Download duodenum

ABDOMEN Ⅳ
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Objects
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• Go over the stomach and the liver
• The arteries and ligaments of stomach and liver
• Bile circulation
• Pancreas
• Small intestine
• Large intestine
•
•Dissection
Greater omentum & Lesser
omentum
Hepatogastric ligament
Hepatoduodenal ligament
Gastrophrenic ligament
Gastrosplenic ligament
Gastrocolic ligament
Visceral surface of liver
left lobe
right lobe
caudate lobe
quadrate lobe
Caudate lobe
left lobe
Quadrate
lobe
Right
lobe
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Liver
Porta hepatis
5 cm long, transversely across the “H”,
★ transverse fissure --
– Contents
• Right and left hepatic ducts
• Left and right branches of proper hepatic
artery
• Left and right branches of hepatic portal
vein
• Nerves and lymphatic vessels
– These structures are surrounded by connective
tissue and is called
“hepatic pedicle”
4 types vessels of liver
• Blood supply of liver:
1. proper hepatic artery( ← hepatic A← celiac trunk ← aorta)
2. hepatic portal vein
A dual BLOOD supply: the portal vein supply for75%(dominant) ,
The arterial supply account for 25%(lesser)
1. Proper hepatic artery
Celiac trunk → common hepatic A →proper
hepatic A → right & left branches
→
2. Hepatic portal vein
General features
•
the union of superior mesenteric vein
SMV and splenic vein
•
passing through the lesser omentum to
the porta hepatis, divides into right and
left branches
•
Has no valves in hepatic portal system
•
Drains blood from GI tract(capillaries)
to hepatic sinusoid(capillaries) : the
lower end of esophagus to the upper
end of anal canal, pancreas, gall bladder,
bile ducts and spleen
2. Hepatic portal vein
Tributaries of hepatic portal v.
1. Superior mesenteric v. SMV
2. Inferior mesenteric v. IMV
3. Splenic v.
4. Left gastric v.
5. Right gastric v.
6. Cystic v.
7. Paraumbilical v.
Portal- Caval venous anastomoses
1. Site at the esophagus
left gastric vein → esophageal venous plexus →
esophageal vein → hemiazygos vein → superior vena
cava
Esophageal varices,---bleeding
2. At rectum
splenic vein → inferior mesenteric vein → superior rectal
vein → rectal venous plexus → inferior rectal and anal
veins → internal iliac vein → inferior vena cava
• Hemorroid --- Hemorrage
Portal hypertension
Portal- Caval venous anastomoses
3. At paraumbilical venous rete
paraumbilical vein→periumbilical venous rete→
thoracoepigastric and superior epigastric vein →intercostal vein--superior vena cava
Caput medusa
4.retroperitoneal anastomosis
the retroperitoneal branches of the colic veins
pancreaticoduodenal veins -----the lumbar veins, twigs of colic
veins (portal) anastomosing with systemic retroperitoneal
veins
Intestinal bleeding
pancreaticoduodenal veins
3 Intrahepatic bile duct

4 hepatic veins
The segments of the liver
– bases upon the principal divisions
of the proper hepatic artery and
accompanying hepatic ducts and
hepatic portal vein－
“Glisson system” .
– The hepatic vein do not follow the
same pattern and vary: their main
tributaries run rather
intersegmental.
Couinaud segments 8
by controversial
★ Biliary duct and gallbladder
• ★ Consists of
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Gallbladder,
Left and right hepatic ducts
Common hepatic duct
Common bile duct
Enters the wall of descending part of duodenum
obliquely where joins the main pancreatic
duct to form the hepatopancreatic ampulla
•
Opens at the major duodenal papilla
★ Gallbladder
• ★ Position
– Lies in fossa for gallbladder on visceral
surface of liver
• ★ Four parts
1. Fundus of gallbladder
protrude below the inferior margin of the liver,
behind the point where the lateral margin
of the right rectus abdominis meets the
costal arch (Murphy’ point)
2.Body of gallbladder
3.Neck of gallbladder
4. Cystic duct
• Function: stores and concentrates bile
★ Biliary duct system
• Left and right hepatic ducts
unite outside of liver to form
common hepatic duct
• common hepatic duct
• Cystic duct joins common hepatic
duct to form common bile duct
★ Biliary duct system
• Hepatopancreatic ampulla (Vater)
– Common bile duct and pancreatic duct run
obliquely through the wall of the descending
part of duodenum ,unite to form the
hepatopancreatic ampulla --- rounded by
sphincter of hepatopancreatic
ampulla (Oddi), has sphincteric muscle for
regulating flow, opens at the major
duodenal papilla
Obstruction of the biliary system results in the
clinic condition of jaundice (yellow skin) .
Cystohepatic triangle
Calot’s Triangle
• Boundaries
– Common hepatic duct on the
left
– Cystic duct on the right
– Liver superiorly
• Content: cystic artery
Divisions of common bile duct
Divisions 4
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•
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•
Supraduodenal segment
Retroduodenal segment
Pancreatic segment
Intraduodenal segment
• Hepatogastric ligament
• Hepatoduodenal
ligament
★ Bile circulation
Bile is secreted by the liver cells
Common hepatic duct
Right and left hepatic
ducts
Biliary
ductuli
Gallbladder (store, concentrate)
Cystic duct
When fat enters small intestine,
gallbladder contracts, sphincter of
hepatopancreatic ampulla relax
Common bile duct
Main
Pancreatic
duct
the hepatopancreatic ampulla
Major duodenal papilla
Duodenal cavity
Magnetic resonance cholangiopancreatography.
Pancreas
• Function
– The pancreas is both an exocrine
and an endocrine gland
– The exocrine portion of the gland
produces a secretion that
contains enzymes that are
capable of hydrolyzing proteins,
fats, and carbohydrates
– The endocrine portion of the
gland, the pancreatic islet,
produces the hormones insulin
and glucagons , play a key role in
carbohydrate metabolism
Pancreas
• Shape
– A soft yellowish gland
• Position
– Lies in epigastric and left
hypochondriac regions,
behind the peritoneum on the
posterior abdominal wall,
roughly at the level of of
L1~L2
Pancreas
•
Four parts
– Head--Lies within the C-shaped
curvature of duodenum.
• Uncinate process A
projection to the left from
the lower part of the head
behind the superior
mesenteric vessels.
– Neck--narrow part, overlies the
superior mesenteric vessels
and beginning of the portal
vein
– Body--triangular in cross
section, passes upward ang to
the left across the midline
– Tail--extends to the hilum of
spleen in the splenorenal
ligament
Pancreas
•
Pancreatic duct
– Main Pancreatic duct
• Begins at tail and throughout gland
• Joins common bile duct before entering descending part of
duodenum at major duodenal papilla
– Accessory pancreatic duct
• When present, drains head of pancreas separately
• Opens 2cm above main duct at lesser duodenal papilla
Blood supply of pancreas
Arteries
1.Mainly from splenic A
2.Superior pancreaticoduodenal a.(from gastroduodenal A)
– Inferior pancreaticoduodenal a.(from SMA)
Veins－ draining into superior mesenteric and splenic veins –potal vein.
CT scan of pancreas.
spleen
• lies posterolaterally against the
diaphragm and ribs 9 to 11 on the left
side of the body.
• Usually it is palpable only when
enlarged.
• Diaphragmatic surface
• Visceral surface
– Anteriorly－fundus of stomach
– Posteriorly－left suprarenal gland
and kidney
– Inferiorly－tail of pancreas and left
colic flexure
Ligaments of spleen
1.Gastrosplenic ligament －connects the fundus of stomach to
hilum of spleen.
the short gastric and left gastroepiploic vessels pass through it.
2. Splenorenal ligament －extends between the hilum of spleen
and left kidney.
The splenic artery and vein pass through it
3. Phrenicosplenic ligament
4. Splenocolic ligament
The Small Intestine
• About 6m long,
• Divided into
– Duodenum
– Jejunum
– Ileum
Duodenum
1. The major part of chemical digestion ,
extends from the pylorus to the
Ileum
ileocecal junction . Proteins are
broken down into small peptides and
amino acids before absorption.
2. permanent circular folds and villi
( villus ) for absorption .Each villus has
a network of capillaries (amino acids
and carbohydrates)and fine lymphatic
vessels called lacteals (lipids)close to
its surface.
jejunum
duodenum
Features:
1. 25cm long,the widest
and fixed part of
small intestine.
2. Pursue a C-shaped
course around the
head of pancreas.
3. 4 parts
Four parts
Duodenum
1.Superior part
5cm, L1 vertebrae
Superior duodenal flexure
2.Descending part
7~10cm, L2~3
3. Horizontal part
6~8cm,L3 to the left
4. Ascending part
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–
duodenojejunal flexure
Ligament of tretz
duodenum
1.superior part
Quadrate lobe of live
Gallbladder
Duodenal cap (radiography )
The beginning
2cm,intraperitoneal,mobile
Site of duodenal ulcer
duodenum
2. descending part
1.Major duodenal
papilla(opening)
hepatopancreatic ampulla
(Vater ampulla)--united of the bile and
pancreatic ducts
2.Minor duodenal papilla
duodenum
3.horizontal part
• Anteriorly
– Root of mesentery
– Superior mesenteric a. and v.
duodenum
ascending part
• Right — Head of pancreas and abdominal
aorta
• Left — left kidney and ureter
Suspensory muscle of duodenum
(ligament of Treitz)
composed of a skeletal muscle from
diaphragm , and a fibromuscular band
of smooth muscle from the
duodenum.
a surgical landmark, descends from the
right crus of diaphragm to duodenal
termination.
Blood supply of duodenum
• Arteries
– Superior pancreaticoduodenal
a.
– Inferior pancreaticoduodenal a.
• Veins－follow arteries, draining
directly into superior mesenteric
and hepatic portal veins
• Lymph drainadge
follow the arteries to celiac LN
• Nerve innervation:
superior mensenteric plexus
celiac plex
Jejunum and ilium
The jejunum and ileum
lies free in the abdomen.
They are attached to the
posterior abdominal wall
by the mesentery .
Intraperitoneal organ
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Jejunum and ileum
jejunum is shorter , emptier, more vascular (redder in vivo), more thickly walled .
Jejunum and ileum
Characteristic
Jejunum
Ileum
Position
Upper 2/5
Lower 3/5
caliber
2~4cm
2~3cm
Wall
Thicker and heavy
Thin and light
Circular folds
Large, tall and large
villi
low，sparse, less
abundant villi
Vascularity
Greater
Less
Colour
Deeper red
Paler
vasas recta
Arcades
Fat in
mensentery
Long
A few large loops
less
Short
Many short loops
more
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Mesentery
The mensentery
- suspends the small intestine
from the posterior abdominal
wall
-Broad and a fan-shaped;
arteries and veins between the
two layers of peritoneum
• Root of mesentery
– 15 cm long
– Directly obliquely run
from left side of L2
vertebra to right
sacroiliac joint
Middle colic a.
Inf. pancreaticodudenal a.
Right colic a.
Ileocolic a.
Appendicular a.
Blood supply of small intestine-------SMA
Superior
Mesenteric v.
Superior
mesenteric a.
Jejunal and ileal a.
large intestine
• Approximately 1.5m long,
• Five parts:
– Cecum
– Vermiform appendix
– Colon
– Rectum
– Anal Canal
Function: absorb excess water,compact chyme into semisolid stool;
store and accumulate until defecation
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Features：
Distinguished from small intestine by:
1.Teniae coli: 3 thickened longitudinal bands of
smooth muscles, begin at the base of appendix,at
rectosigmoid junction emerge with each other
2.haustra : sacculations of wall of the colon between the teniae
3. Omental appendices: small ,fatty, projections
haustra
of colon
Teniae coli
omental
appendices
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Hepatorenal recess
Paracolic gutters are formed by
the ascending and descending
colons
1.beginning of large intestine,
（一）Cecum 2.Blind intestinal pouch, 7.5*7.5cm
3. Lies in right iliac fossa.
4.Free and has no mensentery --- mobile cecum
The ileum enters the cecum obliquely, and partly invaginates
into it, forming the ileocecal valve－consists of two folds.
ileocecal
valve
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The cecum
Intussusception:
invagination of a tubular organ or part, the telescoping
of one section of the intestinal tract into a lower section, causing obstruction
Human Anatomy
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Appendix
1. a blind intestinal diverticulum,
2~20cm
2. mesoappendix: triangular
mesentery
3.the base of appendix ：
Lies deep to a point that 1/3 of
the way along the oblique line
joining the right anterior
superior iliac spine to the
umbilicus .(Mcburney’s point)
The
base of the appendix lies
at the point of convergence of
three teniae coli
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（二）vermiform appendix
position: very variable in position,
frequently lies in the retrocecal recess
or extend into the lesser pelvis.
Appendicitis: acute inflammation of
appendix, shows abdominal pain,
nausea,abdominal rigidity
appendectomy
appendicular perforation
orifice
appendix
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colon
1、ascending colon
2、transverse colon
3、descending colon
4、sigmoid colon
right colic flexure(hepatic)
left colic flexure(splenic)
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Inferior mesenteric v.
Inferior mesenteric a.
Left colic a.
Sigmoid a.
Superior rectal a.
Blood supply of large intestine-----IMA
Celiac trunk----- supplies the foregut
SMA----supplies the midgut
IMA--- hindgut
Marginal artery----the first arcades of a series of
anastomic arcades is continued by the ileocolic, right,
middle, left and sigmoid colic arteries ,form a
continuous arterial channel, so-called~ ;parallel and
extends the length of the colon
 Sigmoid colon
volvulus
an abnormal twisting of the intestines
causing obstruction
Human Anatomy
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The rectum
1. the pelvic part of digestive tract, at S3 vertebra
2. Not straight: lateral view “S” shape
sacral flexure of the rectum
anorectal flexure:(for fecal continence)
Human Anatomy
•Rectum
Blood supply
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anal canal
1.Teminal part of large intestine, 3
cm long, ends to anus
2.Surrounded by internal and
external anal sphincters
internal : involuntary sphincter,
surrounding superior 2/3
external: large voluntary sphincter,
forms a broad band on each side of the
inferior 2/3; has subcutaneous , superficial
and deep parts
fecal incontinence
Human Anatomy
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Anal canal
1. Internal structure
1) anal columns )
anal valves
anal sinuses
2) pectinate line
pile (hemorrhoid)
[examination per anus ]
Human Anatomy
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Coronary section through rectum
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Name the structures
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