small intestine

Question 1

duodenum

Answer 1

the shortest part of the small intestine
25cm in length
C-shaped around the head of the pancreas
extends from the pylorus (gastroduodenal junction) to the jejunum (duodenojejunal junction)

situated in the umbilical and gastric region

mostly retroperitoneal and fixed except the first 2 cm

Question 2

parts of duodenum

Answer 2

first ((superior)) at L1
Second ((descending)) L2-L3
Third ((horizontal)) at L3
Fourth ((ascending)) L3

DUODOJEJUNNAL JUNCTION IS AT L2 THAT TAKES A FORM OF ACUTE ANGLE THE DUODNOJEJUNAL FLEXURE

Question 3

jejnum

Answer 3

the lower 3/5th and to the right, often entering the pelvis and terminates at the ileocecal junction

Question 4

illeum

Answer 4

ileum is the upper 2/5th

Question 5

jejunum and ileum is suspended by the

Answer 5

mesentry

Question 6

1ST superior part of duodenum

Answer 6

ascends posteriorly from the pyloris on the transpyloric plane

its retroperitoneal except first 2 cm
first two cm lies between peritoneal folds of greater omenta and is mobile
the mucos membrane of the duodenum is thrown into numerous circular folds -> plicae circulares
the first 2cm walls is smooth and form a duodenal gap radiographically

Question 7

relations of the first part

Answer 7

anteriorly is the gallbladder and the quadrate lobe of the liver

superiorly is the opening of the omental foramen

posteriorly is the lesser sac first inch, bile duct, gastroduodenal artery and poral vein

inferiorly is the head of the pancreas

Question 8

relations of the second part

Answer 8

anteriorly is the fundus of the gallbladder, right lobe of the liver, transverse colon (transverse mesocolon)

posteriorly is the right uterer and right renal hilum

laterally is the right colic flexure or hepatic flexure of colon and right lobe of the liver

medially is the head of the pancreas, bile duct and main pancreatic duct

Question 9

inferior of the second part

Answer 9

major duodenal papilla

minor duodenal papilla

Question 10

relations of the third part

Answer 10

anteriorly is covered by peritoneum except the root of the mesentry
superior mesentric vessels contained within the root and coils the jejunum

posterioly right psoas major, right urter, IVC, abdominal aorta

superiorly is the head of the pancreas

inferiorly coils the jejunum

Question 11

fourth part of the duodenum

Answer 11

runs superiorly from the front of the aorta to the duodenojejunal flexure

the ligament of treitz supports the duodenojejunal flexure

Question 12

duodenal ulcer

Answer 12

the ulcer of the posterior wall of the first part may perforate the gastroduodenal artery resulting in severe hemorrhage into the peritoneal cavity

anterior wall ulcer may perforate into the greater sac

this may permit content to enter the peritoneal cavity causing peritonitis

Question 13

paraduodenal hernia

Answer 13

paraduodenal fold and fossa lie to the left of the ascending duodenum part
if a loop of the intestine enters this fossa it can strangulate

Question 14

jejenum and illeum extend from

Answer 14

duojejunal junction to the illiocecal junction

Question 15

mesentry of the small intestine

Answer 15

fan shaped double fold that attaches the jejunum and illeum to the posterior abdominal wall

Question 16

root of mesentry

Answer 16

15 cm long that extends obliguelly in the posteior abdominal wall from duojejunal junction (l2) to the right sacroiliac joint

Question 17

root of mesentry crosses the following structures

Answer 17

3rd part of duodenum
abdominal aorta
IVC
right ureter
right psoas muscle 
right gonadal vessels

Question 18

what are the contents of the mesentry of the small intestine

Answer 18

jejunum and illleum 
superior mesentric blood vessels
lymph nodes 
fat
autonomic nerves

Question 19

differences between jejunum and illeum

Answer 19

jejunum is shorter , constitutes the upper 2/5th and illium is lower 3/5

jejunum is above and to the left and is in the left upper quadrant

Question 20

structure of the wall of the jejunum

Answer 20

wide and thicker than illeum since it has pliccae circulares

Question 21

structure of wall of illeum

Answer 21

thinner wall than jejunum

plicae circulares gradually disappear so its absent distally

Question 22

what is a plicae circulares

Answer 22

permanent infoldings of the mucos membrane to increase the surface area for absorbtion

Question 23

arrangment of blood vessels in jejunum and illeum

Answer 23

jejunum few arcades and long vasa recta

illeum many arcades and short vesa recta

Question 24

has more aggregations of lymphoid tissue in its wall that can be observed macroscopically

Answer 24

illeum

Question 25

fat in mesentry of jejunum and illeum

Answer 25

jejunum: scantry near the intestinal wall
illeum: more fat present throughout the mesentry

Question 26

foregut supplied by the

Answer 26

celiac trunk

Question 27

midgut supplied by

Answer 27

superior mesentric arteries

Question 28

hindgut supplied by the

Answer 28

inferior mesentric artery

Question 29

superior mesentric artery origin and course

Answer 29

origin: from abd aorta at L1
course: descends to the right behind the body and in front the uncinate process of the pancreas
crosses in front of the third part of the duodenum
enters the root of the mesentru of small intestine
ends at right illiac fossa anastomosiing w/ illeocecal branch

Question 30

branches of the superior mesentric artery

Answer 30

inferior pancreaticoduodenal artery
middle colic artery
right colic artery
illeocolic artery
jejunal arteriies 
illeal arteries

Question 31

superior mesentric vein

Answer 31

runs with the right mesentric artery in the root of mesenty and terminates to the neck of the pancreas where it unites with the splenic vein to form the portal vein