Introduction to Hematology

Platelets are fragments of a much larger cell, the megakaryocyte, that stays in the bone marrow after it differentiates and matures from the stem cell.


The platelets leave the bone marrow and circulate throughout the body. When stimulated by substances from damaged tissue, the platelets release substances necessary to help blood clot. This helps initiate the clotting sequence and protect the integrity of the vasculature.

Section Two: What is Blood?
What is Blood?
How Blood Cells are Made
Red Blood Cells
White Blood Cells