Question

Assertion - (A) The hepatic portal vein exhibits a wide lumen and comparatively thinner tunica media.
Reason - (R) Its endothelial lining is arranged in a tessellated pattern to facilitate exchange between blood and hepatocytes.
Choose the correct option from the following.

• A. Both (A) and (R) are true, and (R) is the correct explanation for (A).
• B. Both (A) and (R) are true, but (R) is NOT the correct explanation for (A).
• C. (A) is true; however, statement (R) is false.
• D. (A) is false; however, (R) is true.

Hint:

The portal vein has a wide lumen and thin tunica media, but exchange with liver cells happens in sinusoids, not through its wall.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Veins carry blood at low pressure, so they have a wide lumen and a thin tunica media of smooth muscle.

Step 2: Assertion
The hepatic portal vein is a vein, so it has a wide lumen and a comparatively thin tunica media. The assertion is true.

Step 3: Reason
Exchange between blood and liver cells does not take place through the wall of the portal vein.
The vein branches inside the liver and exchange occurs in the hepatic sinusoids, which have leaky endothelium. The reason is false.

Final Answer:
The assertion is true but the reason is false. \[ \boxed{\text{(C) }\text{(A) is true; however, statement (R) is false.}} \]