Platelets Matea Mreli 2 nd year University of

Platelets Matea Mrčelić, 2 nd year University of Zagreb, School of Medicine 2013/2014 Mentor: 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 Hemostasis Secretory function Providing platelet phospholipid Producing inflammatory and growth factors Carrying coagulation factors and clot retraction Thromboxane Platelet plug Anti-heparin

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, 11 th Edition • http: //www. plateletresearch. org/1/function_hemo. htm# • http: //www. hopkinsmedicine. org/heart_vascula r_institute/clinical_services/centers_excellence /womens_cardiovascular_health_center/patien t_information/health_topics/platelets. html