Activate Ailment Anatomical Anatomy Biological Biology Blood Cell Blood Clot Blood Platelet Blood Vessel Blood Vessel Disease Body Bone Bone Marrow Bone Tissue Cardiovascular Cardiovascular System Cardiovascular Disease Cell Cell Structure Cellular Channel Circulatory System Circulatory System Disease Clot Clotting Connective Tissue Connective Tissue Cell Cytology Cytoplasm Cytoplasmic Disease Disorder Endothelial Endothelium Epithelial Epithelium Epithelia Epithelial Tissue Epithelial Type Form Fragment Histologic Histological Histology Human Illness Important Life Science Marrow Medical Medicine Micrograph Micrography Microscopy Myeloid Tissue Normal Cell OCS Open Canalicular System Organ System Part Pavement Platelet Properties Protoplasm Repair Scanning Electron Micrograph SEM Simple Squamous Skeletal System Squamous Epithelium Surface Thrombocyte Tissue Vas Vascular Disease Vessel SEM of activated top and nonactivated bottom platelets on a blood vessel endothelial cell surface mag 3000x at 24 x 36 mm Note the channels of the open canalicular system OCS Platelets are cytoplasmic fragments formed by fragmentation of bone marrow cells and are important in blood clotting and wound repair Activation is required for clotting