Color enhanced scanning electron micrograph (SEM) of red blood cells found enmeshed in a fibrinous matrix on the luminal surface of an indwelling vascular catheter; Magnified 7766x. In this instance,the indwelling catheter was a tube that was left in place creating a patent portal directly into a blood vessel. The cell in the centre was a white blood cell,also known as a leucocyte. The biconcave cytomorphologic shape of the red blood cell,or erythrocyte,increases its surface area of this hemoglobin-filled cell,thereby,promoting a greater degree of gas exchange,which is its primary function in an in vivo setting. In their adult phase,these cells possess no nucleus. What appears to be irregularly-shaped chunks of debris,are actually fibrin |