Download Anatomy Blue Boxes Exam 1 Esophagus and Stomach Pgs 254

Anatomy Blue Boxes Exam 1
Esophagus and Stomach
Pgs 254-257
Esophageal Varices: in portal HTN blood is unable to pass to pass to the liver and causes submucosal veins to enlarge
esophageal varices (may rupture and be unable to contain surgically)
Pyrosis: “heartburn” burning sensation result of regurgitation of food or gastric fluid into lower esophagus
May be associated with hiatal hernia
Displacement of Stomach: pancreatic pseudocysts and abscesses in omental bursa can push stomach anteriorly
Hiatal Hernia: protrusion of part of stomach into mediastinum through the esophageal hiatus of diaphragm
Occur after middle age due to muscular weakening
Paraesophageal hiatal hernia: cardia remains in its normal position but pouch of peritoneum extends through
the esophageal hiatus
Usually no regurgitation of contents due to cardia being in place
Sliding hiatal hernia: abdominal part of esophagus, cardia and parts of fundus slide superiorly
Some regurgitation is possible
Pylorospasm: spasmodic contraction of pylorus in 2-12 weeks
Failure of smooth mm fibers encircling pyloric canal to relax (food doesn’t pass from stomach to duodenum)
Congenital Hypertrophic Pyloric Stenosis: thickening of smooth mm in pylorus
More common in males than females and peristalsis pushes chime to SI at irregular intervals
Stomach may be dilated proximally
Carcinoma of Stomach: seen using gastroscope, hard to remove associated lymph nodes
Gastrectomy and Lymph Node Resection: total gastrectomy (total stomach removal) is rare
Partial gastrecomy may be used for carcinoma
Anastamoses allow arteries to be ligated easily without losing blood supply
Removal of pyloric ad gastro-omental lymph nodes is easily done and important to stop spread
Gastric Ulcers, Peptic Ulcers, Helicobacter pylori, and Vagotomy
Gastric ulcers: open lesions of mucosa of stomach
Peptic ulcers: lesions of mucosa of pyloric canal or duodenum
Most ulcers are associated with Helicobacter pylori higher acid secretion and H. pylori
Vagotomy: surgical section of vagus nerve in people that have chronic ulcers
Truncal vagotomy: rarely performed due to compromise of other structures
Selective gastric vagotomy: stomach is denervated (pancreas, liver, bile duct, intestines preserved)
Selective Proximal vagotomy: denervate the area where parietal cells are located
Posterior gastric ulcer: may erode through stomach wall into pancreas (referred pain in back)
Erosion of splenic artery severe hemorrhage into peritoneal cavity
Visceral Referred Pain: organic pain comes from organ such as stomach
Visceral referred pain: referred to epigastric region because the stomach is supplied by pain afferents that reach
T7-8 (brain interprets pain through irritation of skin)
Pain arising from parietal peritoneum is of somatic type and usually severe
Digital pressure relieves pain and when removed sharp pain occurs
Small and Large Intestine
Pgs 257-261
Duodenal Ulcers: inflammatory erosions of duodenal mucosa (65% are posterior wall)
Can perforate the duodenal wall and cause peritonitis
Eroion of gastroduodenal artery by a duodenal ulcer results in severe hemorrhage into peritoneal cavity
Developmental changes in Mesoduodenum: during early fetal period the entire duodenum has a mesentery )fuses with
posterior abdominal wall because of pressure from overlying transverse colon
Duodenum and pancreas can be separated from underlying retroperitoneal viscera during surgical operations
involving duodenum without endangering the blood supply to kidney or ureter
Paraduodenal Hernias: paraduodenal fold and fossa are large and to the left of the ascending duodenum
A loop of the intestine enters this fossa and may become strangulated (watch inf. Mesenteric artery)
Anatomy Blue Boxes Exam 1
Brief Overview of Embryological Rotation of Midgut: foregut= esophagus, stomach, pancreas, duo, liver, bile ducts
Midgut= Small Intestine, cecum, appendix, ascending colon, most of transverse colon (periumbilical region)
Hindgut= distal transverse colon, descending colon, sigmoid colon, rectum (hypogastric region)
4 weeks: midgut is herniated into umbilical cord attached to yolk sac rotates 270 around axis of SMA and then
returns to cavity mesenteries shorten and malrotation can lead to volvulus
Navigating Small Intestine: when portions of the SI have been delivered through surgical wound follow the intestine in a
particular direction and figure out the ends
Ischemia of Intestine: Occlusion of the vasa recta by emboli results in ischemia of part
Necrosis of involved segment results and ileus (obstruction of intestine) occurs (severe colicky pain with
abdominal distention, vomiting, fever and dehydration
Ileal Diverticulum (Meckel): proximal part of yolk sac remains may be free or attached to umbilicus
Ileal diverticulum may become inflamed and produce pain mimicking appendicitis
Position of appendix: anatomical position determines the symptoms and site of mm spasm and tenderness
Retrocecal: extends superiorly toward right colic flexure
Base lies in an oblique line joining right ASIS to umbilicus (McBurney point or spino-umbilical line)
Appendicitis: digital pressure over McBurney point
In younger people: caused by hyperplasia of lymphatic follicles in appendix that occlude lumen
In older people: obstruction usually from fecalith (fecal matter)
When secretions from appendix cannot escape, appendix swells and stretches visceral peritoneum
Pain of appendicitis is periumbilical, later RLQ pain from posterior wall and extending thigh elicits pain
Acute infection thrombosis of appendicular artery ischemia, gangrene,
Rupture can cause infection of peritoneum, pain, nausea and vomiting, abdominal rigidity
Appendectomy: Surgical removal may beperformed through transverse of gridiron incision
Laparoscopic: standard procedure with peritoneal cavity extended with CO2 to view space and portals
Mobile Ascending Colon: inferior part of ascending colon has mesentery and may cause volvulus of colon
Colitis, Colectomy, Ileostomy, Colostomy: colitis is chronic inflammation of colon (severe inflammation and ulceration)
Colectomy: terminal ileum and colon are removed
Ileostomy: constructs a stroma and colostomy is cutaneous opening for feces
Colonoscopy: long, flexible fiberoptic endoscope inserted through anus and rectum
Most tumors appear at retrosigmoid junction
Diverticulosis: multiple false diverticula (outpouchings) in middle aged and elderly people
Subject to infection and rupture and lead to diverticulitis
Can distort and erode the nutrient arteries leading to hemorrhage
Dietary fiber reduces the occurrence
Volvulus of Sigmoid Colon: results in obstruction of the lumen of descending colon and constipation and ischemia
fecal impaction and necrosis
Embryology—Ch 11 Alimentary System Blue Boxes
Pgs 212-242
Esophageal Atresia: 1/3 of affected infants are born prematurely
Results from deviation of tracheoesophageal septum in posterior direction
Associated with tracheoesophageal fistula in >90% of cases
Fetus with EA is unable to swallow amniotic fluid and nutrients from amniotic fluid cannot be absorbed through
intestine and transported to maternal blood for disposal
polyhydraminos (accumulation of excessive amniotic fluid)
Excessive drooling can be seen after birth with rejection of oral feeding
Esophageal stenosis: Narrowing of the lumen of the esophagus usually occurs in distal 1/3 as web or thread-like lumen
Results from imcomplete recanalization of the esophagus during the 8th week or from failure of bv’s to form
Duodenal Stenosis: usually results from incomplete recanalization of duodenum from defective vacuolization
Stomachs contents are often vomited
Anatomy Blue Boxes Exam 1
Duodenal Atresia: not common, from incomplete recanalization
Occurs usually at junction of bile and pancreatic duts (hepatopancreatic ampulla)
Vomit begins within hours of birth from overfilled stomach and bile vomiting is common
Associated with: annular pancreas, CV defects, anorectal anomalies, malrotation
1/3 of infants affected have Down syndrome; 20% are premature
Polyhydraminos occurs and a presence of a “double-bubble” is seen due to distended, gas filled stomach and
proximal duodenum
Anomalies of Liver: can have accessory hepatic ducts (in 5% population and not troublesome)
Accessory ducts run from right lobe of liver to anterior gallbladder
Extrahepatic Biliary Atresia: most common form is obliteration of bile ducts
Could result from failure of remodeling process at hepatic hilum from infections or immunologic reactions
during late fetal development
Jaundice occurs after birth and stools are clay colored
Ectopic Pancreas: most often located in wall of stomach, duodenum, jejunum (presents with obstruction, bleed, cancer)
Annular Pancreas: rare but can cause duodenal atresia
Infants present with complete or partial bowel obstruction
May be associated with Down Syndrome, malrotation, cardiac defects (females>males)
Due to growth of bifid ventral pancreatic bud around duodenum
Accessory Spleens (Polysplenia): one or more small splenic masses commonly near hilum of spleen in tail of pancreas or
within gastrosplenic ligament
Occurs in 10% of people
Congenital Omphalocele: persistence of herniation of abdominal contents into umbilical cord
Abdominal cavity is small due to nothing growing inside of it
Surgical repair is required
Results from impaired growth of mesodermal (muscle) and ectodermal (skin) components of abdominal wall
Covering of the hernia sac is epithelium of umbilical cord
Umbilical Hernia: intestines return to abdominal cavity (10th week) and herniated through imperfectly closed umbilicus
Protruding mass is covered by mm and skin
Usually occurs through linea alba when crying, straining, cough
Can be reduced through fibrous ring at umbilicus (surgery not performed til 3-5 years)
Gastroschisis: defect lateral to median plane of anterior abdominal wall (usually right)
Extrusion of abdominal viscera without involving umbilical cord
Caused by: ischemic injury, rupture of wall, weak wall, rupture of omphalocele
Anomalies of the Midgut: malrotation (when reenters the abdomen) SI on right, LI on left
Peritoneal bands and volvulus of intestine causes duodenal obstruction (failure of final 90 degrees)
Midgut volvulus sup mesenteric artery obstruction, infarction and gangrene with bilious emesis
Reversed Rotation: midgut rotates clockwise duodenum lies anterior to sup mesenteric artery and transverse colon
may be obstructed by pressure
Subhepatic Cecum and Appendix: if cecum adheres to inferior surface of liver when it returns to the abdomen it will be
drawn superiorly as liver diminishes
May be a problem when diagnosing appendiditis
Mobile Cecum: 10% of people have abnormal amount of motion (may herniated into right inguinal canal
Internal Hernia: SI passes into mesentery of midgut loop in return of intestines into abdomen
Stenosis and Atresia of Intestine: ileum (50%) and duodenum (25%) mainly
Can be from faulty recanalization, interruption of blood supply (fetal vascular accident
Ileal Diverticulum and Omphaloenteric Remnants: outpouching of ileum is common
Ileal Diverticulum may be connected to umbilicus by fibrous cord or omphaloenteric fistula
Duplication of Intestine: most are cystic or tubular (cystic more common)
Tubular communicate lumens
Usually due to failure of normal recanalization
Anatomy Blue Boxes Exam 1
Congenital Megacolon or Hirschsprung Disease: inherited multigenic disorder with incomplete penetrance
RET proto-oncogene is major susceptibility
Absence of ganglion cells (aganglionosis) in bowel—absence of Neural crest cell migration through wall in 5th-7th
weeks (no parasympathetic ganglion cells in Auerbach and Meissner plexuses)
Dilation results from failure of relaxation of aganglionic segment
Usually only in rectum and sigmoid colon
Accounts for 33% of neonatal obstructions
Anorectal Anomalies: most from abnormal development of urorectal septum (incomplete separation of cloaca into
urogenital and anorectal parts)
Imperforate anus: anal canal ends blindly or ectopic anus
Anal stenosis: canal narrow
Membranous atresia: anus in normal position but thin layer of tissue between anus and exterior
Anorectal agenesis with fistula: incomplete separation (may be vestibule into vagina or penis)
Rectal atresia: anal canal and rectum are present but separated