Everyone has experienced the pain of a fall.
When the wound was bleeding, I couldn’t help grinning, but at this time, in the blood vessels, a group of lovely “repairers” had already moved to the wound, and tried their best to stick it for you as soon as possible. Put on a “Band-Aid”.
They are cute “platelets”.
Platelets, a member of the blood component, are small, round, soft and cute.
You may not imagine that in a healthy adult, there are 100 million platelets that “patrol” along both sides of the inner wall of blood vessels every day.
They carry a variety of “detectors” to detect conditions, chief among them the platelet membrane glycoprotein Ib (GPIb).
When you are injured and bleed, there is a barrier called endothelial cells in blood vessels. When endothelial cells are damaged, a factor code-named “vWF” will be exposed. At this time, platelets The detector in hand will come into play:
Not only does it detect it, it binds to it, so the platelets stick to the wound!
Platelets are quite team spirit. Although they have no advantage in stature, they are short in stature and have short arms, but in order to protect your safety, they will “weave a net”:
With the help of the integrin αIIbβ3 receptor, it binds to fibrinogen or vWF so that they connect to each other, woven into a Band-Aid that seals the wound from the inside of the blood vessel [1].
In order to restore the integrity of the vessel walls, they begin to signal “seek help”.
1
Organization Mobilizer – P-Selectin
Activated platelets expose P-selectin, which recruits larger white blood cells to seal the wound and clear bacteria.
2
“signal bombs” – such as factor V and negatively charged phospholipids
Release a “signal bomb” – activating thrombin, which can further activate platelets, attract partners, and at the same time, recruit more white blood cells.
When thrombin is activated in a cascade, a fibrin mesh is formed at the wound, which traps other blood cells to form a clot, strengthens the platelet embolus, completely seals the blood vessels at the injured site, and completes hemostasis. [2].
If you always:
Uninjured but inexplicable nosebleed
Gum bleeding is also easy with a soft brush
I feel that even if there is no bump, the body will be blue and purple
Then be careful, it could be thrombocytopenia [3]!
Normal platelet count (150-400) x 19/L, if less than 150 x 109/L is called thrombocytopenia[4].
In daily life, there are various reasons for blood vessel damage:
It may be a cold and a diarrhea, bacteria and viruses enter the bloodstream and destroy the blood vessels;
It may be a collision, the external force squeezes and damages the blood vessel;
It could also just be doing nothing, and the high-speed flow of blood is hitting the blood vessels.
Vascular damage exists at any time. If there are too few “platelets” in the Band-Aid to repair the wound in time, the various bleeding symptoms mentioned above will occur.
Thrombocytopenia is divided into 3 grades: mild to moderate, and the lower the platelet count, the more severe it is.
Mild to moderate thrombocytopenia:
Unexplained nosebleeds, bleeding gums, bruises from minor bumps, and “blue and purple patches” on the skin.
Severe thrombocytopenia:
In addition to the above (mild to moderate thrombocytopenia) symptoms, life-threatening conditions such as hematemesis, blood in the stool, and intracranial hemorrhage may occur even in the absence of underlying diseases.
In particular:
If you often have unexplained nosebleeds, bleeding gums, and skin ecchymosis, accompanied by symptoms such as fever, fatigue, shortness of breath, etc., you should highly suspect leukemia, aplastic anemia, etc. Very difficult blood disease, it is recommended to go to the regular hospital hematology department immediately!
These “little angels” in your body that you can’t see will “save yourself” without hesitation when you are injured, and they will do their best to protect you.
There are always bumps on the road to growth
But there is always someone watching over you
Don’t be afraid, go ahead
Contributing Author: Ruiqi Zhu
Resident Physician, Department of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
References
[1]Tomaiuolo, M., Brass, L. F. & Stalker, T. J. Regulation of Platelet Activation and
Coagulation and Its Role in Vascular Injury and Arterial Thrombosis. Interv Cardiol Clin
6, 1-12, doi:10.1016/j.iccl.2016.08.001 (2017).
[2]Holinstat, M. Normal platelet function. Cancer Metastasis Rev 36, 195-198,
doi:10.1007/s10555-017-9677-x (2017).
[3]Lee, E. J. & Lee, A. I. Thrombocytopenia. Prim Care 43, 543-557,
doi:10.1016/j.pop.2016.07.008 (2016).
[4]Kaushansky, K. et al. “Williams Hematology (9th Ed.)” (2016). Faculty Bookshelf. 72.
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