What is the marrow?

The marrow is the porous fabrics being in some bones. It plays important role as contains the special cages known as stem cells.

Stem cells develop other special cages which carry out important functions. Stem cells in a marrow develop three important types of blood little bodies:
rasny blood little bodies which transfer oxygen on an organism
white blood little bodies which help to struggle with infections
plates which help to stop bleedings.