Module 11: Figure platelet structure
Structure of non-adhesive and adhesive blood platelets.
The anucleate circulating platelet is a non-adhesive biconvex disc whose shape is maintained by a ring of microtubules. Aggregating agents induce a dramatic structural change as the disc transform into an adhesive sphere that aggregate with each other to form a thrombus. The microtubule ring breaks down and the peripheral actin microfilaments are remodelled to form long filaments located within the numerous pseudopodia. The α-granules fuse with the plasma membrane to release their contents as part of the activation process that forms a thrombus (Module 11: Figure thrombus formation)