This is the red blood cell (erthrocyte). Does this cell actually have a hole in the center?
Why is it thin in the middle?
No, the red blood cell (erythrocyte) does not have a hole in the center. The thinning or concave shape in the middle is a natural characteristic of red blood cells.
The main reason for the concave shape is to increase the cell's surface area, facilitating the efficient exchange of oxygen and carbon dioxide. The thinning in the middle allows the cell to flex and deform as it passes through narrow capillaries and vessels, ensuring its smooth flow and maximizing contact with the surrounding tissues. This shape also increases the cell's flexibility, enabling it to navigate through the circulatory system and reach distant parts of the body.