Martin Oeggerli Fibrin is a protein created by the body that works with platelets in the blood to clot a wound. As they reach the wound site, they attach themselves to fibers, and create a mesh. Working with the platelets, they make a scab that covers the wound until it heals. Though, with the naked eye you would never guess that the process looks like this.
Bone marrow, colored SEM. This freeze-fracture has revealed the cavity (lumen) of a large venous sinus (pink), which contains mature blood cells (red), and developing white blood cells (blue). On either side of the sinus are the hematopoetic foci of the marrow (green). 3000x
The bacteria appear pink. The macrophage (appearing blue) is stretching out and engulfing (eating) them. Macrophages are a type of white blood cell which acts as a 'Pacman' in our bodies - it eats foreign bodies (like bacteria) and digests them. This is part of your body's front line defense against invaders.
Ruptured venule. Coloured scanning electron micrograph (SEM) showing stacks (rouleaux) of red blood cells exposed inside a torn venule. A venule is a very small blood vessel in the microcirculation that allows deoxygenated blood to return from the capillary beds to the larger blood vessels (veins). Red blood cells are the most abundant cell in the blood. They have no nucleus and are about 7 micrometers across. Magnification: x2300 when printed at 10 centimetres wide.