Question

Which of the following step is not involved in extravasation of both neutrophils and monocytes?

• A. Activation
• B. Arrest
• C. Adhesion
• D. Replication

Hint:

Extravasation includes rolling, activation, adhesion, arrest, and transmigration. Replication is not a step of extravasation.

Answer 1

The Correct Option is D

Concept:
Extravasation is the process by which leukocytes move out of blood vessels into tissues during inflammation.

Step 1: Understand leukocyte extravasation.
The important steps include rolling, activation, adhesion, arrest, and transmigration through the vessel wall.

Step 2: Check activation.
Activation is involved because chemokines activate leukocytes and increase integrin affinity. \[ A \text{ is involved} \]

Step 3: Check arrest and adhesion.
Leukocytes adhere strongly to endothelial cells and arrest before moving through the vessel wall. \[ B \text{ and } C \text{ are involved} \]

Step 4: Check replication.
Replication means multiplication of cells or genetic material. It is not a step in extravasation. \[ D \text{ is not involved} \] \[ \therefore \text{Correct Answer is (D)} \]