms from the
Transversalis fascia
The cremasteric muscle and fascia form from
Internal oblique
The external spermatic fascia form from
External oblique
ICE tie
Internal spermatic fascia - transversalis fascia
Cremasteric muscle and fascia- internal oblique
External spermatic fascia- external oblique
What is the site of femoral hernias
Femoral ring
What is the most common cause of indirect inguinal hernias in males
Patent processus vaginalus (risk of hydrocele)
Which anatomic structures help distinguish Indirect hernias from direct hernias?
Inferior Epigasteric vessels
Location of direct hernia relative to inferior epigastric vessel
Medial to inferior epigastric vessel
Location of indirect hernia relative inferior epigastric vessel
Lateral to inferior epigastric vessels
Internal ingunal ring, external inguinal ring, into scrotum (which hernia)
Indirect inguinal
Two complications of hernias
Incarceration (not reducible back into abdomen/pelvis) and strangulation (ischemia and necrosis)
Cutting which ligament provides access to pancreas in lesser sac during surgery?
Gastrocolic
Which structure does direct inguinal hernia go through
External inguinal ring
What is direct inguinal hernia covered with and who usually gets it
External spermatic fascia; older men
What are the borders of Hesselbach’s triangle
Superior: Inferior epigasteric vessels
Medial: Lateral border of rectus abdominus
Inferior: Inguinal ligament
Where does femoral hernia protrude through and who usually gets it
Below inguinal ligament through femoral canal; females
What is the risk assocaited with femoral hernias
Incarceration and strangulation
Cause of umbilical hernias
Weakened rectus abdominus muscle; protrusion of allantois remnant
Why do diaphragmatic hernias typically occur on left side?
The right hemidiaphgragm is protected by the liver
What is the most common diaphragmatic hernia?
Sliding hiatal hernia (gasteroesophageal junction displaced upward) “Hourglass stomach”
Sliding hiatal hernias are associated with which condition
GERD
Presentation of diaphragmatic hernia on newborn
Tachypnea, dyspnea, cyanosis, absent bowel sounds, scaphoid abdomen, hypoplastic left lung
dx with US
Risk of paraesophageal diaphragmatic hernia
gastric volvulus (stomach fundus flips onto itself, GE junction is usually normal)
Which three conditions increase gastrin production?
Chronic PPI use, Zollinger-Ellison syndrome (gastrinoma), H Pylori
Which medications increase motilin and thus migrating motor complexes
Erythromyciin
Clinical presentation of VIPoma
Watery diarrhea, Hypokalemia and Achlorydia (WDHA syndrome)
What causes increased lower esophageal sphincter tone in achalasia
Loss of NO
What converts trypsinogen to trypsin and where is it found
Enterokinase/enteropeptidase, brush border of duodenal and jejunal mucosa
Where is Iron (Fe+2) absorbed
Duodenum
Where is Folate absorbed
Jejunum
Where is B12 absorbed
Terminal ileum along with bile salts; requires intrinsic factor
Where do you find Peyer’s patches
Lamina propria and submucosa of ileum
Predominant antibody of Peyer’s patches
IgA
Which enzyme catalyzes rate-limiting step of bile acid synthesis
Cholesterol-7 alpha-hydroxylase
Three major functions of bile
- Digestion and absorption of lipids and fat-soluble vitamins
- Cholesterol excretion
- Antimicrobial activity
6 components of Bile
Bile salts (bile acids + Glycine/Taurine) Ions Water Cholesterole Biliirubin Phospholipids
What is bilirubin conjugated with
Glucuronate by UGT1
How is unconjugated bilirubin transported in blood
Attached to albumin
Failure of facial prominences to fuse causes
Cleft lip and palate
What is Behcet syndrome
Recurrent apthuous uclers, genital ulcers and uveitis due to immune complex vasculitis involving small vessels
What are the major risk factors for squamous cell carcinoma of oral cavity
Tobacco and alcohol
Leukoplakia and erythroplakia must be biopsied to rule out
Squamous cell carcinoma
What causes Hairy leukoplakia
EBV induced squamous cell hyperplasia in immunocompromised individuals; occurs on lateral tongue
Mobile, painless, circumscribed mass at angle of jaw is suggestive of which condition and containes which tissues
Pleomorphic adenoma; stromal and epithelial tissue
Most common salivary gland tumor
Pleomorphic adenoma
Common site of Warthin tumor
Parotid gland
Histology of Warthin tumor
Abundant lymphocytes and germinal centers (lymph-node like stroma); benign tumor
Most common cause of sialadenitis
S. aureus infection following obstructing stone
Most common malignant tumor of parotid gland
Mucoepidermoid carcinoma (mucinous and squamous cells)
Why does mucoepidermoid carcinoma cause pain
Involves facial nerve
Clinical presentation of Plummer-Vinson syndrome
1) Dysphagia
2) Esophageal web
3) Iron deficiency anemia
Increased risk of squamous cell carcinoma
Zenker diverticulum occurs where?
In opening of cricopharnyngeal muscle
Three clinical features of Zenker diverticulum
Halitosis, dysphagia, feeling of obstruction, especially nocturnal
Longitudinal lacerations at gastroesophageal junction due to excessive vomiting (alcoholics and bulemics) suggest which condition
Mallory-Weiss syndrome
How does Mallory-Weiss syndrome present
Painful hematemesis (bloody vomit); risk of Boaerhaave syndrome
Clinical sign of Boerhaave syndrome
Crepitus in neck after severe vomiting, suggesting esophageal rupture
What causes achalasia
Damaged ganglion cells in myenteric plexus (no NO so LES cannot relax)
Trypanasoma cruzi infection in Chagas disease increases risk of which condition
Achalasia
Four signs of Achalasia
Dysphagia for solids and liquids
Putrid breath
High LES pressure on manometry
Bird beak sign on barium swallow study
What is Nutcracker esophagus
Overactivity of cholinergic neurons causing persistaltic contraction of high amplitude, dysphage for solids and liquids or asymptomatic
Heartbburn, adult-onset asthma and cough, damage to enamel of teeth and ulceration are indicative of which condition?
GERD
Risk factors for GERD
Alcohol, tobacco obesity, fat-rich diet, caffeine and hiatal hernia
What causes GERD
Reduced LES tone
What is Barrett esophagus
Metaplasia of lower esophageal mucosa from stratified squamous epithelium to nonciliated columnar epithelium with goblet cells. May progress to dysplasia and adenocarcinoma
Where is esophageal adenocarcinoma most common
the West
Which is the most common esophageal cancer worldwide?
Squamous cell carcinoma (upper or middle third of esophagus)
Squamous cell carcinoma typically spreads through which lymphatics
Upper 1/3 - cervical nodes
middle 1/3- mediastinal or tracheobronchial nodes
Adenocarcinoma spreads through which lymph routee
Lower 1/3- celiac and gastric nodes
Most common cause of esophageal squamous cell carcinoma
Alcohol and tobacco
Hot tea in East
Labs for baby with pyloric stenosis
Hypochloremia, hypokalemic metabolic alkalosis, increased bilirubin
HSV-1 esophagitis presents as
punched-out ulcers
CMV esophagitis presents as
linear ulcers
Candida esophagitis presents as
white pseudomembranes
What are esophageal strictures associated with
caustic ingestion and GERD
How does CREST syndrome cause acid reflux and dysphagia
Causes esophageal smooth muscle atrophy, leading to decreased LES tone and reflux
Risk factors for esophageal adenocarcinoma
GERD, Barrett esophagus, obesity, smoking, achalasia
Two types of esophageal cancers
Adenocarcinoma
Squamous Cell carcinoma
both poor prognosis
Meconium ileus is a very specific finding for which condition?
CF
Clinical feature of meconium ileus
Green inspissated mass (dehydrated meconium) in distal ileum
Most common cause of death of patients with meconium ileus (CF)
Pneumonia, bronchiectasis and cor pulmonale
Progressive dysphagia (solids to liquids), weight loss, pain and hematemesis suggest
Esophageal carcinoma
Which gastric carcinoma also presents with hoarseness and cough
Squamous cell carcinoma due to involvement of recurrent laryngeal nerve or trachea
What causes a curling ulcer
Severe burns
What causes a Cushing ulcer
Increased intracranial pressure (stimulates vagus nerve to increase acid production)
6 risk factors for acute gastritis
Curling ulcer, NSAIDs (decrease PG32), heavy alcohol consumption, chemo, Cushing ulcer, hypotensive shock (decreased nutrient delivery to mucous/foveolar cells)
Clinical presentation of duodenal ulcer
Epigastric pain that improves with meals
Most common cause of duodenal ulcers (95%)
H. Pylori
Rare cause of duodenal ulcer
ZE syndrome
What risks are associated with a ruptured ulcer in posterior duodenum?
Bleeding from gastroduodenal artery or acute pancreatitis
Diagnostic endoscopy of duodenal ulcer
Ulcer with hypertrophy of Brunner glands
Risk factors for intestinal type gastric carcinoma
- Intestinal metaplasia (autoimmune/ H. pylori)
- Smoked foods (Japan)
- Blood type A
Diffuse type gastric carcinoma profile
Young, worse prognosis, occurs in entire stomach, signet ring cell s
What is the Leser-Trelat sign and what does it indicate
Sudden occurrence of keratoses all over skin; gastric malignancy
Intestinal gastric carcinoma lymph drainage
Periumbilical region (Sister Mary Joseph nodule)
Gastric carcinoma drains to lymph nodes via
Left supraclavicular node (Virchow node
Diffuse type gastric carcinoma drains to which organ
bilateral ovaries (Krukenberg tumor)
Cause of duodenal atresia
Failure of duodenum to canalize
A 1-2 year old with bleeding, volvulus, intussusception or appendicitis-like symptoms may present with
Meckel diverticulum (true diverticulum)
Cause of Meckel diverticulum
Failure of vitelline duct to involute
Most common location of volvulus in elderly
Sigmoid colon
Most common cause of volvulus in young adults
cecum
Most common cause of intussusception (telescoping bowel) in children
Rotavirus infection
Occlusion of which two vessels can cause small bowel infarction?
SMA or mesenteric vein
Clinical features of small bowel infarction
Abdominal pain, bloody diarrhea, decrease bowel sounds, hypotension
Which antigen do APCs present on MHCII in Celiac disease?
deamidated gliadin
What causes dermatitis herpetiformis in patients with Celiac disease?
Deposition of IgA on dermal papillae
Flattening of villi, hyperplasia of crypts and increased intraepithelial lymphocytes indicate which condition
Celiac disease
Where is damage in Celiac disease
Duodenum
What is tropical sprue
Malabsorption disorder common in tropics; damage most prominent in jejunum and ileum
Triad of symptoms with Whipple disease (CAN) along with steatorrhea
Cardiac symptoms (murmur) Arthralgias (arthritis) Neurologic symptoms (confusion, forgetfulness)
Why does Whipple disease cause steatorrhea
Infiltration of small bowel lacteals prevents chylomicron absorption
Causative agent of Whipple disease and histology
Tropheryma whippeli; foamy macrophages in lamina propria (connective tissue of SI villus)
Clinical features of abetalipoprotenemia
AR, deficiency of APO B-48 (chylomicrons) and B-100 (VLDL, LDL)
Malabsorption of fat (Steatorrhea)
absent plasma VLDL and LDL
Clinical features of carcinoid syndrome
Flushing, bronchospasm and diarrhea
Why does carcinoid heart disease only lead to right-side valvular fibrosis (tricuspid regurg and pulmonary stenosis)?
The lungs have MAO, which break down serotonin before it reaches left side of heart
Three major clinical features of Hirschsprung disease
- Failure to pass meconium
- Empty rectal vault on digital rectal exam
- Massive dilatation of bowel proximal to obstruction
Cause of Hirschsprung disease
Failure of neural crest cells to migrate into Auerbach (meynteric) and Meissner (submucosal) plexuses
Which part of colon is defective in Hirschsprung
distal sigmoid colon and rectum (associated with Trisomy 21)
Most common location for colonic diverticula
Sigmoid colon
What is diverticulitis
Inflammation of diverticuli (mucosal/submucosal outpouchings into muscularis propria) that cause LLQ pain and hematochezia (bloody stool); common in elderly, especially those with low-fiber diets
Presentation of AD Hereditary Hemorrhage Telengiectasia
Ecchymoses of lips, GI bleeds
High stress in right colon causes; high stress in left colon causes
Angiodysplasia right; Diverticulosis left
Three clinical features of ischemic colitis
Post-prandial LUQ pain
Bloody diarrhea
Weight loss
Common area of ischemic colitis
Splenic flexure (watershed area between SMA and IMA)
Most common cause of Ischemic Colitis
Atherosclerosis of SMA
Bloating, flatulence and change in bowel habits (diarrhea or constipation) without any identifiable cause is termed
Irritable bowel syndrome
How is aspirin protective in the adenoma-carcinoma sequence?
Prevents progression from adenoma to carcinoma by inhibiting expression of COX
What are the three risk factors for progressing to carcinoma?
1) size >2cm
2) sessile growth
3) villous histology
Two types of FAP syndromes
Garner and Turcot
What is Gardner syndrome
Familial Adenomatous Polyposis syndrome with colonic cancer (thousands of polyps in colon and rectum) and osteomas and soft tissue tumors
What is Turcot syndrome
FAP with colorectal carcinoma and CNS tumors (medulloblastoma/glioblastoma)
How is FAP inherited
AD mutation of APC on chromosome 5 (Endoscopy warranted in people with family history of colorectal cancer)
Rectal polyps in children <5 yo are likely
Hamartomatous (disorganized tissue) juvenile polyps
Clinical presentation of intussusception (target bowel on CT), hamartomatous polyps in small bowel, bluish spots/hyperpigmented freckle-like spots on lips, oral mucosa, palms and genitals in a young adult suggest
Peutz-Jeghers syndrome
Peutz-Jehger syndrome is mutation in which gene and increases risk of which malignancies
AD STK1 (serine threonine kinase) mutation, breast, colorectal, gynecologic cancer
Colorectal cancer on right side with other cancers such as ovarian and endometrial suggest
Lynch (HNPCC) syndrome
Decreased stool caliber, LLQ pain and blood-streaked stool suggestive of left-sided colorectal cancer arose from which mutation
Adenoma-Carcinoma sequence (APC, KRAS, TP53 mutations)
Raised lesions, Iron-deficiency anemia and vague pain in an older adult suggestive of right-sided colorectal carcinoma likely arose from
MSI (alternate) sequence; microsatellite instability
Streptococcus bovis endocarditis is highly suggestive of
colonic carcinoma
Which organ is most commonly involved in GI cancers?
Liver
Which serum marker is useful for assessing treatment response and detecting recurrence of colonic cancer?
CEA
What is the source of visceral pain and why is it poorly localized? (described as vague, colicky, aching, crampy)
Source is mesentary– due to low density of pain receptors with shared sensory convergence
Visceral pain is indicative of which sort of stimulus
Tension, overdistension, ischemia, mesenteric traction
What is the source of parietal pain and why can it be precisely located (sharp, knife-like, constant, severe)
Peritoneal lining of abdominal wall; somatic free nerve ending meshwork with increased sensory nerves allows fine mapping
Stimuli for parietal pain
Mechanical, chemical, thermal irritation
Cause of annular pancrease
Failed migration of ventral pancreatic bud around duodenum
How does alcohol increase risk of acute pancreatitis
Causes premature contraction of sphincter of Oddi, decreases drainage of pancreas, increases risk of premature activation of enzymes
Trauma, hypercalcemia, hyperlipidemia, drugs, scorpion stings, rupture of posterior duodenal rupture and mumps can cause
acute pancreatitis
Which serum enzyme is specific for pancreatic damage?
Lipase
Abdominal mass with persistently elevated serum amylase suggests
Pancreatic pseudocyst
Abdominal pain, fever, and persistently elevated amylase suggests pancreatic abscess formation by which pathogen
S. aureus
Mutated PRSS1, SPINK1 (trypsin inhibitor) and CF increase risk of
pancreatitis
Most common cause of chronic pancreatitis in children
CF
Obstructive jaundice, pale stools, palpable gallbladder suggest
Pancreatic adenocarcinoma
Most common cause of pancreatic adenocarcinoma
smoking and chronic pancreatitis
Neonatal presenation of jaundice and progression to cirrhosis in first 2 months of life suggests
Biliary atresia (failure/early destruction of extrahepatic biliary tree)
Which condition presents as air in biliary tree?
gallstone ileus
Three risk factors for hepatocellular carcinoma
Chronic hepatitis
Cirrhosis
Aflatoxins from Aspergillus
Hepatic vein obstruction that results in painful hepatomegaly and ascites is likely
Budd-Chiari syndrome
Serum tumor marker for hepatocellular carcinoma
alpha-fetoprotein
What causes asterixis in cirrhosis?
Buildup of ammonia
Treatment for hepatic encephalopathy and asterixis in cirrhosis
Lactulose (increase H+ bacteria –> increase NH4+ for excretion)
Neomycin (kill NH3 producing bacteria)
Which second messenger increases with Histamine binding to H2 receptors on parietal cells
cAMP
Which second messenger is increased with ACh binding M3 muscarinic receptors on parietal cells
Intracellular calcium
Which second messenger is increased with Gastrin binding to CCK B receptors
Intracellular calcium
Patient comes with syncope, flushing, hypotension, pruritus and urticaria after showering. Skin biopsy reveals mast cells positive for KIT (CD117). Patient likely has which condition?
Systemic mastocytosis
What causes systemic mastocytosis
Mutation in KIT receptor tyrosine kinase, leads to excessive histamine release
A rigid and tender abdomen with persistent left shoulder pain and bruise on lower chest wall after MCV indicates
Splenic laceration
Why do some people get C Diff infections when exposed while others may not?
Protection from GI microbiome
What are the markers of liver hepatocyte injury
Elevated AST and ALT (AST usually > ALT in cirrhosis)
What are the markers of cholestasis/biliary injury
Elevated alkaline phosphatase, elevated GGT
What are the markers of impaired liver biosynthetic activity that help evaluate liver function
Elevated prothrombin time, hypoalbuminemia and elevated bilirubin
What is the key determinant of prognosis in patients with cirrhosis?
Liver’s functional reserve (prothrombin time, albumin levels)
Diffuse hepatic fibrosis with replacement of normal lobular architecture by fibrous-lined regenerative parenchymal nodules indicates
Cirrhosis
Granulomatous destruction of bile ducts is seen in which condition
Primary biliary cirrhosis
What is the most common GI manifestation of cystic fibrosis
Pancreatic insufficiency characterized by duct obstruction and distension
Where in the retroperitoneum is the esophagus located
Behind the trachea (appears black on CT) and in front of spine
Light microscopy showing apoptosis of hepatocytes, acinar necrosis and periportal mononuclear inflammatory infiltration indicates
Viral hepatitis
Light microscopy of liver showing microvesicular steatosis, presence of small fat vacuoles in cytoplasm of hepatocytes indicates
Reye syndrome
Centrilobular congestion occurs in patients with which condition
RHF
Middle-aged woman complaining of severe pruritus, PMH of autoimmune disease, xanthometous lesions on eyelids or tendons, and elevated AST>ALT indicates
Primary biliary cirrhosis
Which organs are the two primary sources of alkaline phosphatase
Bone and liver
Why check GGT after noticing elevated alkaline phosphatase?
GGT is mainly expressed in GB and liver and can distinguish whether origin of AP elevation is related to bone dz or hepatobiliary dz
Hepatitis B assists Hepatitis D infect an organism through which mechanism
Coating Hepatitis D viral particles to penetrate hepatocyte
Common life-threatening complication of noncompliant ulcerative colitis patient
Toxic megacolon (bloody diarrhea, abdominal pain/distension, fever, shock)
Most benign liver tumor that looks like enlarged ectasia with blood cells in the gaps
Cavernous hemangioma
What is the most sensitive screening for malabsorptive disorders
Testing for fat in stool using Sudan III stain
As a consequence of total gastrectomy, patients require lifelong supplementation of
B12
What causes gynecomastia, testicular atrophy, decreased body hair and spider angiomata in cirrhosis?
Decreased estrogen metabolism by liver, increased androstenedione production leading to increased conversion to estrogen by adrenal glands, thus decreasing free testosterone/estrogen ratio
Where do most gastric ulcers arise and which arteries are at risk of hemorrhage?
Lesser curvature of stomach. Left gastric at proximal, right gastric at distal
Ulcers in the posterior duodenal bulb can erode and cause hemorrhage in which artery?
Gastroduodenal
The greater curvature of the stomach is supplied by which arteries?
Left (Branch of splenic) and right gastroepiploic (branch of gastroduodenal/common hepatic)
Most common site of intussusception in children less than 2
Ileocecal valve
Nodules of cirrhotic liver are composed of
Hepatocytes
These cells of the liver lack a basement membrane
Sinusoidal endothelial cells
This liver cell differentiates into myofibroblasts in injury and causes fibrosis
Stellate cell
Entaemoeba histolytica infections (abdominal pain and diarrhea) are more common in which demographic?
Men who have sex with men
Stool examination of Entamoeba histolytica reveal
Trophozoites with phagocytosed RBCs
Stool samples of Cryptosporidium parvum reveal
Large number of oocysts, especially in AIDS pts
Sudden, fouls-smelling watery diarrhea with cramping after a camping trip; and stool exam with cysts or trophozoites suggests
Giardia lamblia infection
Described as friable, inflamed mucosa beginning from rectum and ascending proximally. Also have neutrophils in crypts
Ulcerative Colitis