2019.3.5 L261 Are All Our Organs Vital?
Medicine has not always shown a lot of respect for the human body. Just think about the ghoulish disregard early surgeons had for our corporeal integrity. They poked holes in the skull and copiously drained blood with leeches or lancets—a practice that remained a medical mainstay through the late 19th century. Even today many of the most popular surgeries involve the wholesale removal of body parts—the appendix, gallbladder, tonsils, uterus (usually after the childbearing years)—with an assurance that patients will do just fine without them. There are many valid reasons for these “ectomies,” but what has become increasingly less defensible is the idea that losing these organs is of little or no consequence.
Take the appendix. Or rather leave it be, if possible. Many of us learned in school that this tiny, fingerlike projection off the colon is a useless, vestigial remnant of our evolution, much like the puny leg bones found in some snakes. But that idea has been debunked, says evolutionary biologist Heather Smith, director of Anatomical Laboratories at Midwestern University in Arizona. A 2017 study led by Smith reviewed data on 533 species of mammals and found that the appendix appears across multiple, unrelated species. “This suggests there's some good reason to have it,” she says.
The reason appears to be immunological and gastrointestinal. In all species that have an appendix, Smith notes, it either contains or is closely associated with lymphoid tissue, which plays a role in supporting the immune system. In humans, the appendix also harbors a layer of helpful gut bacteria—a fact discovered by scientists at Duke University. In a 2007 paper, they proposed that it serves as a “safe house” to preserve these microbes, so that when the gut microbiome is hit hard by illness, we can replenish it with good guys holed up in the appendix. Some evidence for this idea surfaced in 2011, when a study showed that people without an appendix are two and half times more likely to suffer a recurrence of infection with Clostridium difficile, a dangerous strain of gut bacteria that thrives in the absence of friendlier types.
The appendix may have more far-flung roles in the body—including some that can go awry. A study published last October found that misfolded alpha-synuclein—an abnormal protein found in the brain of Parkinson's disease patients—can accumulate in the appendix. Intriguingly, the study found that people who had the organ removed as young adults appear to have some modest protection against Parkinson's.
New research has also shed light on the value of our tonsils and adenoids. In a study published last July, an international team assessed the long-term impact of removing these structures, or leaving them, in 1.2 million Danish children. Over a follow-up period of 10 to 30 years, the 5 percent or so who had one or both sets of organs extracted before age nine were found to have a twofold to threefold higher rate of upper respiratory diseases and higher rates of allergies and asthma. Notably they suffered more frequently from ear infections and, in the case of adenotonsillectomies, sinus infections—conditions thought to be helped by surgery.
We have known for a long time that the adenoids and tonsils “act as a first line of defense against pathogens that enter through the airways or eating,” says Sean Byars, a senior research fellow at the Melbourne School of Population and Global Health and lead author of the paper. The fact that these tissues are most prominent in children, with the adenoids nearly gone by adulthood, has bolstered the view that they are not essential, but as Byars points out, “maybe there's a reason they are largest in childhood.” Perhaps they play a developmental role, helping to shape the immune system in ways that have lasting consequences.
Byars cautions that his study, large though it is, awaits confirmation by others and that the decision to treat any given child must be made on an individual basis. Still, he says, “Given these are some of the most common surgeries in childhood, our results suggest a conservative approach would be wise.”
It is worth noting that tonsillectomy rates have declined in the U.S., especially since the heyday in the mid-20th century. Surgeons are also doing fewer hysterectomies, reflecting a growing view that the uterus does not outlive its usefulness once childbearing is done and that there are less drastic ways to address common issues such as fibroid tumors.
So are any human body parts truly useless or vestigial? Perhaps the best case can be made for the wisdom teeth. “Our faces are so flat, compared with other primates, that there's often not room for them,” Smith observes. And given how we butcher and cook our food, “we really don't need them.”
2019.3.5 L261 Are All Our Organs Vital?的更多相关文章
- 【AIOT】智能感知--人
From: https://liudongdong1.github.io/ 1. 人体存在感知 目标:检测环境中的所有人体,标记出每个人体的坐标位置:不限人体数量,适应中低空斜拍.人体轻度遮挡.截断等 ...
- 2019年台积电进军AR芯片,将用于下一代iPhone
近日,有报道表示台积电10nm 芯片可怜的收益率可能会对 2017 年多款高端移动设备的推出产生较大的影响,其中自然包括下一代 iPhone 和 iPad 机型.不过,台积电正式驳斥了这一说法,表明1 ...
- VS经常报错的link error 2019
VS经常报错的link error 2019 原因如下: 可能是找得到头文件,但是相关的dll或者lib找不到,需要在配置里面添加相应的库文件. project=>configuration.. ...
- YTU 2019: 鞍点计算
2019: 鞍点计算 时间限制: 1 Sec 内存限制: 64 MB 提交: 66 解决: 30 题目描述 找出具有m行n列二维数组Array的"鞍点",即该位置上的元素在该行 ...
- Windows Server 2019 预览版介绍
在Windows server 2012.Windows server 2016还未完全普及的情况下,昨天Windows Server团队宣布Windows Server 2019将在2018年的下半 ...
- Telerik控件集-2019.R1.SP1.All
Telerik 专注于微软.Net平台的表示层与内容管理控件,提供高度稳定性和丰富性能的组件产品DevCraft,并可应用在非常严格的环境中.Telerik拥有 Microsoft, HP, Alco ...
- CTF丨2019互联网安全城市巡回赛·西安站,我们来了!
万物互联时代,网信事业发展突飞猛进,互联网悄然渗透到国民生活的每一个角落,伴随而来的网络安全威胁和风险也日渐突出.网络诈骗.钓鱼软件.勒索病毒等安全问题层出不穷,信息泄露等网络安全事件也频繁上演,给用 ...
- AI2(App Inventor 2)离线版服务器(2019.04.28更新)
我们的目标:搭建一个本地多用户的App Inventor 2 服务器 演示: http://ai2.fsyz.net [旧 win] http://ai2n.fsyz.net [新 Ce ...
- Adobe Photoshop CC 2019 for Mac v20.0.4 中文版安装教程
全新Adobe Photoshop CC 2019 mac特别版终于上线了,简称ps cc 2019,Adobe Photoshop CC 2019 for Mac v20.0.4 中文版安装教程分享 ...
随机推荐
- 用 JS 设置图片的最大宽度
//用 JS 设置图片的最大宽度 function setImgsMaxWidth() { $('.answerimg img').each(function () { ...
- 【Java】【8】StringUtils中isNotEmpty和isNotBlank的区别
前言: 1,StringUtils.isNotEmpty(str)和StringUtils.isNotBlank(str)都是用来做非空判断的 2,通常用isNotBlank 3,import org ...
- python 解析与生成xml
xml.etree.ElementTree模块为xml文件的提取和建立提供了简单有效的API.下文中使用ET来代表xml.etree.ElementTree模块. XML是一种内在的分层的数据形式,展 ...
- noip2013转圈游戏
题目描述 n个小伙伴(编号从 0到 n−1)围坐一圈玩游戏.按照顺时针方向给 n个位置编号,从0 到 n−1.最初,第 0号小伙伴在第 0号位置,第 1号小伙伴在第 1 号位置,……,依此类推. 游戏 ...
- loj 10001 种树
*********贪心,把需要的路段终止点排序,然后在每个区间内判断是否已经满足条件,不满足的从区间右端向左端种树. #include<cstdio> #include<algori ...
- select 练习语句
select * from scott.dept; /查看scott.dept表中的全局信息. describe scott.emp: ...
- ubuntu 挂载虚拟机vdi文件
sudo apt-get install nbd-server nbd-client qemu-kvm # rmmod nbd # modprobe nbd max_part=8 # qemu- ...
- ubuntu16.10安装网易云音乐
首先去官网(https://music.163.com/#/download)下载安装包:netease-cloud-music_1.1.0_amd64_ubuntu.deb 下载好以后,执行安装命令 ...
- Win10系列:UWP界面布局基础5
(2)编写后台代码访问资源 下面通过一个例子来演示如何编写后台代码引用资源.新建一个Windows应用商店的空白应用程序项目,将其命名为AccessResourceApplication,打开项目下的 ...
- Win10系列:VC++媒体播放控制1
在MediaElement控件中定义了用于控制视频播放的函数,如Play.Pause和Stop等函数.本小节将在20.6.1小节所新建的项目基础上继续来介绍如何为视频添加播放控制,并在最后一部分给出项 ...