What does red blood cell look like?

Brief description of human red blood cell (RBC):

"At static state, RBCs adhered to each other side-by-side to form structures known as rouleaux. These rouleaux could expand to become a large network of aggregates throughout the blood. Rouleaux gave mechanical coupling between different fluid regions, so to enhance the resistance to deformation of cellular particles. The more rouleaux were formed, the more viscous the blood would become. The attractive forces between red blood cells to form rouleaux were probably caused by the charged groups on the surface of the cells. Rouleaux formation was also dependent on the presence of certain macromolecules such as fibrinogen and globulins in the blood."

If you don't understand a thing above, its perfectly normal. You are not an engineer by profession. Me too. Just for curiosity sake.

(Picture courtesy of a Masters of Engineering freshman's final thesis)