Why those WBC has a large counting surface as compared to platelets and RBC?

White blood cells (WBCs) have a larger counting surface compared to platelets and red blood cells (RBCs) because they are involved in the immune response and defense against pathogens.

WBCs are responsible for recognizing and eliminating foreign substances, such as bacteria, viruses, and other pathogens, from the body. They do this by engulfing and destroying these invaders through a process called phagocytosis.

To effectively carry out their immune functions, WBCs need to have a larger surface area to interact with and engulf pathogens. This larger surface area allows for more receptors and binding sites on the cell membrane, which enables the WBCs to recognize and attach to the pathogens more efficiently.

In contrast, platelets are small cell fragments involved in blood clotting, and RBCs are responsible for carrying oxygen to tissues. They do not have the same immune functions as WBCs, so they do not require a large counting surface. Platelets and RBCs have specialized shapes and structures that allow them to perform their respective functions efficiently.