Platelets

Matea Mrčelić, 2nd yearUniversity of Zagreb, School of Medicine2013/2014Mentor: A. Žmegač Horvat

Definition

Small colorless anucleate disk-like body of mammalian blood that assists in blood clotting

Process of differentiation helped and accelerated by thrombopoietin

Each megakaryocyte produces 5,000 – 10,000 platelets

Last step of thrombopoiesis - in bone marrow or in circulation

Lifespan: 10 days, old platelets destroyed in spleen

Function

Platelet count

•Included in complete blood count•Normal range: 150,000 – 300,000 per

microliter•Can be combined with platelet function

test•Useful test for patients receiving

anticoagulant therapy

Thrombocytopenia

•Decrease of platelet count - below 50,000 per microliter

•  Symptoms: easy bruising, frequent bleeding from the gums, nose, or GI tract, thrombocytopenic purpura

•Cause: inherited, medications, chemotherapy, alcoholism

•Treatment: splenectomy or blood transfusion

Easy bruising

Thrombocytopenic purpura

Thrombocytosis

•Having more than 450,000 platelets•Primary and secondary – difference in

causes•Symptoms: spontaneous blood clots in the

arms and legs, which if untreated can lead to heart attack and stroke

•Treatment for primary thrombocytosis: plateletpheresis

References

•Guyton and Hall Textbook of Medical Physiology, 11th Edition

•http://www.platelet-research.org/1/function_hemo.htm#

•http://www.hopkinsmedicine.org/heart_vascular_institute/clinical_services/centers_excellence/womens_cardiovascular_health_center/patient_information/health_topics/platelets.html