Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Duodenum Lecture PPT
DUODENUM
Dr. Swati Suman
Assistant Professor
Dept of Anatomy
NMCH,Jamuhar
DUODENUM
?
INTRODUCTION
?
Duodenal recesses
?
RELATIONS
?
Blood supply
?
Interior of duodenum
?
Lymphatic drainage
?
Suspensory ligaments
?
Nerve supply
of duodenum
?
Applied anatomy
Duodenum -shortest, widest &
most fixed
part of the small intestine.
Extent: Pylorus to duodenojejunal
flexure.
Shape: ` C' shaped
Location: above the level of umbilicus,
opposite 1st , 2nd & 3rd lumbar
vertebrae.
Parts:
1. Superior (1st ) part: 5 cm (2 inches)
long
2. Descending (2nd ) part: 7.5 cm (3
inches)
3. Horizontal (3rd ) part: 10 cm (4
inches)
4. Ascending (4th ) part: 2.5 cm (1
inch)
FIRST PART
FIRST PART
Relation:
Anteriorly: Quadrate lobe of liver & GB.
Posteriorly: Portal vein, gastroduodenal
artery & common bile duct .
Superiorly: Epiploic foramen
Inferiorly: Head & neck of pancreas.
Features
?Initial 2.5 cm- no circular folds in mucous
membrane - duodenal cap
?Proximal 2.5 cm is movable.
?1st Part : site for duodenal ulcer-
because
it is supplied by end arteries and receives
acidic chyme from stomach.
SECOND PART
SECOND PART
Relations :
Anteriorly:
? Gallbladder,
? Right lobe of liver,
? Transverse colon, root of transverse
mesocolon,
? coils of small intestine.
Posteriorly:
? Right kidney, right renal vessels,
? Right edge of IVC
? Right psoas major muscle.
Medially:
Head of the pancreas.
Laterally:
Right colic flexure & right lobe of liver.
THIRD PART
Third Part:
Relations
Anteriorly:
Root of the mesentery, superior mesenteric
vessels & coils of jejunum.
Posteriorly:
Right psoas major,
right ureter,
IVC, abdominal aorta & right gonadal vessels.
Superiorly:
Head of the pancreas & uncinate process.
Inferiorly:
Coils of the jejunum.
Applied Anatomy:
Obstruction of the third part -pressure of
superior mesentric artery over aorta
FOURTH PART
Fourth part:
Relations
Anteriorly: Transverse colon and
transverse mesocolon.
Posteriorly: Left psoas major muscle,
left sympathetic chain, left gonadal
vessels & inferiormesenteric vein.
Superiorly: Body of the pancreas.
To the left: Left kidney and left ureter.
To the right: Upper part of root of
mesentery.
INTERIOR OF THE DUODENUM
circular folds (valves of
Kerckring)- begin in second
part and become large &
closely set below of major
duodenal papilla.
1. Major duodenal papilla:
2. Minor duodenal papilla:
3. Arch of plica semicircularis:
4. Plica longitudinalis:
1. Major duodenal papilla: Conical
projection on posteromedial wall ,
8?10 cm distal to pylorus.
Site for opening of common
hepatopancreatic duct
2. Minor duodenal papilla: small
conical projection, situate 6-8 cm
distal pylorus.
Accessory pancreatic duct opens
on its summit.
3. Arch of plica semicircularis:
forms an arch above major
duodenal papilla like a hood
4. Plica longitudinalis: vertical
tortuous fold of mucous
membrane extending downward
from major
duodenal papilla.
SUSPENSORY MUSCLE OF DUODENUM
(LIGAMENT OF TREITZ)
? Fibromuscular band- suspends duodenojejunal
flexure from right crus of the diaphragm.
Attachment:
?Upper end- attached to right crus of diaphragm
? Lower end- attached to posterior surface of
duodenojejunal flexure, third & fourth part of
duodenum
made up of :
(a) Striated muscle fibres - upper part.
(b) Elastic fibres - middle part.
(c ) Smooth muscle fibres -lower part
Function:
Fixes duodenojejunal flexure & prevents it from
being dragged down by weight of small intestine.
Applied Anatomy:
?Normally its contraction
increases the angle of
duodenojejunal flexure.
?Sometimes it is attached only
to flexure, and then its
contraction may narrow the
angle of the flexure, causing
partial obstruction of the gut.
DUODENAL RECESSES(FOSSAE)
ARTERIAL SUPPLY
VENOUS DRAINAGE
The veins correspond to the
arteries & drain into
the splenic, superior mesenteric,
and portal veins.
LYMPHATIC DRAINAGE
Most lymph vessels drain to
pancreaticoduodenal
nodes. coeliac and superior
mesenteric lymph
nodes intestinal lymph trunk
cisterna chyli.
NERVE SUPPLY
Sympathetic nerves :T9?T10
segments of the spinal cord
Parasympathetic nerves : vagus
through coeliac and superior
mesenteric plexuses. From these
plexuses, fibres run along arteries
of the duodenum to supply it
APPLIED ANATOMY
Kissing ulcer-1st part of duodenum
presents ulcer on the anterior and
posterior walls .
If anterior wall perforate:
content enter grater sac.
If posterior wall perforates: erodes
gastroduodenal artery leading to
fatal haemorrhage.
If posterior wall perforates: contents
enter the lesser sac.
APPLIED ANATOMY
Peptic Ulcer: occur in site of pepsin & HCL secreation - lower end of
oeosphagus, stomach, 1st part of duodenum, meckel's diverticulum
Blood group O- duodenal ulcer.
Duodenal ulcer:
-epigastric pain ? due to hunger
-pain relieved by food
-pain shows periodicity for number of
weeks.
-pain wakes patient at night at 2-3 am
Gastric ulcer:
- epigastric pain ? due to hunger
-pain is made worse by food ? pt. become
anorexic and shows weight loss.
-periodicity is less marked
This post was last modified on 30 November 2021