Portal vein

PORTAL VEIN

Q. 1

True about valves in portal venous system?

 A

Present at the junction of superior mesentric artery with the splenic artery

 B

Within the portal vein only

 C

The whole system is valveless

 D

In the intrahepatic portion of portal vein.

Q. 1

True about valves in portal venous system?

 A

Present at the junction of superior mesentric artery with the splenic artery

 B

Within the portal vein only

 C

The whole system is valveless

 D

In the intrahepatic portion of portal vein.

Ans. C

Explanation:

The whole system is valveless 

  • Venous valves help in unidirectional blood flow in veins
  • The number of valves is greatest below the knee and decrease in number in the more proximal veins.
  • Valveless veins or venous sytem are
  • – Inferior vena Cava

– Common iliac veins

– Portal venous system

– Cranial sinuses


Q. 2

The Portal vein is formed?

 A

By the superior mesenteric vein

 B

By the splenic vein

 C

At the level of 2nd lumbar vertebra

 D

All of the above

Q. 2

The Portal vein is formed?

 A

By the superior mesenteric vein

 B

By the splenic vein

 C

At the level of 2nd lumbar vertebra

 D

All of the above

Ans. D

Explanation:

All of the above


Q. 3 The Normal Portal venous pressure is:
 A 4-6 mm Hg
 B 8-12 mm Hg
 C 26-30 mm Hg
 D 12-16 mm saline
Q. 3 The Normal Portal venous pressure is:
 A 4-6 mm Hg
 B 8-12 mm Hg
 C 26-30 mm Hg
 D 12-16 mm saline
Ans. B

Explanation:

8-12 mm Hg


Q. 4

In a patient with liver cirrhosis, where does portal vein obstruction occur?

 A

Portal vein

 B

Splenic vein

 C

Sinusoids

 D

Hepatic vein

Q. 4

In a patient with liver cirrhosis, where does portal vein obstruction occur?

 A

Portal vein

 B

Splenic vein

 C

Sinusoids

 D

Hepatic vein

Ans. C

Explanation:

In cirrhosis of the liver, portal vein obstruction occur at the level of sinusoids. In cirrhosis there is fibrosis of the liver resulting in architectural distortion with the formation of regenerative nodules. This results in a decrease in hepatocellular mass, its function, and an alteration of blood flow.

Complications of cirrhosis includes portal hypertension and its consequences (such as gastroesophageal variceal hemorrhage, splenomegaly, ascites), hepatic encephalopathy, spontaneous bacterial peritonitis (SBP), hepatorenal syndrome, and hepatocellular carcinoma.

Ref: Harrison’s Internal Medicine, 18th Edition, Page 2598, Chapter 308


Q. 5

Which of the following values indicate normal portal venous pressure?

 A

5 – 10 mm Hg

 B

10 – 15 mm Hg

 C

20 – 25 mm Hg

 D

25 – 30 mm Hg

Q. 5

Which of the following values indicate normal portal venous pressure?

 A

5 – 10 mm Hg

 B

10 – 15 mm Hg

 C

20 – 25 mm Hg

 D

25 – 30 mm Hg

Ans. A

Explanation:

Normal portal venous pressure is 5 – 10mmHg (10 – 15cm saline). Portal venous system contributes 75% of blood and 72% of oxygen supplied to the liver. Portal vein is formed by the confluence of superior mesenteric vein and splenic vein. In an average adult 1000-1500ml /min of portal venous blood is supplied to the liver.


Reference:
Schwartz’s Principles of Surgery 9e chapter 31.


Q. 6

Portal hypertension is defined as hepatic venous pressure gradient more than:

 A

1 mm Hg

 B

5 mm Hg

 C

10 mm Hg

 D

20 mm Hg

Q. 6

Portal hypertension is defined as hepatic venous pressure gradient more than:

 A

1 mm Hg

 B

5 mm Hg

 C

10 mm Hg

 D

20 mm Hg

Ans. B

Explanation:

Portal hypertension is defined as the elevation of the hepatic venous pressure gradient (HVPG) to >5 mmHg. Portal hypertension is caused by a combination of two simultaneously occurring hemodynamic processes.

Ref: Harrison’s principle of internal medicine 17th edition, chapter 302.


Q. 7

Which of the following statement regarding portal venous system is TRUE?

 A

Valves are present at the junction of superior mesenteric vein and splenic vein

 B

Whole system is valveless

 C

Valves are present in the intrahepatic system

 D

There are about 10-12 valves along the entire course

Q. 7

Which of the following statement regarding portal venous system is TRUE?

 A

Valves are present at the junction of superior mesenteric vein and splenic vein

 B

Whole system is valveless

 C

Valves are present in the intrahepatic system

 D

There are about 10-12 valves along the entire course

Ans. B

Explanation:

In adults, the portal vein and its tributaries have no valves. In fetal life and for a short postnatal period valves are demonstrable in its tributaries, but they usually atrophy. Rarely some persist in an atrophic form into adulthood.

Portal venous system comprises of portal vein and its 3 tributaries, splenic vein, superior and inferior mesenteric vein. Thses veins drain the blood from the intestinal tract, from the oesophagus to the rectum, from the spleen and pancreas to the liver. Portal vein carries 75% of total blood flow to the liver. Normal portal pressure is 5 – 10mmHg.


Q. 8

The portal venous system contributes approximately 75% of the blood and 72% of the oxygen supplied to the liver. Which of the following is TRUE about valves in portal venous system?

 A

Present at the junction of superior mesenteric artery with the splenic artery

 B

Within the portal vein only

 C

The whole system is valveless

 D

In the intrahepatic portion of portal vein

Q. 8

The portal venous system contributes approximately 75% of the blood and 72% of the oxygen supplied to the liver. Which of the following is TRUE about valves in portal venous system?

 A

Present at the junction of superior mesenteric artery with the splenic artery

 B

Within the portal vein only

 C

The whole system is valveless

 D

In the intrahepatic portion of portal vein

Ans. C

Explanation:

The portal venous system is without valves and drains blood from the spleen, pancreas, gall bladder, and abdominal portion of the alimentary tract into the liver. 

Tributaries of the portal vein communicate with veins draining directly into the systemic circulation. These communications occur at the gastroesophageal junction, anal canal, falciform ligament, splenic venous bed and left renal vein, and retroperitoneum.
  
 

Q. 9

Portal vein begins at the level of which vertebra?

 A

L2

 B

L4

 C

L5

 D

None of the above

Q. 9

Portal vein begins at the level of which vertebra?

 A

L2

 B

L4

 C

L5

 D

None of the above

Ans. A

Explanation:

The portal vein begins at the level of the second lumbar vertebra and is formed from the convergence of the superior mesenteric and splenic veins. It is 8 cm long and lies anterior to the inferior vena cava and posterior to the neck of the pancreas.


Q. 10

Which one of the following characterizes a portal system of blood vessels?

 A

The absence of a capillary bed, thus shunting arterial blood directly to venules

 B

A capillary bed supplied and drained by a larger, non-capillary vessel

 C

Two capillary beds connected by a larger blood vessel

 D

A continuous capillary bed that extends from one organ to another

Q. 10

Which one of the following characterizes a portal system of blood vessels?

 A

The absence of a capillary bed, thus shunting arterial blood directly to venules

 B

A capillary bed supplied and drained by a larger, non-capillary vessel

 C

Two capillary beds connected by a larger blood vessel

 D

A continuous capillary bed that extends from one organ to another

Ans. C

Explanation:

A portal system of blood circulation is defined as two capillary beds that are joined by an arterial or venous blood vessel. An example is the portal vein connecting the mucosal capillaries of the small intestine to the sinusoids (i.e., capillaries) of the liver. While capillary beds may connect parts of an organ (e.g., adrenal cortex, pancreatic islet), capillaries do not extend between organs.
 

Q. 11

Which of the following vessel provide maximum blood supply to the liver?

 A

Hepatic artery

 B

Portal vein

 C

Superior mesenteric artery

 D

None of the above

Q. 11

Which of the following vessel provide maximum blood supply to the liver?

 A

Hepatic artery

 B

Portal vein

 C

Superior mesenteric artery

 D

None of the above

Ans. B

Explanation:

70% of the blood to the liver is carried by portal vein. Hepatic artery carries 30% of the blood to liver. Hepatic artery provides oxygenated blood to the liver and portal vein brings venous blood rich in products of digestion. 


Q. 12

Which of the following is TRUE about portal vein?

 A

Formed by the superior mesenteric vein

 B

Formed by the splenic vein

 C

Situated deep to the hepatic artery and cystic duct

 D

All of the above

Q. 12

Which of the following is TRUE about portal vein?

 A

Formed by the superior mesenteric vein

 B

Formed by the splenic vein

 C

Situated deep to the hepatic artery and cystic duct

 D

All of the above

Ans. D

Explanation:

Portal vein collects blood from the foregut, midgut, and hindgut. The portal vein is located deep to the hepatic artery and cystic duct and is formed by the union of the superior mesenteric vein and splenic vein, deep to the neck of the pancreas. Blood from portal vein transported to the hepatic sinusoids of the liver for filtration and detoxification. The hepatic sinusoids empty into the common central vein, which empties into the hepatic veins and ultimately drains into the inferior vena cava.

Q. 13

Portal vein is formed by union of which of the following veins?

 A

Superior mesenteric vein & Splenic vein

 B

Superior mesenteric vein & inferior mesenteric vein

 C

Inferior mesenteric vein & Splenic vein

 D

inferior mesenteric vein & Hepatic vein

Q. 13

Portal vein is formed by union of which of the following veins?

 A

Superior mesenteric vein & Splenic vein

 B

Superior mesenteric vein & inferior mesenteric vein

 C

Inferior mesenteric vein & Splenic vein

 D

inferior mesenteric vein & Hepatic vein

Ans. A

Explanation:

Portal vein is formed by the union of Superior mesenteric vein (SMV) and splenic vein posterior to the neck of pancreas. The inferior mesenteric vein drains into the splenic vein. 
  • The hepatic portal vein pass posterior to the first part of duodenum, in the free edge of lesser omentum.
  • At the porta hepatis, it divides into right and left branches supplying the right and left lobes of the liver.
  • Within the sinusoids of the liver, hepatic portal blood and oxygenated blood from the hepatic artery mix together and come into contact with the hepatocytes, where metabolites such as products of digestion are exchanged.
  • Blood from the sinusoids empties into hepatic veins draining the liver and in turn drain into IVC, and blood is returned to heart.

 


Q. 14

The normal portal venous pressure is:

 A

4-6 mm Hg

 B

5-10 mm Hg

 C

26-30 mm Hg

 D

12-16 mm saline

Q. 14

The normal portal venous pressure is:

 A

4-6 mm Hg

 B

5-10 mm Hg

 C

26-30 mm Hg

 D

12-16 mm saline

Ans. B

Explanation:

Portal venous pressure is the blood pressure in the hepatic portal vein, and is normally between 5-10 mmHg.At this pressure very little blood is shunted from the portal venous system into the systemic circulation.
 
Note:
Direct portal venous pressure that is >5 mmHg greater than the inferior vena cava (IVC) pressure, a splenic pressure of >15 mmHg, or a portal venous pressure measured at surgery of >20 mmHg is abnormal and indicates portal hypertension.A portal pressure of >12 mmHg is necessary for varices to form and subsequently bleed.
 
Ref : Geller D.A., Goss J.A., Tsung A. (2010). Chapter 31. Liver. In F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Schwartz’s Principles of Surgery, 9e.

Q. 15

The normal portal venous pressure under normal physiological conditions is:

 A

4-6 mmHg

 B

5-10 mmHg

 C

26-30 mm Hg

 D

12-16 mm saline

Q. 15

The normal portal venous pressure under normal physiological conditions is:

 A

4-6 mmHg

 B

5-10 mmHg

 C

26-30 mm Hg

 D

12-16 mm saline

Ans. B

Explanation:

The portal venous system contributes approximately 75% of the blood and 72% of the oxygen supplied to the liver. In the average adult 1000 to 1500 mL/min of portal venous blood is supplied to the liver. The normal portal venous pressure is 5 to 10 mmHg, and at this pressure very little blood is shunted from the portal venous system into the systemic circulation. As portal venous pressure increases, however, the communications with the systemic circulation dilate, and a large amount of blood may be shunted around the liver and into the systemic circulation.
 
Ref: Tsung A. (2010). Chapter 31. Liver. In T.R. Billiar, D.L. Dunn (Eds),Schwartz’s Principles of Surgery, 9e.

 


Q. 16

In portal venous system, valves are present at

 A

The junction of superior mesentric artery with the splenic artery

 B

Within the portal vein only

 C

In the intrahepatic portion of portal vein

 D

The whole system is valveless

Q. 16

In portal venous system, valves are present at

 A

The junction of superior mesentric artery with the splenic artery

 B

Within the portal vein only

 C

In the intrahepatic portion of portal vein

 D

The whole system is valveless

Ans. D

Explanation:

D i.e. The whole system is valveless

Like vena Cava, the portal vein and its tributaries are without valves. The normal pressure in portal vein is 3-5 mmHg and the increase in venous pressure is distributed throughout the splanchenic circulation.


Q. 17

Portal circulation is seen in which of the following endocrine gland :

 A

Pineal gland

 B

Hypophysis cerebri

 C

Pancreas

 D

Ovary

Q. 17

Portal circulation is seen in which of the following endocrine gland :

 A

Pineal gland

 B

Hypophysis cerebri

 C

Pancreas

 D

Ovary

Ans. B

Explanation:

B i.e. Hypophysis cerebri


Q. 18

True about valves in portal venous system:

 A

Present at the junction of superior mesenteric artery with the splenic artery

 B

Within the portal vein only

 C

The whole system is valveless

 D

In the intrahepatic portion of portal vein.

Q. 18

True about valves in portal venous system:

 A

Present at the junction of superior mesenteric artery with the splenic artery

 B

Within the portal vein only

 C

The whole system is valveless

 D

In the intrahepatic portion of portal vein.

Ans. C

Explanation:

C i.e. The whole system is valveless


Q. 19

Portal vein is related to all except :

 A

Pancreas

 B

Gall bladder

 C

Inf. vena cava

 D

CBD

Q. 19

Portal vein is related to all except :

 A

Pancreas

 B

Gall bladder

 C

Inf. vena cava

 D

CBD

Ans. B

Explanation:

B. i.e. Gall Bladder


Q. 20

Left gastric vein drains into:

 A

Inferior vena cava

 B

Portal vein

 C

Directly into splenic vein

 D

Splenic vein through short gastric vein

Q. 20

Left gastric vein drains into:

 A

Inferior vena cava

 B

Portal vein

 C

Directly into splenic vein

 D

Splenic vein through short gastric vein

Ans. B

Explanation:

B i.e. Portal vein

-Left and right gastric veins drain directly into the portal veinQ.

Portal vein is formed by union of superior mesenteric & splenic veins behind the neck of pancreas at the level of L2 vertebrae and runs

upwards with bile duct & hepatic artery (related anteriorly)(2 and inferior i’ena cava (related posteriorly)


Q. 21

All anesthetic agent decrease portal vein flow. Portal flow is maximally reduced by:

 A

Ether

 B

Halothane

 C

Isoflurane

 D

Enflurane

Q. 21

All anesthetic agent decrease portal vein flow. Portal flow is maximally reduced by:

 A

Ether

 B

Halothane

 C

Isoflurane

 D

Enflurane

Ans. B

Explanation:

B i.e. Halothane

All volatile anesthetic agents reduce portal hepatic blood flow. This decrease is greatest with halothane and least with isofluraneQ.


Q. 22

Normal portal vein pressure is –

 A

< 3 mm Hg

 B

3-5 mm Hg

 C

5-10 mm Hg

 D

10 to 1 2mm of Hg

Q. 22

Normal portal vein pressure is –

 A

< 3 mm Hg

 B

3-5 mm Hg

 C

5-10 mm Hg

 D

10 to 1 2mm of Hg

Ans. C

Explanation:

Ans. is ‘c’ i.e., 5-10 mm Hg 


Q. 23

Normal portal venous pressure is:

 A

3-5 cm saline

 B

5-10 cm saline

 C

10-15 cm saline

 D

15-20 cm saline

Q. 23

Normal portal venous pressure is:

 A

3-5 cm saline

 B

5-10 cm saline

 C

10-15 cm saline

 D

15-20 cm saline

Ans. C

Explanation:

Answer is C (10-15 cm Saline)

Normal pressure in portal vein is low ’10 – 15 cm saline’ – Harrison 14th/ 1710.

Normal pressure in portal vein is low ‘5 -10 mm Hg’ – Harrison 16th/e 1863-


Q. 24

Veins draining into portal vein are all except:

 A

Renal vein

 B

Splenic vein

 C

Left gastric vein

 D

Superior mesenteric vein

Q. 24

Veins draining into portal vein are all except:

 A

Renal vein

 B

Splenic vein

 C

Left gastric vein

 D

Superior mesenteric vein

Ans. A

Explanation:

The portal vein drains blood from the abdominal part of the gastrointestinal tract from the lower third of the esophagus to halfway down the anal canal; it also drains blood from the spleen, pancreas, and gallbladder.

The tributaries of the portal vein are the splenic vein, superior mesenteric vein, left gastric vein, right gastric vein, superior pancreaticoduodenal, paraumbilical and cystic veins.

The portal vein enters the liver and breaks up into sinusoids, from which blood passes into the hepatic veins that join the inferior vena cava. The portal vein is about 2 in. (5 cm) long and is formed behind the neck of the pancreas by the union of the superior mesenteric and splenic veins.


Q. 25

Portal hypertension is said to be present if portal venous pressure is more than: 

March 2010

 A

3-5 mm Hg

 B

5-8 mm Hg

 C

10-12 mm Hg

 D

15-20 mm Hg

Q. 25

Portal hypertension is said to be present if portal venous pressure is more than: 

March 2010

 A

3-5 mm Hg

 B

5-8 mm Hg

 C

10-12 mm Hg

 D

15-20 mm Hg

Ans. C

Explanation:

Ans. C: 10-12 mm Hg

Normal portal pressure is generally defined between 5 and 10 mm Hg.

Portal hypertension results when the portal pressure rises to 12 mm Hg or greater and complications can arise, such as varices and ascites.

Many conditions are associated with portal hypertension, of which cirrhosis is the most common cause


Q. 26

Portal vein is formed ‑

 A

Behind the spleen

 B

Behind the tail of pancreas

 C

Behind the neck of pancreas

 D

Behind the second part of duodenum

Q. 26

Portal vein is formed ‑

 A

Behind the spleen

 B

Behind the tail of pancreas

 C

Behind the neck of pancreas

 D

Behind the second part of duodenum

Ans. C

Explanation:

The portal vein is about 8 cm long.

It is formed by union of superior mesenteric vein and splenic vein behind the neck of pancreas at the level of L2 vertebrae in front of inferior vena cava (IVC).


Q. 27

Posterior relation of portal vein ‑

 A

Pancreas

 B

Gall bladder

 C

Inf. vena cava

 D

CBD

Q. 27

Posterior relation of portal vein ‑

 A

Pancreas

 B

Gall bladder

 C

Inf. vena cava

 D

CBD

Ans. B

Explanation:

Ans. is ‘b’ i.e., Gall bladder

Important relations about portal vein

Infraduodenal part

i) Anterior :- Neck of pancreas

ii) Posterior :- IVC

Retroduodenal part

i) Anterior :- Istpart of duodenum, bile duct, gastroduodenal artery

ii) Posterior :- IVC

Supraduodenal part

i) Anterior :- Hepatic artery, bile duct

ii) Posterior :- IVC, separated by epiploic formen


Q. 28

Which of the following does not form portal triad in liver

 A

Hepatic artery

 B

Hepatic vein

 C

Bile duct

 D

Portal vein

Q. 28

Which of the following does not form portal triad in liver

 A

Hepatic artery

 B

Hepatic vein

 C

Bile duct

 D

Portal vein

Ans. B

Explanation:

Ans. is ‘b’ i.e., Hepatic vein

Histology of the Liver

  • Liver is covered by Glisson’s capsule.
  • Liver is divided into hexagonal lobules oriented around the terminal tributaries of the hepatic vein (Terminal hepatic veins), i.e. Terminal hepatic vein is in the centre of the lobule and area around the hepatic vein is called centrilobular zone.
  • At periphery of lobule, lies the portal tract containing hepatic artery, bile duct and portal vein. Area around portal tract is called periportal zone.
  • These three structures (portal vein, hapatic artery and bile duct) form portal triad.
  • Area between periportal zone and centrilobular zone is called midzonal area.
  • All around the central vein are the major parenchymal cells, i.e. hepatocytes.
  • Lobule contains sinusoid (sinusoidal capillaries) which have fenestrated endothelium covering the subendothelial space of Disse. This space contains stellate cell processes and hepatocellular microvilli.
  • Other important cells of liver are Kupffer cells, which belong to monocytic-macrophage sytem and function as phagocytic cells.

Q. 29

Posterior relation of portal vein –

 A

I’ part of duodenum 

 B

Hepatic artery

 C

Bile duct

 D

IVC

Q. 29

Posterior relation of portal vein –

 A

I’ part of duodenum 

 B

Hepatic artery

 C

Bile duct

 D

IVC

Ans. D

Explanation:

Ans. is ‘d’ i.e., IVC 

  • The portal vein is about 8 cm long. It is formed by the union of the superior mesenteric veins and the splenic vein behind the neck of the pancreas at the level of the second lumbar vertebra. The inferior mesenteric vein drains into the inferior mesenteric vein.

Important facts about portal vein

  • 8 cm long
  • The blood flow is slow
  • Stream line flow :- Blood in superior mesentric vein drains, into right lobe of liver. Blood in splenic and inferior mesentric vein drains into left lobe.
  • Relations
  • Infraduodenal part
  1. Anterior :- Neck of pancreas
  2. Posterior :- IVC
  • Retroduodenal part
  1. Anterior :- Ppart of duodenum, bile duct, gastroduodenal artery
  2. Posterior :- IVC
  • Supraduodenal part
  1. Anterior :- Hepatic artery, bile duct.
  2. Posterior :- IVC, separated by epiploic formen
  • Development of Portal vein :
  1. Infra-duodenal part – part of left vitelline vein distal to the dorsal ansatomosis
  2. Retro-duodenal part – dorsal anastomosis between two vitelline veins
  3. Supra-duodenal part – cranial part of right vitelline vein
  • The portal vein receives the following veins :
  1. Splenic vein
  2. Superior mesenteric vein
  3. Left gastric
  4. Right gastric
  5. Superior pancreatico-duodenal
  • Cystic
  • Paraumbilical veins

Q. 30

Portal vein supplies ‑

 A

Spleen

 B

Liver

 C

Pancreas

 D

Colon

Q. 30

Portal vein supplies ‑

 A

Spleen

 B

Liver

 C

Pancreas

 D

Colon

Ans. B

Explanation:

Ans. is ‘b’ i.e., Liver 

  • Portal vein is a vein, still it supply blood to liver (usually a vein drains blood from an organ or tissue).

The liver has dual blood supply :-

  • 20% of blood supply is through the hepatic artery.
  • 80% of blood supply is through the portal vein.


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