The cells of the body for 7 years to replace it again Don’t make excuses for the seven year itch (vi-mide-031

The cells of the body for 7 years to replace it again? Don’t make excuses for the "seven year itch" seven years is a hurdle, may let the couple break, this is known as "the seven year itch". The online forum has many questions: Why did it happen "seven year itch"? This problem, there is a seemingly quite scientific truth replied: "the cells of the body will The new supersedes the old., every three months will be replaced once, as old cells die, new cells are born. Due to the different cell metabolism in different time intervals, to replace all cells, need seven years. That is to say, in the physiology, we every seven years is another person. You are who you are, but you are not you." But is it really the case? We want to determine human cells from the carbon age of 14 speaking. The Swedish Rawlins card card research center Jonas Fries professor of Archaeology from grace inspired carbon concentration of 14 can be used as a marker of cell age. Carbon 14 is a radioactive isotope of carbon, from cosmic rays in the atmosphere of shock, the half-life is 5730 years, the content in the atmosphere is relatively stable. But from the middle of 50s to early 60s, people do a lot of nuclear tests on the ground, the extra radiation makes the atmospheric carbon concentration of 14 increased significantly. In 1963 after a ban on the ground, no such sources can produce large amounts of carbon 14. So with the diffusion and exchange with ocean water, atmospheric carbon content showed a rapid decline index 14. For single cell, from the date of birth, DNA almost no occurrence of material exchange, which contains 14 carbon is at a relatively stable level (natural decay of carbon 14 within a few decades, very little) was equal to the atmospheric carbon concentration of 14. Therefore, the first organism cell DNA 14 carbon content, and the atmospheric carbon concentration curve 14 corresponds to the launch of the cell birth time. The cells of the body for 7 years to replace it again? Don’t make excuses for the "seven year itch" it is carbon 14 mark this tool, Professor Vries Don began to analyze some of the human body cell age. Due to the limited sample, his team can only temporarily focus on parts of the human body cell. Through the analysis, they found that the average age of intestinal cells in the adult is about 10.7 ± 3.6. But some previous studies have shown that due to the harsh environment, intestinal epidermal cells only 5 days of life. When Professor Vries Don removed the ephemeral epidermal cells, the average age of intestinal cells was about 15.9 years old. In addition, they also found that human skeletal muscle the mean age was about 15.1. As Professor de Free Sean neurobiologist, the main purpose of this study is to carry out the study whether neurons of cerebral cortex regeneration problems. This study shows that neurons with age the occipital cortex of the same age, but because of glial cells and update, so the average age measured than age low age. The occipital cortex is considered to be the most prone to cell regeneration in the mammalian cerebral cortex area. This study suggests that the researchers consider the cerebral cortex).

人体细胞7年更换一遍?不要为“七年之痒”找借口 七年是一道坎,可能会让夫妻闹掰,这就是人们所说的“七年之痒”。网上许多论坛都有提问:为什么会发生“七年之痒”?对此问题,有一个看似颇有科学道理的回答:“人体的细胞会新陈代谢,每三个月会替换一次,随着旧细胞的死去,新细胞诞生。由于不同细胞代谢的时间和间隔的不同,将一身细胞全部换掉,需要七年。也就是说,在生理上,我们每七年就是另外一个人。你就是你,但你也不是你了。”这是真的吗?我们要从碳14测定人体细胞的年龄说起。 瑞典卡罗林斯卡研究中心的约拿斯•弗里斯恩教授从考古学中得到了灵感——碳14浓度可以作为细胞年龄的标记。碳14是碳的一种放射性同位素,来自宇宙射线对大气层的冲击,半衰期为5730年,在大气中的含量是比较稳定的。但从上世纪50年代中期到60年代早期,人类在地面上进行了许多次核试验,产生的额外放射线使得大气中碳14浓度显著升高。而在1963年的一纸禁令后,地面上再无这种能够产生大量碳14的来源了。因此随着扩散和与大洋水体的交换,大气中的碳14含量呈快速的指数下降。而对于单个细胞来说,从诞生之日起,DNA就几乎不再发生物质交换,其中所含的碳14也就处于一个相对稳定的水平(碳14的自然衰变在几十年内微乎其微),等于当时的大气碳14浓度。 因此,先测定生物体细胞DNA的碳14含量,再与大气的碳14浓度变化曲线相对应,就能够推出该细胞诞生的时间。 人体细胞7年更换一遍?不要为“七年之痒”找借口 有了碳14标记这件工具,弗里斯恩教授开始着手分析人体内一些细胞的年龄。由于样本有限,他的团队只能暂时专注于部分区域的人体细胞。通过分析,他们发现成年人的肠道细胞平均年龄约为10.7 ± 3.6岁。不过先前的一些研究表明,由于身处环境的恶劣,肠道表皮细胞只有5天的寿命。当弗里斯恩教授去除这些生命短暂的表皮细胞后,肠道细胞的平均年龄约为15.9岁。此外,他们还发现人体的骨骼肌平均年龄约为15.1岁 。 作为神经生物学家的德弗里斯恩教授,开展这项研究的主要目的还是在于研究大脑皮层的神经元细胞是否会再生的问题。这项研究显示,枕叶皮质的神经元细胞年龄与人的年龄相同,但因为神经胶质细胞还有更新,所以测得的平均年龄比人的年龄低几岁。枕叶皮质被认为是哺乳动物大脑皮层中最容易出现细胞再生的区域。因此研究者认为这项研究提示我们,大脑皮层的几乎所有神经元细胞应该在出生后不久就已经存在了,除了在损伤情况下或是在个别区域,不会有新细胞诞生。 人体的细胞种类远不止弗里斯恩教授研究的这几种,拥有较高替换率的细胞也不在少数。除了上文中提到的肠道表皮细胞外,红细胞也平均只有120天可活。寿命稍长一点的肝脏细胞约有300-500天的寿命,而看似终身不变的人体骨架约每10年也会重新更换一次。如果把这些不同种类的细胞综合起来看,整个人体内细胞的平均年龄大约为7-10岁。 由此我们得出以下结论: 一、在现有的知识范围内,除了少数能够更新的嗅球或海马体神经元,其他神经元细胞则几乎要陪伴人的一生,其中就包括了那些作为人类情感基础的神经元细胞。 二、即便男女之间真的出现了“七年之痒”,而不得不用仅限于细胞生物学的知识去解读,那也应将其归咎于这些神经元对人类行为的影响发生了改变,而非斥之于莫须有的神经细胞新陈代谢。 三、男女之间感情出现问题又不单是细胞层面的问题,人所接受的教育、身处的环境、曾经的经历都会产生一定的影响。 关注与质疑:世界首个细胞核移植“三父母”婴儿诞生 (该视频仅供延展)动动手指,随时查询交通违法! 扫一扫下方二维码,关注腾讯大申网! 欢迎关注腾讯大申网微信(微信号:dashenw)相关的主题文章: