这是血小板的电镜图。 注意此血小板与巧克力碎片甜饼有惊人的相似之处。巧克力碎片中有透明和致密颗粒，其中包括不同的介质，例如腺苷二磷酸。当血小板被激活时它会释放颗粒以促进血小板凝固并改变其形状使血小板凝固起来阻塞血管。
Here is an actual electron micrograph of a platelet. Note that this platelet bears a striking resemblance to a chocolate chip cookie. The chocolate chips are the alpha and dense granules that contain a variety of mediators such as ADP. When activated, platelets release their granules to promote coagulation, change shape, and become sticky to aggregate and plug small vascular holes.