This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Platelet biology

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

The primary role of the platelet is the formation of the initial platelet plug during the first phase of haemostasis. Later the platelets provide clotting factors and an extensive phospholipid surface for the generation of fibrin.

The platelet is produced by cytoplasmic budding of the bone marrow megakaryocyte. The megakaryocyte is derived from a haemopoietic stem cell. The production of platelets is stimulated by the cytokine thrombopoietin.

Young platelets are sequestered in the spleen for 36 hours before being released into the circulation. The life span of a platelet is 7-10 days and the normal count is 150-450 x10^9 / litre.

The initial haemostatic event is the adherence of platelets to exposed collagen at sites of endotheliam damage. Von Willebrand's factor is important in platelet adherence. The platelet becomes activated. Activated platelets are able to aggregate using receptors for agents such fibrinogen. Aggregation is stimulated by the release of the contents of two classes of platelet granules:

  • alpha granules, containing:
    • fibrinogen
    • von Willebrand's factor
    • platelet derived growth factor

  • dense granules, containing:
    • nucleotides
    • calcium
    • serotonin

Related pages

Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.