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血液由骨髓产生的各种细胞组成,这些细胞包括可斜样的红细胞、抗感染的白细胞、止血的血小板。 当红细胞或血红细胞的数量很低时,就会发生贫血。白细胞是免疫系统的重要组成部分,可抵抗感染。当血管损伤时,血液会凝固,以防止出血。 血小板以及血液的其他一些成分参与凝血过程,这些成分凸显出血液中的微妙平衡。

让我们看一下血液的成分。红细胞、白细胞和血小板共同构成血液,含有血浆纤维蛋白源。 血液凝固需要我们的血液。 当小动脉被切断时,可在几分钟内停止一小接口出血,其组织中的胶原纤维暴露, 这标志着凝血过程开始。因为血小板开始粘附在切割边缘, 他们释放出化学物质。为了吸引更多的血小板,最终形成血小板栓 外部出血,阻止血小板附着在纤维蛋白源上。固定的纤维蛋白源吸引凝血因子。 凝血因子将纤维蛋白源转化为纤维蛋白。血栓激酶的聚合物是一种酶复合物,这是必须的。对于这个反应,这个复合物是由一系列连接的酶形成的 麦克反应集连过程涉及血浆中存在的许多因素。在形成纤维蛋白分子后,聚力处于非活性状态, 距离开始被纤维蛋白网吸引。随后这些分子破坏纤维蛋白网, 纤维蛋白溶解,降解产物被巨石细胞 和硫酸性离细胞吞噬, 并且恢复正常的血流。

at any given moment trillions of cells are traveling through your blood vessels sometimes circling the body in just one minute each of these cells has its origins deep in your bones bones might seem rock solid, but they're actually quite porous inside large and small blood vessels enter through these holes and inside most of the large bones of your skeleton is a hollow core filled with soft bone marrow marrow contains fat and other supportive tissue, but its most essential elements are blood stem cells these stem cells are constantly dividing they can differentiate into red blood cells, white blood cells and platelets and send hundreds of billions of new blood cells into circulation every day these new cells enter the bloodstream through holes in small capillaries in the marrow through the capillaries they reach larger blood vessels and exit the bone if there's a problem with your blood there's a good chance it can be traced back to the bone marrow blood cancers often begin with genetic mutations in the stem cells the stem cells themselves are not cancerous, but these mutations can interfere with the process of differentiation and result in malignant blood cells so for patients with advanced blood cancers like leukemia and limphoma the best chance for a cure is often an allergeneic bone marrow transplant which replaces the patient's bone marrow with the donuts here's how it works first blood stem cells are extracted from the donor most commonly blood stem cells are filtered out of the donor's bloodstream by circulating the blood through a machine that separates it into different components in other cases the marrow is extracted directly from a bone in the hip, the iliac crest with the needle meanwhile the recipient prepares for the transplant high doses of chemotherapy or radiation kill the patient's existing marrow destroying both malignant cells and blood stem cells this also weakens the immune system making it less likely to attack the transplanted cells then the donocels were infused into the patient's body through a central line they initially circulate in the recipient's peripheral bloodstream, but molecules on the stem cells called chemo kinds act as homing devices and quickly traffic them back to the marrow over the course of a few weeks they begin to multiply and start producing new healthy blood cells just a small population of blood stem cells can regenerate a whole body's worth of healthy marrow a bone marrow transplant can also lead to something called graft versus tumor activity when new immune cells generated by the donated marrow can wipe out cancer cells the recipient's original immune system couldn't this phenomenon can help eradicate stubborn blood cancers but bone marrow transparents also come with risks including graph versus host disease it happens when the immune system generated by the donor cells attacks the patient's organs this life threatening condition occurs in about thirty to fifty percent of patients who receive donor cells anyone other than an identical twin particularly when the stem tiles are collected from the blood as opposed to the bone marrow patients may take immuno suppressant medications or certain immune cells may be removed from the donated sample in order to reduce the risk of graph vs host disease, but even if a patient avoids graph vs host disease their immune system may reject the donor cells so it's crucial to find the best match possible in the first place key regions of the genetic code determine how the immune system identifies foreign cells if these regions are similar in the donor and the recipient the recipient's immune system is more likely to accept the donor cells because these genes are inherited the best matches are often siblings, but many patients who need a bone marrow transplant don't have a matched family member those patients turn to donor registries of volunteers willing to offer their bone marrow all it takes to be on the registry is a cheek swab to test for a genetic match and in many cases the donation itself isn't much more complicated than giving blood it's a way to save someone's life with a resource that's completely renewable if you'd like to join a bone marrow registry you can visit b the match org to get started or to find a list of affiliated registries around the world。

造血干细胞看起来很懒,其实呢,一点也不勤奋啊,我们画了一个造血干细胞,为什么说他懒呢?呃,接下来我们就讲到了,首先呢,他这个分裂的时候啊,是进行一个不对称性的有色分裂, 哎,上边呢还是一个造血干细胞,下边的话呢,就成了一个方块了,这个呢是早期组细胞,这个早期组细胞呢,他进行的是对称性的有磁分裂,哎,一个变两个,两个变四个。 他进行的是对称性的有磁分裂,会大量扩张,然后再往下走,哎,越来越多,越来越多,就成了两个系,一个呢是随系,被称为随系共同主细胞,这边呢是林系共同主细胞。 然后我们发现啊,下边这个主要干活的呢,是这个主细胞来干活,他这边的话呢,能不动,哎,他即使分裂的话呢,一个还是一个,分裂完之后还是一个,所以说呢,这个造血干细胞的一个数量是不变的, 因为呢,他,哎,人家只要制造出来这个早期主细胞就可以了。然后呢,哎,他去增值,他去这个扩增,跟他没什么关系。所以说呢,这个造血干细胞 绝大多数的造血干细胞呢,是处于一个静止状态,哎,他不分裂,主要是干活,他干活。然后这边这个灵系共同组细胞呢,他会,哎往下来治分化,分化,分化出来之后的话呢, a b 淋巴细胞、 t 淋巴细胞,还有 n k 细胞, n k 细胞是一个自然杀伤细胞,然后这边这个随细共生组细胞的话呢,也会往下继续分化啊,分化完之后,哎,第一个 红系主细胞,聚合系主细胞,单合系主细胞,然后是立系,好,然后这个红系这边,哎,下来的话呢就是 rbc 红细胞聚合,这边下来的话呢就是 plt 好学小本, 然后这个单盒这边呢就是单盒巨石细胞,然后这个利器的话呢就是,哎,是酸性,是碱性和中性。粒细胞, 好,这个三级细胞,一个红细胞,一个血小板,还有白细胞,好,这个这些啊,全都是白细胞,好,这个就是我们的一个造血过程。 大家如果看到这里的话就帮忙点个关注吧,后边呢我们会分享更多有用的内容,祝大家身体健康。

