Duodenum, Small Intestine

Question 1

What is responsible for suspension of the duodenojejunal flexure?

Answer 1

the suspensory ligament of the duodenum (ligament of Treitz)

Question 2

What is the ampulla of Vater?

Answer 2

segment where the path of the bile duct and the main pancreatic duct are shared before entering the 2nd part of the duodenum

Question 3

What marks the transition between the foregut and the midgut?

Answer 3

the major duodenal papilla

Question 4

What is the sphincter of Oddi?

Answer 4

a muscular sphincter surrounding the major duodenal papilla

Question 5

The jejunum and ileum are connected to the posterior abdominal wall via what?

Answer 5

the mesentery proper and they are therefore intraperitoneal

Question 6

What is McBurney’s point?

Answer 6

roughly approximates the position of the ileocecal junction and is used during physical exam to diagnose appendicitis (in response to pressure applied at this point)McBurney’s point lies on a straight line drawn between the anterior superior iliac spine (ASIS) and the umbilicus and divides the line into its inferior 1/3 and superior 2/3.

Question 7

What are the two structures caught in the nutcracker relationship formed by the acuteangle between the SMA and the abdominal aorta?

Answer 7

The left renal vein and the 3rd part of the duodenum

Question 8

What is Nutcracker syndrome?

Answer 8

entrapment of the L renal vein. Entrapment of the duodenum is called superior mesenteric artery syndrome and is very rare.

Question 9

Blood supply proximal to the duodenal papilla is from what?

Answer 9

the celiac trunkDistal to the papilla, the blood supply is from the superior mesenteric artery.

Question 10

What part of the pancreas lies anterior to the SMA and SMV?

Answer 10

the neck

Question 11

The tail is the continuation of the body into what?

Answer 11

the lienorenal ligament. As such, it is the only part of the pancreas that is peritoneal.

Question 12

The jejunum comprises the proximal ___ of the small intestine; the ileum comprises the distal ___ of the small intestine

Answer 12

2/5; 3/5

Question 13

Why is it not necessary true that loops of jejunum are always higher in the abdominal cavity than loops of ileum?

Answer 13

Both are quite mobile in the abdomenWhat is true is that the root of the mesentary of the jejunum is on the left side of the midline and that of the ileum is to the right of the midline.

Question 14

Which has thicker walls, the jejunum or the ileum?

Answer 14

jejunum (more absorptive surface)

Question 15

Which has a larger diameter lumen, the jejunum or the ileum?

Answer 15

jejunum

Question 16

Which has longer straight arteries, the jejunum or the ileum?

Answer 16

jejunum

Question 17

Which has more mesenteric fat, the jejunum or the ileum?

Answer 17

ileum

Question 18

Which has more elaborate circular mucosal folds (Plicae circulares), the jejunum or the ileum?

Answer 18

jejunum

Question 19

Which has more prominent/complex arterial arcades, the jejunum or the ileum?

Answer 19

ileumNote that there are one or two tiers of anastomotic arches in the mesentary of the jejunum whereas there are up to five or size levels of arterial arches in the mesoileum.

Question 20

The Right Colic Flexure is aka?

Answer 20

The Hepatic Flexure

Question 21

The Left Colic Flexure is aka?

Answer 21

The Splenic Flexure

Question 22

The presence of tenia coli and haustra in the large intestine are due to what?

Answer 22

due to uneven distribution of smooth muscle in the wall of the colon

Question 23

Notes on haustra

Answer 23

They are due to uneven distribution of the circular smooth muscle layer. Where there is a concentration of circular smooth muscle, the diameter of the colon is narrowed. This is the narrow part between each haustra.

Question 24

Notes on tenia coli

Answer 24

Tenia coli are due to uneven distribution of the longitudinal smooth muscle layer. The longitudinal smooth muscle is concentrated in the tenia colie so that the exterior of the colon there is made smooth. The tenia coli have been likened to a shiny highway running length of the colon. There are three tenia coli.

Question 25

What parts of the colon are peritoneal?

Answer 25

transverse and sigmoid

Question 26

The transverse colon is at what vertebral level?

Answer 26

transpyloric plane

Question 27

What are the main branches off the superior mesenteric artery?

Answer 27

A. Inferior pancreaticoduodenal aa. B. Intestinal aa. (jejunal and ileal aa.) C. Middle colic a.D. Right colic a.E. Ileolcolic a.

Question 28

What are the main branches off the inferior mesenteric artery?

Answer 28

A. Left colic a.B. Sigmoidal aa.C. Superior rectal a.

Question 29

The marginal artery is an anastomotic loop along in interior margins of the colon. It is made up of the branches of what arteries?

Answer 29

the right, middle, and left colic aa. and the sigmoidal aa.

Question 30

T or F. The origin of the IMA lies posterior to the third part of the duodenum

Answer 30

TWith respect to surface anatomy, the origin of the IMA and the third part of the duodenum lie 2 cm (3/4”) above the transumbilical plane. The bifurcation of the abdominal aorta into R & L common iliac arteries lies the same distance, 2 cm, below the transumbilical plane.

Question 31

T or F. The tributaries of the superior and inferior mesenteric veins have the same names and pattern as the branches of the SMA and IMA

Answer 31

T

Question 32

What is the portal vein is defined as?

Answer 32

being formed by the junction of the SMV and splenic vein (that’s why it is aka the splenic-mesenteric confluence). This junction lies in the transpyloric plane, posterior to the neck of the pancreas.NOTE: the veins corresponding to primary branches of the celiac trunk, notably the L & R gastric veins, the L & R gastroepiploic veins and the splenic vein are direct tributaries to the portal vein