For medical, nursing, and physiotherapy undergraduates, and postgraduates

1. PORTAL VEIN

2. INTRODUCTION
 It drains the blood from the abdominal part
of alimentary tract except the Lower part of
Rectum and Anal canal.
 It also drains the veins from Spleen, Pancreas
and Gall Bladder.
 These veins unite to form the Trunk of Portal
vein.

3. PECULARITIES
1. Begin like veins from capillary plexus and
ends like arteries by dividing into Hepatic
Sinusoids.
2. It also conveys absorbed products of digested
food.
3. Portal vein and tributaries are devoid of
valves.
4. It acts as Reservoir of blood. About 1/3rd of
blood can be stored.

4. PECULARITIES
5. ‘ Streamline flow.’
6. Out of 1500 ml of blood circulating through
Liver per minute ;
• 1200 ml is provided by Portal vein
• 300 ml by Hepatic artery.

5. FORMATION
 It is formed by the union of Superior
Mesenteric vein and Splenic vein behind the
neck of pancreas in front of Inferior Venacava
at the level of vertebra L2.
 Its 8 cm long and 2 cm in width.

8. COURSE
 Its course is divided into :
1. Extra-hepatic part
2. Intra-hepatic part

9. EXTRA-HEPATIC PART
 It measures 8 cm in length and 2 cm in width.
 From its formation, it passes upwards, slightly
to the right behind the neck of Pancreas and
1st part of Duodenum.
 Enters Right Free margin of Lesser Omentum,
reaches Porta Hepatis and divides into Right
and Left branches.

10. EXTRA-HEPATIC PART
 Blood flow in Portal vein is slow.
 Right branch is shorter, more vertical and
receives Cystic vein.
 Left branch is longer and more oblique and it
receives Para-umbilical vein.

11. EXTRA-HEPATIC PART
 Blood from Superior mesenteric vein drains
into Right lobe through Right branch of Portal
vein.
 Blood from Splenic vein and Inferior
Mesenteric vein drains into Left lobe through
Left branch of Portal vein.
 This is called ‘Steamline flow’.

12. RELATIONS
INFRA-DUODENAL PART
In Front : Neck of Pancreas
Behind : Inferior Venacava.
On Right side : Bile duct

14. RETRO-DUODENAL PART
In Front : 1st part of Duodenum separated by
Bile duct and Gastro-duodenal artery.
Behind : Inferior Vena-cava

16. SUPRA-DUODENAL PART
WITHIN LESSER OMENTUM
In Front and to the Right : Bile duct
In Front and to the Left : Hepatic artery
surrounded by Hepatic plexus of nerves and
Lymphatics.
Behind : Inferior Vena-cava

17. SUPRA-DUODENAL PART
AT THE PORTA HEPATIS
From before backwards :
1. Right and left Hepatic ducts
2. Right and left branches of Hepatic artery.
3. Right and left branches of Portal vein.

18. INTRA-HEPATIC PART
 Right and Left branches of Portal vein
supplies physiological right and left lobes of
Liver.
 Branches of Portal vein accompanied by
branches of Hepatic artery and Bile Ductules
pass through the Portal Canals in the Inter-
lobular spaces of Liver.

19. INTRA-HEPATIC PART
 Portal Radicles of the canal convey the blood
to the Hepatic Sinusoids through the Inlet
Venules.
 Hepatic sinusoids deliver the blood to Central
Veins.
 Central veins unite to form Sub-lobular veins.
 Sub-lobular veins unite to form Hepatic
veins.
 Hepatic veins drain into IVC.

20. TRIBUTARIES
 Formative veins :
1. Superior Mesenteric Vein
2. Splenic Vein
 Directly received by Trunk of Portal vein :
1. Right Gastric Vein
2. Left Gastric Vein
 Received by divisions of Portal vein :
1. Cystic vein
2. Para-umbilical vein

22. OCCASIONAL TRIBUTARIES
1. Inferior Mesenteric Vein
2. Right Gastro-epiploic Vein
3. Pre-pyloric Vein

23. PORTA CAVAL ANASTOMOSIS
Sl.
No.
Name of site Portal system Systemic
1. At the lower end of
oesophagus
Oesophageal tributaries
of Left gastric vein
Oesophageal tributaries of Hemi-
azygous vein.
2. At the lower end of
rectum and anal canal
Superior rectal vein Middle and inferior rectal veins.
3. At the umbilicus Para-umbilical vein From above : Superior Epigastric
Vein and Lateral thoracic vein.
From below : Inferior and Superior
Epigastric veins
From sides : Posterior Intercostal
and Lumbar veins.
4. Behind the Peritoneum
of Posterior Abdominal
wall
Splenic and Colic veins Left Renal veins through a number
of small veins known as ‘Veins of
Retzius.’
5. At the Bare area of liver Portal radicles of Liver Diaphragmatic veins through a
number of small veins passing
through loose areolar tissue.

24. PORTA CAVAL ANASTOMOSIS
Sl.
No.
Name of site Portal system Systemic
6. In the Falciform ligament Para-umbilical vein Diaphragmatic veins through
“Accessory portal system of sappy.”
7. At the fissure of
Ligamentum Venosum
Left branch of portal vein Inferior Venacava through Ductus
venosus

25. APPLIED ANATOMY
1. Portal pressure
2. Portal hypertension
3. Causes of Portal hypertension
4. Effects of Portal hypertension