Download Superior mesenteric artery

Esophagus
Length:- 10 inches = 25 cm
Length of the abdominal part:- 0.5 inch = 1.25 cm
Relations:A- Anteriorly:1- Left lobe of liver
2- Left vagus N.
B- Posteriorly:1- Left crus of diaphragm
2- Left vagus N.
Blood supply:A- Arterial supply:- Branches from left gastric A.
B- Venous drainage:- Into left gastric V. → Into portal V.
Lymph drainage:- To left gastric L.Ns.
Nerve supply:1- Parasympathetic:- Anterior & posterior gastric Ns. = Left & right vagus Ns.
2- Sympathetic:- From thoracic part of sympathetic trunk
N.B.
1- Esophageal opening of diaphragm is an opening through the right crus
2- Esophagus enters the right side of stomach
3- Gastro-esophageal sphincter:- In the form of circular muscle layer at the lower end of esophagus
- It isn’t an anatomical sphincter = It is a Physiological sphincter
- Its closure is controlled by vagi
Stomach
Parts:1- Fundus:- Above the cardiac orifice
2- Body:- Extends between
a- Level of cardiac orifice
b- Level of incisura angularis
3- Pyloric antrum:- Between
a- Incisura angularis
b- Pylorus
4- Pylorus:- One inch long
- Its cavity is called pyloric canal
- Its muscular wall is called pyloric sphincter
Relations:A- Anteriorly:1- Anterior abdominal wall
2- Diaphragm
3- Left lobe of liver
4- Left costal margin
5- Left lung & pleura
B- Posterior relations = stomach bed:- Formed by
1- Pancreas
2- Splenic Artery
3- Spleen
4- Left kidney
5- Left suprarenal gland
6- Transverse colon
7- Transverse mesocolon
8- Diaphragm
9- Lesser sac
Blood supply:A- Arterial supply:1- Left gastric A.:- From celiac trunk
- Runs along lesser curvature
- Supplies the lower 1/3 of esophagus & upper right part of stomach
2- Right gastric A.:- From hepatic artery
- Runs along lesser curvature
- Supplies the lower right part of stomach
3- Short gastric A.:- From splenic A.
- Supply the fundus
4- Left gastro-epiploic A.:- From splenic A.
- Supplies stomach along upper part of greater curvature
5- Right gastro-epiploic A.:- From gastro-duodenal A. that is a branch of hepatic A.
- Supplies stomach along lower part of greater curvature
B- Venous drainage:1- Left gastric vein:To portal V.
2- Right gastric vein:To *
*
3- Short gastric Vs.:To splenic V.
4- Left gastro-epiploic V.:To *
*
5- Right gastro-epiploic vein:- To superior mesenteric V.
Lymph drainage:A- Lymph vessels pass with the As. to reach
1- Right & left gastric L.Ns.
2- Right & left gastro-epiploic L.Ns.
3- Short gastric L.Ns.
B- Then to celiac L.Ns.
Nerve supply:A- Parasympathetic nerve supply:- From right & left vagi
- Secretomotor to gastric glands, motor to muscles of stomach but
inhibitory to pyloric sphincter
B- Sympathetic supply:- Form celiac plexus
- Motor to pyloric sphincter
C- Pain transmitting nerve fibers:- Pass with the sympathetic fibers
Peritoneal covering:- completely covered by peritoneum except for bare area of the stomach
Peritoneal folds and ligaments:1- Greater omentum:- Connects the greater curvature with the transverse colon
2- Lesser omentum:- Connects the lesser curvature with the liver
3- Gastro-splenic ligament:- Connects the fundus with the spleen
4- Gastro-phrenic ligament:- Connects the fundus with the diaphragm
N.B.
1- Capacity of stomach = 1500 mL
2- Shape of stomach
a- J-shaped stomach = Vertical:- In tall thin persons
b- Steer-horn stomach = High & transverse:- In short obese persons
3- Steer horn = ‫قرن الثور‬
4- Openings of stomach:a- Cardiac orifice
b- Pyloric orifice
5- Stomach is relatively fixed at its ends by very mobile in between
6- Incisura angularis = Constant notch in the lower part of lesser curvature
7- Fundus contains gases
8- Pylorus is the most tubular part of stomach
9- Lesser curvature of stomach
a- It is the right border of stomach
b- Suspended to the liver by lesser omentum
10- Peritoneal ligaments & folds attached to the greater curvature of stomach
a- Gastro-splenic ligament:- Attached to its upper part & to spleen
b- Greater omentum:- Attached to its lower part & to transverse colon
11- Pyloric sphincter:- Anatomical & physiological
- Circular muscle fibers
12- Pylorus:- Lies on transpyloric plane
- Can be recognized by a constriction on its surface
13- Rugae = Mucosal folds of stomach:- Mainly longitudinal
14- Muscle fibers of stomach are longitudinal, transverse & oblique
15- Left gastric A. supplies
a- Lower 1/3 of esophagus
b- Upper right part of stomach
16- Left gastro-epiploic A. & short gastric As. arise from splenic A. at the
hilum → Then pass through gastro-splenic ligament
Small intestine
Parts:1- Duodenum
2- Jejunum
3- Ileum
Duodenum
Shape:- C-shaped
Length:- 10 inches = 25 cm
Position:- Retroperitoneal (fixed to the posterior abdominal
wall) except the 1st one inch that is mobile
Parts:1- First
= 2 inches
2- Second = 3 inches
3- Third = 4 inches
4- Fourth = 1 inch
Blood supply:A- Arterial supply:1- Superior pancreaticoduodenal artery:- Branch of gastroduodenal A that is a branch of hepatic A.
- Supplies the upper half
2- Inferior pancreaticoduodenal artery:- Branch of superior mesenteric A.
- Supplies the lower half
B- Venous drainage:1- Superior pancreaticoduodenal V.:- Drains into portal V.
2- Inferior pancreaticoduodenal V.:- Drains into superior mesenteric V.
Lymph drainage:- Lymphatics follow As.
1- Upward through pancreatico-duodenal L.Ns. → To gastro-duodenal
L.Ns → To celiac L.Ns.
2- Downwards through pancreatico-duodenal L.Ns → To superior
mesenteric L.Ns.
Nerve supply:- By celiac & superior mesenteric plexuses that consist of
1- Sympathetic fibers
2- Parasympathetic fibers:- From vagus nerves
Peritoneal covering:1- The 1st one inch:- Resembles the stomach
- The peritoneum covers its anterior & posterior surfaces
- Lesser omentum is attached to its upper border
- Greater omentum is attached to its lower border
2- The remainder:- Retro-peritoneal
- The peritoneum covers its anterior surface partially
Directions of the 4 parts:A- First part:- Begins at pylorus
- Runs upward, backward & to the right on transpyloric plane
- At the level of 1st lumbar vertebra
B- Second part:- Vertical
- On the right side of 2nd & 3rd lumbar vertebrae
C- Third part:- Horizontal
- Directed to the left
- Along subcostal plane
- Passes in front of vertebral column
D- Fourth part:- Upward & to the left
- Ends at duodeno-jejunal flexure
Relations of duodenum
Relations of the 1st part
A- Anteriorly:1- Quadrate lobe of liver 2- Gall bladder
B- Posteriorly:1- Portal V.
4- Lesser sac:- Behind the 1st one inch
2- Bile duct
5- Gastroduodenal A.
3- I.V.C.
C- Superiorly:- Epiploic foramen
D- Inferiorly:- Head of pancreas
Relations of the 2nd part
Anteriorly:1- Right lobe of liver
2- Transverse colon
B- Posteriorly:1- Hilum of right kidney
C- Laterally:1- Ascending colon
2- Right colic flexure
D- Medially:1- Head of pancreas
2- Bile duct
3- Coils of small intestine
4- Fundus of gall bladder
2- Right ureter
3- Right lobe of liver
3- Main pancreatic duct
Relations of the 3rd part
A- Anteriorly:1- The root of mesentery of small intestine
2- Superior mesenteric vessels in the root of mesentery of small intestine
3- Coils of jejunum
B- Posteriorly:1- Right ureter
3- I.V.C.
2- Right psoas major
4- Aorta
C- Superiorly:- Head of pancreas
D- Inferiorly:- Coils of jejunum
Relations of the 4th part
Anteriorly:1- Beginning of the root of mesentery of small intestine
2- Coils of jejunum
B- Posteriorly:1- Left margin of aorta
2- Medial border of left psoas major
N.B.
1- Lesser sac is behind
a- Stomach
b- First one inch of duodenum
c- Lesser omentum
d- Greater omentum
2- Duodenum lies in epigastric & umbilical regions
3- Ampulla of Vater opens into the medial border of 2nd part of duodenum
4- Plicae circularis = Circular mucosal folds = In duodenum, jejunum & ileum
5- Major & minor duodenal papillae = Rounded elevations in the medial
wall of 2nd part of duodenum:- Produced by …………. & ……….
6- Minor duodenal papilla is 2 cm above the major one
7- Duodeno-jejunal flexure is held in position by a peritoneal fold called
ligament of Treitz
8- Ligament of Treitz is attached to
a- Right crus of diaphragm
b- Duodeno-jejunal flexure
Jejunum & ileum
Arterial supply:A- Jejunum:- Supplied by jejunal branches of S.M.A.
B- Ileum:- Supplied by
1- Ileal branches of S.M.A.
2- Ileocolic A.:- From S.M.A.
Venous drainage:- The same as arterial supply
A- Jejunum:- Drained by jejunal Vs. to S.M.V.
B- Ileum:- Drained by
1- Ileal Vs. to S.M.V.
2- Ileocolic V.:- To S.M.V.
Lymph drainage:- To intermediate mesenteric L.Ns. →
Then to superior mesenteric L.Ns.
Nerve supply:- By superior mesenteric plexus that consists of
1- Sympathetic fibers
2- Parasympathetic fibers:- From vagus nerves
Differences between jejunum and ileum
1- Length
2- Site
3- Mesentery
4- Wall
5- Lumen
6- Colour
7- Vessels
8- Mesenteric fat
9- Plicae
circularis
10- Payer's
patches
11- Windows
12- Intestinal villi
Jejunum
The upper 2/5 of the free
part of small intestine
- 240 cm
In the upper part of
peritoneal cavity
Attached to posterior
abdominal wall above &
to the left of aorta
Thicker
Wider
Redder
a- 1 – 2 rows of arcades
b- Long terminal vessels
Lesser
Larger & more numerous
Absent
Present
Larger and more numerous
Ileum
- The lower 3/5
- 360 cm
a- In the lower part of
peritoneal cavity
b- In the pelvis
Attached to posterior
abdominal wall below & to the
right of aorta
a- 3 – 4 rows
b- Short terminal vessels
Greater amount
a- In the upper part:- Smaller
& fewer than in jejunum
b- In the lower part:- Absent
Present in the antimesenteric
border of lower part of ileum
Absent
Small and few
N.B.
1- Length of jejunum + Ileum = 20 feet = 6 meters
2- Jejunum begins at duodeno-jejunal flexure
3- Ileum end at ileo-cecal junction
4- Coils of jejunum & ileum
- Freely mobile
- Attached to the posterior abdominal wall by the mesentery of small intestine
5- Mesentery of small intestine has 2 edges
1- Long free edge:- Contains jejunum & ileum
2- Short attached edge = The root:- Continuous with parietal
peritoneum on the posterior abdominal wall
6- The root of mesentery of small intestine extends
a- From the left side of 2nd lumbar vertebra
b- To the region of right sacro-iliac joint
7- Superior mesenteric L.Ns. lie around the origin of S.M.A.
8- Peyer’s patches = Aggregations of lymphoid tissue
Differences between large and small
intestine
A- External differences:Small intestine
Large intestine
1- Mobility
Mobile except
duodenum
Mobile except
ascending &
descending colon
2- Caliber
Smaller
Larger
3- Mesentery
Has a mesentery
except duodenum
Transverse colon,
sigmoid colon &
appendix have
mesenteries
4- Longitudinal
muscle layer
Forms a continuous
layer around small
intestine = No teniae
coli
Collected into 3
longitudinal bands
(Teniae coli) except in
appendix, rectum &
anal canal
Absent
5- Appendices
epiploica = Fatty tags
attached to the walls
6- Saccules in the
walls
Absent → Smooth
wall
Present
present
B- Internal differences:-
Plicae circularis
Intestinal villi
Peyer’s patches
Small intestine
Present
Present
Present
Large intestine
Absent
Absent
Absent
Caecum
Position:- In the right iliac fossa
Length:- 6 cm
Peritoneal covering:- Completely covered by peritoneum → Mobile
Caecal peritoneal recesses:1- Retrocecal recess
2- Superior ileocaecal recess
3- Inferior
*
*
Relations:A- Anteriorly:1- Anterior abdominal wall
2- Coils of small intestine
3- Part of greater omentum
B- Posteriorly:1- Psoas major
2- Iliacus
2- Femoral N.
3- Lateral cutaneous femoral nerve
4- Appendix
C- Medially:- Appendix
Arterial supply:- Anterior and posterior cecal arteries that
are branches of ileocolic artery that is a branch of S.M.A.
Venous drainage:- By anterior & posterior ileo-cecal Vs. →
To ileo-colic V. → To S.M.V.
Lymph drainage:- To mesenteric L.Ns. → To superior
mesenteric L.Ns.
Nerve supply:- By superior mesenteric plexus that consists of
1- Sympathetic fibers
2- Parasympathetic fibers:- From vagus nerves
Appendix
Length:- 8 – 13 cm
Site:- In right iliac fossa
- Its base lies deep to McBurney’s point
- McBurney’s point is at the junction between the latera 1/3 & medial
2/3 of a line drawn between
a- A.S.I.S.
b- Umbilicus
Attachment to caecum:- Its base is attached to the posteromedial aspect of caecum. One inch below the ileocaecal junction
Positions of the tip:1- In the pelvis:- Common
2- Behind caecum:- Common
3- Lateral to caecum
4- In front of or behind terminal part of ileum
Peritoneal covering:- Completely covered by peritoneum
- Has a mesentery (mesoappendix)
Arterial supply:- Appendicular artery that is a branch of posterior caecal A.
Venous drainage:- Appendicular V. → To posterior caecal V.
Lymph drainage:- To 1 – 2 L.Ns. in meso-appendix → To
superior mesenteric L.Ns.
Nerve supply:- By superior mesenteric plexus that consists of
1- Sympathetic fibers
2- Parasympathetic fibers:- From vagus nerves
3- Sensory afferent fibers:- Accompany the sympathetic fibers →
Reach 10th thoracic segment of spinal cord
Surface anatomy:- The base of appendix is represented by McBurney's point
- McBurney's point is a point at the junction between the lateral 1/3 and
medial 2/3 of a line drawn between the right A.S.I.S. and umbilicus
N.B.
1- Caecum lies below the ileocecal junction
2- Ileocecal junction is at the junction between caecum & ascending colon
3- Ileocaecal opening is guarded by 2 horizontal mucosal folds (Called
ileocecal valve)
3- Teniae coli converge at the base of appendix
4- No teniae coli in appendix, rectum nor anal canal
6- Meso-appendix is attached to the mesentery of small intestine
7- Appendicular vessels & nerves pass through meso-appendix
8- Base of appendix can be found by identifying the teniae coli of caecum
→ Trace these teniae coli → They converge towards the base of appendix
Ascending and descending colon
Length
Peritoneal
covering
Anterior
relations
Posterior
relations
Ascending colon
Descending colon
13 cm
25 cm
Peritoneum covers the anterior surface and the sides → Binds the
ascending & descending colon to the posterior abdominal wall
1- Anterior abdominal wall
2- Coils of small intestine
3- Greater omentum
1- Iliacus muscle
2- Iliac crest
3- Quadratus lumborum
4- Origin of transversus
abdominis
5- Right kidney
6- Iliohypogastric N.
7- Ilioiguinal N.
1- …………
2- …………
3- …………
4- …………
5- …………
6- …………
7- …………
8- Left psoas major
9- Femoral N.
10- Lateral cutaneous nerve of the
thigh
By branches of I.M.A.:1- Right colic A.
2- Ileo-colic A.
Right colic & Ileocolic Vs.
Venous
→ To S.M.V.
drainage
To colic L.Ns. → To
Lymph
superior mesenteric L.Ns.
drainage
Nerve supply By superior mesenteric
plexus that consists of
1- Sympathetic fibers
2- Parasympathetic fibers
from vagus nerves
Arterial
supply
By branches of I.M.A.:1- Left colic A.
2- Sigmoid As.
Left colic & Sigmoid Vs. → To
I.M.V.
To colic L.Ns. → To inferior
mesenteric L.Ns.
By inferior mesenteric plexus that
consists of
1- Sympathetic fibers
2- Parasympathetic fibers from
pelvic splanchnic nerves
Transverse colon
Length:- 38 cm
Relations:Anteriorly:1- Greater omentum
2- Anterior abdominal wall (Umbilical & hypogastric regions)
Posteriorly:1- Second part of duodenum
2- Head of pancreas
3- Coils of jejunum & ileum
Arterial supply:A- Proximal 2/3:- Supplied by middle colic A. that is a branch of S.M.A.
B- Distal 1/3:- Supplied by left colic A. that is a branch of I.M.A
Venous drainage:- The same as the arterial supply
A- Proximal 2/3:- drained by middle colic V. that drains to S.M.V.
B- Distal 1/3:- Drained by left colic V. that drains to I.M.V.
Lymph drainage:A- Proximal 2/3:- Drain to colic L.Ns. → Then to superior mesenteric L.Ns.
B- Distal 1/3:- Drain to colic L.Ns. → Then to inferior mesenteric L.Ns.
Nerve supply:A- Proximal 2/3:- The same as ascending colon
B- Distal 1/3:- The same as descending colon
Peritoneum of transverse colon
1- Transverse mesocolon:- Attached to
a- Anterior border of pancreas
b- Upper border of transverse colon
2- Posterior layers of greater omentum:- Attached to lower
border of transverse colon
Peritoneal covering:- Completely covered by peritoneum except its first part where the peritoneum covers its anterior
surface only but the posterior surface lies directly on the 2nd part of duodenum and head of pancreas
N.B.
1- Descending colon ends at the pelvic brim by continuation as pelvic colon
2- Ascending colon is in front of the lower pole
of right kidney.
3- Descending colon is in front of the lateral border
of left K.
4- Left colic flexure is
a- Higher than the right one
b- Suspended from diaphragm by phrenico-colic ligament
5- Transverse colon is suspended from pancreas by transverse mesocolon
Celiac artery
Beginning:- From the commencement of abdominal aorta at the level
of last thoracic vertebra
Branches:1- Left gastric A.
2- Splenic A.
3- Hepatic A.
Splenic artery
Course:- Originates from celiac trunk → Runs to the left on the upper
border of pancreas behind the stomach → In front of left kidney →Passes
through lieno-renal ligament → Enters the hilum of spleen
Branches:1- Pancreatic branches
2- Left gastro-epiploic A.
3- Short gastric As.:- 5-6 in number
Hepatic artery
Course:- Arises from celiac trunk → Runs to the right &→ Ascends in the
right free margin of lesser omentum (In front of portal V. & to the left of bile
duct) → Ends at porta hepatis by dividing into right & left branches
Branches:1- Right gastric A.
2- Gastro-duodenal A.:- Descends behind first part of duodenum then
divides into
a- Right gastro-epiploic A.
b- Superior pancreatico-duodenal A.
3- Terminal branches:a- Right branch:- Gives the cystic A.
b- Left branch
Superior mesenteric artery
Course:- Begins from the anterior surface of abdominal aorta
at the level of 1st lumbar vertebra → Descends in front of the
3rd part of duodenum → Descends in the root of mesentery of
small intestine → Ends at the ileocaecal junction by anastomosis
with the ileal branch of ileocolic A.
Course and relations:- descends in front of the uncinate process
of pancreas
Branches:1- Inferior pancreaticoduodenal artery:- Single or double
- Passes between head of pancreas & 3rd part of duodenum
- Supplies pancreas & duodenum
2- Middle colic artery:- Passes through the transverse mesocolon
- Supplies the right 2/3 of transverse colon
- Divides into right and left branches
3- Right colic artery:- Supplies ascending colon (the upper 2/3) and right colic flexure
- Divides into ascending & descending branches
- Usually a branch of ileocolic A.
4- Jejunal and ileal branches
- 12 – 15 in number
- Supply jejunum & ileum
- Form arcades
5- Ileocolic artery that divides into
A- Superior branch:- Anastomoses with the right colic A.
B- Inferior branch:- Anastomoses with the end of S.M.A. & gives
1- anterior cecal A.
2- posterior cecal A.:- Gives appendicular A.
Collectively:- Aorta → S.M.A. → Ileocolic A. → Inferior division →
Posterior cecal A. → Appendicular A.
Inferior mesenteric artery
Course:- Begins from the anterior surface of abdominal aorta 3.8 cm
above its bifurcation → Descends downward & to the left → Ends by
passing in front of the left common iliac artery → continues as the
superior rectal artery in the medial limb of sigmoid mesocolon
Branches:1- Left colic artery:-Supplies the left 1/3 of transverse colon , left colic flexure & upper
part of descending colon
-Divides into ascending & descending branches
2- Sigmoid arteries:-
- 2 – 3 in number
-Supply the sigmoid colon and lower part of descending colon
3- Superior rectal artery:- It is the continuation of I.M.A. as it crosses in front of left C.I.A.
- Supplies the rectum and upper 1/2 of anal canal
Marginal artery
Definition:- Anastomosis of colic As. around the concave margin of
large intestine
Formation:1- Anastomosis between
a- Ileal branch of ileocolic A. = Inferior branch of ileocolic A.
b- S.M.A.
2- Anastomosis between
a- Superior branch of ileocolic A.
b- Descending branch of right colic A.
3- Anastomosis between
a- Ascending branch of right colic A.
b- Right branch of middle colic A.
4- Anastomosis between
a- Left branch of middle colic A.
b- Ascending branch of left colic A.
5- Anastomosis between
a- Descending branch of left colic A.
b- First sigmoid A.
6- Anastomosis between
a- Sigmoid As.
b- Superior rectal A.
Splenic vein
Course:- Begins at hilum of spleen by the union of several
veins → Passes to the right inside splenico-renal ligament →
Runs behind tail & body of pancreas → Ends behind the neck of
pancreas by uniting with S.M.V. to form portal V.
Tributaries:1- Inferior mesenteric V.
2- Pancreatic Vs.
3- Short gastric Vs.
4- Left gastro-epiploic V.
Inferior mesenteric vein
Course:- Begins as a continuation of superior rectal A. → Ascends on
the left side of inferior mesenteric A. & duodeno-jejunal flexure → Joins
the splenic V. behind the body of pancreas
Tributaries:1- Sigmoid Vs.
2- Left colic V.
3- Superior rectal V.
Superior mesenteric vein
Course:- Begins at ileo-cecal junction → Ascends in the root
of mesentery of small intestine on the posterior abdominal wall
→ Passes in front of 3rd part of duodenum → Passes behind
neck of pancreas → Ends behind the neck of pancreas by
uniting with ………… to form ……….
Tributaries:1- Inferior pancreatico-duodenal V.
2- Right gastro-epiploic V.
3- Jejunal Vs.
4- Ileal Vs.
5- Ileo-colic V.
6- Right colic V.
7- Middle colic V.
N.B.
1- Celiac trunk = Artery of the foregut
2- Foregut includes
1- Lower 1/3 of esophagus
2- Stomach
3- First part of duodenum
4- Upper ½ of 2nd part of duodenum
3- Midgut includes
1- Lower ½ of 2nd part of duodenum
2- Third & fourth parts of duodenum
3- Jejunum & ileum
4- Caecum & appendix
5- Ascending colon
6- Proximal 2/3
4- Hindgut includes
1- Distal 1/3 of transverse colon
2- Descending colon
3- Sigmoid colon
4- Rectum
5- Upper ½ of anal canal
5- Celiac trunk
a- Surrounded by celiac plexus
b- Behind lesser sac
6- Gastric As.
a- Between the 2 layers of lesser omentum
b- Run along the lesser curvature of stomach
c- Anastomose together
7- Gastro-epiploic As.
a- Between the 2 layers of greater omentum
b- Run along the greater curvature of stomach
c- Anastomose together
8- Short gastric As. anastomose with the left gastric & left gastro-epiploic As.
9- Right gastric A. arises from hepatic A. at the upper border of pylorus
10- Superior pancreatico-duodenal A. runs between the head of pancreas
& 2nd part of duodenum
11- Superior rectal A.:- Descends behind the rectum
- Anastomoses with the middle & inferior rectal As.
2- S.M.V. is on the right side of S.M.A.
Veins of the portal system
1- Portal vein
2- Splenic vein
3- Superior mesenteric vein
4- Inferior mesenteric vein
Portal vein
Length:- 2 inches = 5 cm
Course:- Begins behind the neck of pancreas by the union of
S.M.V. and splenic V. → Ascends behind the 1st part of
duodenum → Ascends in the free margin of lesser omentum in
front of epiploic foramen → Ends at porta hepatis by dividing
into right and left branches
Tributaries:1- splenic vein
2- superior mesenteric vein
3- right gastric vein
4- left gastric vein
5- cystic vein:- to the right branch of portal vein.
6- Inferior mesenteric V. drains into the splenic V.
7- paraumbilical veins:- connect the veins of anterior abdominal wall with the left branch of portal vein
Sites of portosystemic anastomosis
1- In the lower 1/3 of esophagus:A- Between
1- Esophageal tributaries of azygos vein (systemic tributaries)
2- Esophageal tributaries of left gastric vein (portal tributaries)
B- Significance = in portal hypertension → esophageal varices.
2- Halfway down the anal canal:A- Between
1- Superior rectal vein (portal tributaries)
2- Middle & inferior rectal Vs. that drain into internal iliac &
internal pudendal Vs. (systemic tributaries)
B- Significance = in portal hypertension → piles = hemorrhoids
3- Paraumblical Vs.:A- Connect
1- Left branch of portal V.
With 2- Superficial veins of anterior abdominal wall (Systemic
tributaries)
B- Significance = in portal hypertension → caput medusae
4- Anastomosis between
A- Veins of ascending colon, descending colon, duodenum, pancreas &
liver (Portal tributaries)
B- Renal, lumbar & phrenic Vs. (Systemic tributaries)
N.B.
1- Portal hepatic vein = Portal vein
2- Portal V. drains
a- Abdominal part of G.I.T. (From lower 1/3 of esophagus to upper ½
of anal canal)
b- Spleen
c- Pancreas
d- Gall bladder
3- Cystic V. drains into either
a- To right branch of portal V.
b- Directly to the liver
4- Para-umbilical Vs. accompany ligamentum teres inside the
lower margin of falciform ligament
5- Left gastric V. drains the stomach and lower 1/3 of esophagus.
6- The systemic veins = the veins that drain into I.V.C. and S.V.C.
7- Caput medusae = Varicose veins radiating from umbilicus
8- Portal vein and its tributaries have no valves