Question

The migration of leukocytes out of blood vessels, a process known as extravasation, is thought to occur in steps. In one step, the leukocyte extravasates, or crosses, the endothelial wall. This involves what immunoglobulin-related molecule?

PECAM-1
Mac-1
LFA-1
VLA-4
L-selectin

Answer 1

PECAM-1 is the immunoglobulin-related molecule involved in the process of diapedesis, where leukocytes move from blood vessels into tissues to engage in immune defense mechanisms.The correct option is A.

Step-by-step explanation:

The molecule involved in the extravasation, or crossing, of the endothelial wall by leukocytes, is known as PECAM-1 (Platelet Endothelial Cell Adhesion Molecule-1).

This molecule is immunoglobulin-related and plays a significant role in the process of diapedesis, also known as emigration. During diapedesis, leukocytes squeeze through adjacent cells in a blood vessel wall to enter tissues, particularly areas of infection or inflammation.

This molecular interaction allows the white blood cells to transition from the bloodstream to the tissue where they carry out their defensive functions, such as phagocytosis and destruction of pathogens.The correct option is A.