Gastrointestinal Tract II

Question 1

Where is the most common site for colorectal cancer?

Answer 1

rectosigmoid junction

Question 2

Identify the arterial branches that supply the colon

Answer 2

IMA: inferior mesenteric artery

SMA: superior mesenteric artery

ICA: ileocecal artery

Question 3

What is it called when a portion of the GI tract is surgically exeralized?

Why might this be performed?

Answer 3

colostomy

needing to protect the distal large intestine after surger or to decompress the bowel if an obstruction is about to cause perforation

Question 4

What is the major difference between the colon and rectum?

What plane does the rectum transverse?

The rectum is derived from which parts of the fetal gut?

Answer 4

the rectum does not have taenia coli or haustra

rectum drops from abdominal cavity to pelvic cavity

hindgut and proctodeum

Question 5

Identify the arterial branches that supply the rectum

Answer 5

Question 6

What are the 2 types of serous membranes of the abdominal cavity? How are they different? How are they the same?

Answer 6

Parietal peritoneum: lines wall of abdominal cavity

visceral peritoneum: encloses viscera in abdominal cavity

They are continuous with each other

Question 7

What are key difference between structuers that are intraperitoneal and vs. structures that are retroperitoneal?

What does it mean for something to be secondarily retroperitoneal?

Answer 7

• intraperitoneal: entirely enclosed in visceral peritoneum
  
  • always have a mesentery
    
    • this allows it to be more mobile
• retroperitoneal:
  
  • does not have a mesentery
    
    • more stationary
• secondarily retroperitoneal means that it changes from embryo to adult

Question 8

Fill in the indicated parts of the table

Answer 8

Question 9

What are the 2 components of the lesser omentum? Where do they attach? Together they perform what functions?

Answer 9

omentum is double peritoneal layer attached to the stomach

• Hepatogastric ligament
  
  • lever to stomach
• hepatoduodenal ligament
  
  • liver to duodenum
• Function
  
  • transmit L & R gastric vessels
  • Frm anterior wall of lesser sac

Question 10

What are the 3 portions of the greater omentum? Where do they attach? What are their functions?

Answer 10

• gastrophrenic ligament
  
  • diaphragm to stomach
• gastrosplenic ligament
  
  • spleen to stomach
• gastrocolic ligament
  
  • transverse colon to stomach
  • folds down and then back up
    
    • transmits L & R gastroepiploic vessels
    • adheres to inflammation

Question 11

What is the function of mesentaries?

Idenfity the attachment points for the following mesentaries:

Mesentery Proper

Transverse Mesocolon

Sigmoid mesocolon

Mesoappendix

Answer 11

connects organ with parietal peritoneum

• mesentery proper
  
  • jejunum & ileum
  • transmits superior mesenteric artery & intestinal branches
• transverse mesocolon
  
  • transverse colon (continuation of gastrocolic ligament)
  • transmits middle colic vessels
• Sigmoid mesocolon
  
  • sigmoid colon
  • transmits sigmoid vessels
• Mesoappendix
  
  • appendix
  • transmits appendicular vessels

Question 12

What are the two potential spaces created through the peritoneal cavity? Boundaries?

Answer 12

• lesser sac
  
  • lesser omentum
  • stomach
  • greater omentum
  • transverse colon
  • transverse mesocolon
  • parietal peritoneum between them
  • liver
• greater sac
  
  • everything else

Question 13

What is the openign between the greater and lesser sac?

Answer 13

epiploic foramen

throgh duodenal portion of lesser omentum and inferior vena cava b

Question 14

What are the 3 unpaired branches given off by the abdominal aorta and their respective branches?

Answer 14

• Abdominal aorta
  
  • Celiac Trunk
    
    • Left Gastric (stomach (lesser omentum))
      
      • esophageal branch (abdominal esophagus)
    • Spleinc
      
      • dosal pancreatic artery
      • short gastric
      • left gastroeploic artery (greater curvature)
    • Comon hepatic
      
      • right gastric
      • proper hepatic
      • gastroduodenal
        
        • righr gastroepiploic (greater omentum)
        • supraduodenal (first/second part of duodenum)
        • superior pancreaticoduodenal (pancreas and duodenum)
          
          • anterior and posterior one
  • Superior Mesenteric Artery (midgut)
    
    • inferior pancreaticoduodenal
      
      • anterior/posterior ones
    • middle colic (transverse mesocolon)
    • right colic (retroperitoneal)
    • ileocolic
      
      • cecal
      • apendicular
    • intestinal (jejunal or ileal)
  • Inferior Mesenteric Artery (hindgut)
    
    • left colic (descending colon)
    • sigmoid (multiple)
    • superior rectal

Question 15

Veins that drain the abominal cavity pass through which organ before draining into which structure?

Answer 15

portal vein enters the liver to drain into the inferior vena cava

Question 16

The GI tract drains into which lymphatic structures?

Answer 16

preaortic lymph nodes (celiac, superior mesenteric, inferior mesenteric)

efferent vessels from these nodes together with lumbar trunks form cisterna cyli

Question 17

Identify the indicated branches of the inferior mesenteric artery

Answer 17

Question 18

Identify the indicated branches of the superior mesenteric artery

Answer 18

Question 19

Identify the 3 branches of the celiac trunk

Answer 19

Question 20

Identify the branches of the splenic artery

Answer 20

Question 21

Identify the indicated branches of the common hepatic artery

Answer 21