Duodenum Flashcards
(17 cards)
Duodenum
Shortest widest most fixed part of small intestine
Extends from pylorus to duodenojejunal flexure
Location
Curved around head of pancreas
Above the level of umbilicus
Opp L1to l3
On posterior abdominal wall
(Least accessible for clinical studies due to deep location)
Lenght
25 cm
Parts
1st superior part 2 inches 5cm
2nd part 3 inches 7.5 cm
3rd part 4 inches 10cm
4th part 1inch 2.5 cm
Peritoneal relation
Mostly retroperitoneal anterior surface covered with peritoneum
Fixed
At 2 ends they are suspended by folds of peritoneum: mobile
1st part 2.5 cm proximal is movable attachment to lesser omentum above greater omentum below
2nd part anterior surface near the middle is not covered by peritoneum as it is related tocolon
3edpart at median plane is not covered due to superior mesenteric vessels and root of mesentry
1st part course
At pylorus
Passes backwards
Upwards
To right
Meets second part at superior duodenal flexure
Peculiarities of 1st part
.Proximal 2.5 cmintraperiotenal
Distal retroperitoneal
. Mobile and distensible
. Does not have circular mucosal folds
.only part to receive end arteries
. develops from forgut supplied by coeliac trunk
. duodenal cap seen barium meal radiography
. Common site for duodenal ulcers
Visceral relation of 1st part
Anteriorly
Quadrate lobe of liver and gallbladder
Visceral relation of 1st part
Anteriorly: Quadrate lobe of liver and gallbladder
Posteriorly: portal vein bile duct gastroduodenal artery
Superiorly: epiploic foramen
Inferiorly head and neck of pancreas
Second part course
7.5cm 3inches long
Begins from superior duodenal flexure
Goes downwards
Reaches L3
Curves to left at inferior duodenal flexure
Second part peculiarities
Gives opening to main bile duct and accessory pancreatic duct
Fixed
retroperitoneal
Upper part develops by foregut
Lower midgut
Dual blood supply by sup and inf pancreaticoduodenal artery
Supplied by double rows of vasa recta
Visceral relation of 2nd part
ANTERIORLY right lobe of liver , transvere colony root of Transvers mesocolon coils if small intestine
POSTERIORLY: anterior surface of right kidney right renal vessels,right edge of ivc , ryt psoas major muscle
MEDIALLY :head of pancreas
LATERALLY :ryt colic flexure
Interior of second part
1.Plicae circulares closely packed circular mucosal folds
2. Major duodenal papillae : conical
elevation on posteromedial wall
Abt 8-10 cm distal to pylorus
Main pancreatic duct opens here
3. Minor duodenal papillae: small projection
6-8 cm distal to pylorus
2cm proximal to major duodenal papillae
4. Plicae semicirculares muscosal fold arching above M.D.P resembles monks hood
5.Plica longitudinalis vertical mucosal folds extending downwards from M.D.P
3rd part course
10cmlong
Begins at inf duodenal flexure
On ryt of lower border of L3
Passes horizontally
Slightly upwards
Infront of ivc
Joins 4th infront of abdominal aorts
Visceral relation of 3rd part
ANTERIORLY superior mesenteric vessels, root of mesentry
POSTERIORLY right ureter right psoas major ,right gonadal vessels, IVC abdominal aorta
Superiorly head of pancreas and uncinate process
Inferiorly coils of jejunum
Fourth part course
2.5 cm long
Runs upwards till the upper border of L2
Then turns forward
Continues with jejunum at duodenojejunal flexure
Visceral relation of 4th part
ANTERIORLY Transvers colon, Transvers mesocolon lessee sac if stomach
POSTERIORLY left sympathetic chain,left renal artery left Gondal artery, inferior mesenteric artery
TO RYT : attachment of upper part of root of mesentry
TO LEFT: left kidney and left ureter
SUPERIORLY body of pancreas
