«Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation. Circulating unactivated platelets are biconvex discoid (lens-shaped) structures,:117–18 2–3 µm in greatest diameter. Activated platelets have cell membrane projections covering their surface. Platelets are found only in mammals, whereas in other animals (e.g. birds, amphibians) thrombocytes circulate as intact mononuclear cell.:3
On a stained blood smear, platelets appear as dark purple spots, about 20% the diameter of red blood cell. The smear is used to examine platelets for size, shape, qualitative number, and clumping. The ratio of platelets to red blood cell in a healthy adult ranges from 1:10 to 1:20. One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: adhesion. Second, they change shape, turn on receptors and secrete chemical messengers: activation. Third, they connect to each other through receptor bridges: aggregation. Formation of this platelet plug (primary hemostasis) is associated with activation of the coagulation cascade with resultant fibrin deposition and linking (secondary hemostasis). These processes may overlap: the spectrum is from a predominantly platelet plug, or "white clot" to a predominantly fibrin, or "red clot" or the more typical mixture. Some would ad the subsequent retraction and platelet inhibition as fourth and fifth steps to the completion of the process and still others a sixth step wound repair. Platelets also participate in both innate and adaptive intravascular immune response.
Low platelet concentration is called thrombocytopenia, and is due to either decreased production or increased destruction. Elevated platelet concentration is called thrombocytosis, and is either congenital, reactive (to cytokines), or due to unregulated production: one of the myeloproliferative neoplasms or certain other myeloid neoplasms. A disorder of platelet function is a thrombocytopathy.
Normal platelets can respond to an abnormality on the vessel wall rather than to hemorrhage, resulting in inappropriate platelet adhesion/activation and thrombosis: the formation of a clot within an intact vessel. This type of thrombosis arises by mechanisms different from those of a normal clot: namely, extending the fibrin of venous thrombosis; extending an unstable or ruptured arterial plaque, causing arterial thrombosis; and microcirculatory thrombosis. An arterial thrombus may partially obstruct blood flow, causing downstream ischemia, or may completely obstruct it, causing downstream tissue death.» (wikipedia)
Do something with Platelets
Lists what BioMindmap can do with its medical objects for demo purposes.
- See 12 Biolinks that connect Platelets with other objects
- Group Biolinks by type — promoters and inhibitors separately
- Summarize how other objects relate to Platelets
- There are 14 Evidences supporting 12 Platelets Biolinks
Guide for Good Sources list of respected domains.
The ValidityScore showsthe quality of evidences, with max 9.9.
- Platelets Mindmap — near connections
- Mindmap with ValidityScore 5.0 — near connections
- Mindmap of Platelets. and Subnodes: .
- Find Path to another object.
- Build Custom Map
- Instream into nodes that connect into Platelets.
- Outstream from nodes that go out from Platelets.
- Promoters of Platelets
- Add biolink i.e. «X increases Platelets». Intuitively easy.
- Power-start: watch the Intro Video and Guide in Help Center
- Users improve Reputation by getting experienced and validated.
- Ask Telegram Bot to get quick Summary on any object.