The regulated exocytosis of secretory granules containing preformed mediators such as histamine and serotonin by a platelet.

The chemical reactions and pathways involving ATP, adenosine triphosphate, a universally important coenzyme and enzyme regulator.

The chemical reactions and pathways involving ATP, adenosine triphosphate, a universally important coenzyme and enzyme regulator.

A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

The volume enclosed by the membrane of the platelet alpha granule.

A vesicle that is released into the extracellular region by fusion of the limiting endosomal membrane of a multivesicular body with the plasma membrane. Extracellular exosomes, also simply called exosomes, have a diameter of about 40-100 nm.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.