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《生物学》课本上讲到血小板时,都离不开“没有细胞核、形状不规则……形成凝血块堵塞伤口而止血”的描述。其实,血小板并没有这样的简单,它同人体的许多重要生理功能相关,而且是对付入侵病毒的主要防线。奇特的细胞结构在人的3种血细胞中,红细胞运输氧气带走二氧化碳,白细胞消灭病原体,功能显赫,好像就血小板的功能次要。但科学研究说明,血小板并不简单,只是以前人们对它的研究不够。首先,血小板的形状不是不规则,而是很特殊。在血液中,血小板是扁球形的,但当附着在血管壁上时,它们就铺张开来,从扁圆形变成星状,伸出的一条条射线,一下子使表面积增大到5～10倍! 它虽然同红细胞一样没有细胞核,但结构十分复杂。在血小板的中央,有许多像发芽的树枝状突起,细胞质中有大量星星点点的黑色颗粒。这些都是血小板的细胞器,它们是在血小板生成时,由骨髓中的母细胞分配给予的。按生物学规则,一个完整的细胞是不能没有细胞核的,因为核是细胞的指挥中心,里边有遗传物质。没有核细胞就会死亡,但血小板却活着并工作着,这全靠从母细胞带入的指
When “biology” textbooks talk about platelets, they all can’t do without the description of “no nucleus, irregular shape...form clot blocking the wound and stop bleeding”. In fact, platelets do not have such simplicity. It is related to many important physiological functions of the human body and is the main line of defense against invading viruses. The peculiar cellular structure Among the three types of blood cells in humans, red blood cells transport oxygen to transport carbon dioxide, and leukocytes destroy pathogens. They have prominent functions and seem to have secondary functions of platelets. However, scientific research shows that platelets are not simple, but people have not studied it enough before. First of all, the shape of platelets is not irregular but very special. In the blood, the platelets are oblate, but when attached to the walls of the blood vessels, they spread out, transforming from oblate to star-shaped, protruding rays, all of which increase the surface area to 5 to 10 Times! Although it has no nuclei like red blood cells, its structure is very complicated. In the center of platelets, there are many sprouting dendrites, and there are a large number of scattered black particles in the cytoplasm. These are the organelles of platelets, which are distributed by the mother cells in the bone marrow when platelets are produced. According to biological rules, a complete cell cannot have no nucleus, because the nucleus is the cell’s command center and there are genetic material inside. No nucleated cells die, but platelets live and work, thanks to the fingers brought in from mother cells.