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Flashcards in GI embryology and anatomy Deck (22):

What does the foregut include? Midgut? Hindgut? Describe midgut development? What are some pathologies that can occur during that development?

foregut=pharynx to duodenum

Midgut: duodenum to proximal 2/3 of transverse colon

Hindgut: distal 1/3 of transverse colon to anal canal above pectinate line

6th week: herniates into umbilical ring
10th week: reenters abdominal cavity and rotates around SMA

malrotation of midgut, omphalocele, intestinal atresia or stenosis, volvulus


What is gastrochisis? Omphalocele? What causes duodenal atresia? Jujunal, ileal, and colonic atresia?

Extrustion of abdominal contents through abdominal folds-not covered by peritoneum

persistenc of henrniation of abdom. contents into umbilical cord-covered by peritoneum (sealed)


What is the most common tracheoesophageal anomaly. Decribe it. What are the symptoms? Waht is found on CXR? Diagnosis? What is the H type like? Pure EA?

EA with distal TEF is most common

Blind pouch in esophagus with a distal connection from trachea to distal esophagus

Drooling, choking, and vomiting with first feeding
cyanosis due to laryngospasm

Air in stomach on CXR

Faillure to pass NG into stomach

Htype: No blind pouch but a distal TEF



What is the pathophys of cong. pyloric stenosis? What is the presentation? Gender? What are the results? Treatment?

Hypertrophy of pyloric sphincter leads to obstruction

Palpable olive mass in epigastric region and nonbilious vomiting (2-6 weeks)

Firstborn males

hypokalemic, hypochloremic metabolic alkalosis (vomiting)

Surgical incision


Describe the development of the pancreas. What is annular pancreas? Results? What is pancreatic divisum? Results? Describe the development of the spleen.

Derived from foregut. Ventral pancreatic buds lead to uncinate process and main pancreatic duct. Dorsal leads to body, tail, isthmus, and accessory duct. Both lead to head.

Annular: Ventral pancreatic duct encircles 2nd part of duodenum leading to obstruction/narrowing

divisum: failure of buds to fuse at 8 weeks. Common. Usually asymp. but may cause chronic abdom. pain and pancreatitis

Spleen: mesentery of stomach (mesodermal) but is supplied by celiac artery.


What are the retroperitoneal structures? Generally what do they include? Specifically? What happens if they're injured?

GI structures that lack mesentery and non gi structures

Blood or gas in RP space if injured


Duodenum (2-4)
Pancreas (except tail)
Colon (ascending and descending)
Rectum (part)


What does the falciform ligament connect? What structures are contained in it? What abou hepatoduodenal ligament? What is the pringle maneuver? What about gastrohepatic? What about gastrocolic? Gastrosplenic? Splenorenal?


LIver to abdominal anterior wall
ligamentum teres hepatis (fetal umb. vein)


liver to duod
portal triad
Pinched to control bleeding


liver to lesser curv. of stomach
gastric arteries


greater curvature and transverse colon


greater curv. and spleen
short gastrics, left gastroepiploic


spleen to poster abdominal wall
splenic artery and vein, tail of pancreas


What are the 4 layers of the gut wall? What are included in each one? How are ulcers different than erosions? What is the frequncy of basal electric rhythm in the stomach? duod? ileum? What are some unique histological characteristics of the esoph, stom, duod, jej, ileum, and colon?

Mucosa=epithelium, lamina propria, muscularis mucosa

Submucosa=submucosal nerve plexus (meissner), secretes fluid (glands)

Muscularis externa=myenteric nerve plexus (auerbach), motility, inner circ. and outer long.

Serosa (intraperitoneal)/adventitia (RP)

Ulcers=submucosa, inner or outer musc. layer
Erosions=only mucosa

stomach=3 waves/min
duod=12 waves/min
Ileum: 8-9 waves/min

esoph: nonkeratinized stratified squamous epithelium

stomach: gastric glands

duod: vill and microvilli (crypts of lieberkuhn); brunners glands (secrete HCO3)

jej: plicae circulares (folds) and crypts of lieber

ileum: peyers patches, plicae circulares (proximal), and crypts of lieber. most goblet cells of small int.

Colon: crypts but no villi, abundant goblet cells; haustra, taenia coli


How can GI arteries be differentiated from non GI arteries? What are the branches of the abdominal aorta in order sup to inf.

GI=anterior branches

Non GI=Lateral branching

Left and right inferior phrenic
Celiac trunk
Left middle suprarenal
Left/right renal
Testicular/ovarian artery
Median sacral artery
left/right common iliac
External/internal iliac


What structures does the celiac artery provide? At what vert. level does it come off? What parasymp innervation do these structures receive? Same questions for SMA and IMA


Pharynx and lower esophagus to proximal duodenum; liver, gallbladder, pancreas, spleen



Distal duod. to prox. 2/3 of transverse colon



Distal 1/3 of transverse to upper portion of rectum



Describe the branches of the celiac trunk in order? What do they supply? Which branches have poor anastomoses? Strong ones?

Left gastric (esophogeal branch) run along less curv. and anastomose with right gastric

splenic artery (short gastric, left gastroepiploic (run along greater curv. and anastomose w/ right gastroepiploic)) runs behind stomach to spleen

Common hepatic artery (gastroduodenal artery (ant. sup. pancreaticoduodenal artery, right gastroepiploic, post. sup. pancreaticoduod. artery), hepatic artery proper (right gastric artery))


Describe the 3 portosystemic shunts including location, clinical sign, and vessels involved. What is TIPS. Describe it.

esophagus: esophageal varices; left gastric to esophageal veins

umbilicus: caput medusae; paraumbilical to small epigastric veins of the anterior abdom wall

rectum: anorectal varices; superior rectal to middle and inferior rectal

TIPS: transjugular intrahepatic portosystemic shunt between portal vein and hepatic vein


Where is the pectinate (dentate) line? What pathologies occur above the line? What is the blood supply? Venous drainage? Lymph drainage? Same questions for below line? What is the difference between internal and external hemorrhoids? Describe an anal fissure?

Endoderm meets ectoderm


internal hemorrh, adenocarcin

superior rectal artery (IMA)

Superior rectal vein (portal)

Internal iliac nodes


ext. hemorrh, squamous cell CA, anal fissures

inferior rectal artery (internal pudendal)

inferior rectal vein (int. pudendal to internal iliac to IVC)

superficial inguinal nodes

Int. hemorr: visceral innervation; not painful
ext: somatic innervation: painful if thrombosed

Anal fissure: tear in anal mucosa below the pectinate line

Pain while Pooping; blood on toilet Paper. Located Posteriorly due to Poor Perfusion


Describe the anatomy of the liver. What are zones 1-3? What are some pathologies in each? What are kupffer cells? What is the space of disse? What cells are there? Why are they significant?

Portal vein, hepatic artery, and bile ducts run together.

Sinusoids come off from portal vein. Sinusoids are lined by hepatocytes. The apical surface of hepatocytes faces bile caniculi, the basal faces the sinusoids.

The space between the hepatocytes and the sinusoids is called space of disse. It contains ito cells which store fat but during certain pathologies can become myofibroblasts leading to cirrhosis.

The flow of the bile ductules and the sinusoids is opposite.

The sinusoids drain inito central veins which drain into the hepatic vein.

Kupffer cells are specialized macrophages

Zone I-periportal zone
affected first by viral hep
ingested toxins (cocaine)

zone II-intermediate zone
Yellow fever

Zone III-pericentral vein (centrilobular zone):
affected 1st by ischemia
cytochrome p450 sytems
metabolic toxins
alcoholic hep


Describe the biliary tree. What can happen to gallstones that reach the ampulla of vater? What can happen with some tumors that arise in the head of the pancreas?

They can bause cholangitis and pancreatitis

They can only obstruct common bile duct alone and thus only cause painless jaundice

Cystic duct from gallbladder combine with the common hepatic duct (from left and right hepatic ducts) to form the common bile duct which enters the 2nd part of the duod. at the ampulla of vater with the main pancreatic duct. The sphincter of oddi surrounds the common bile duct at the ampulla.


How is the femoral region organized? What is contained int he femoral triangle? What is the femoral sheath? What does it contain?

Sheath: fascial tube 3-4cm below inguinal ligament.
Femoral vein, artery, and canal (deep ing. LNs) but not the femoral nerve.

Ring: vein, artery and nerve

lateral to medial to find your NAVEL

nerve, artery, vein, empty, lymph


What are the 4 layers of the abdom wall that the inguinal canal runs through? What are they called in the spermatic cord? What are the vessels and ligaments that are in the abdom. wall? Where does the inguinal ligament run?

Deep to super

transversalis fascia (internal spermatic fascia)
transversus abdominis (none)
internal oblique (cremasteric muscle and fascia)
External oblique (external spermatic fascia)

Lat. to med
Inferior epigastric, medial umbilical, median umbilical

Pubic tubercle to ant. sup. iliac spine


What is a hernia? What are 4 kinds?

A protrusion of peritoneum through an opening, usually a site of weakness

indirect inguinal
direct inguinal
femoral hernia


Describe a diaphr. hernia? What can cause it? Which side does it usually occur on? What are some common kinds?

Abdom. structures enter thorax

Cong. defect or trauma. Left side (no liver)

Hiatal hernia: stomach through esophageal hiatus
Sliding hiatal hernia (most common): GE junction moves up (hourglass)
paraesophogeal hernia: GE junction normal. Fundus protrudes into thorax to the side of the esophagus


Decribe an indirect inguinal hernia. When does it occur? Why? Gender? What is it covered by? Location?

Goes through internal inguinal ring and superficial ring and into scrotum.

Enters lateral to the inf. epigastric artery

Infants=failure of processus vaginalis to close


all 3 layers of spermatic fascia


Decribe a direct inguinal hernia. When does it occur? Why? Gender? What is it covered by? Location?

Protrudes through hesselbach triangle (inf. epigastric vessels, lateral border of rectus abdominis, and inguinal ligament). Bulges directly through abdominal wall.

External inguinal ring only. External spermatic fascia only.

Older men


Decribe a femoral hernia. Gender? What is it the leading cause of? Location?

below inguinal ligament through femoral canal below and lateral to pubic tubercle


Bowel incarceration.