TED演讲:生病时感到难受的惊人原因(2)

 　　That's where those unpleasant symptoms come in, starting with the surging temperature, aches and pains, and sleepiness. 那就是引起不适症状之所在开始时，体温剧升、肌肉酸痛及昏昏欲睡。

　　So why do we experience this? 为什么我们有这感受呢？

　　When the immune system is under serious attack, it secretes¹ more cytokines, which trigger two responses. 当免疫系统遭受严重攻击，它会分泌更多细胞因子以激发两种反应。

　　First, the vagus nerve, which runs through the body into the brain,  第一，迷走神经是从全身汇聚至脑部迅速地传递讯息到脑干，

　　quickly transmits the information to the brain stem, passing near an important area of pain processing. 它会通过处理疼痛的重要区域附近。

　　Second, cytokines travel through the body to the hypothalamus,  第二，细胞因子从全身运行到下视丘

　　the part of the brain responsible for controlling temperature, thirst, hunger, and sleep, among other things. 这部分的脑负责控制体温、口渴、饥饿，及睡眠等等。

　　When it receives this message, the hypothalamus produces another molecule² called prostaglandin E2, which gears it up for war. 当下视丘接收到讯息，它会制造另一种分子，称为“前列腺素E2”，让它进入备战。

　　The hypothalamus sends signals that instruct your muscles to contract and causes a rise in body temperature. 下视丘发出信号指示肌肉收缩，因而导致体温上升。

　　It also makes you sleepy, and you lose your appetite and thirst. 它也使你昏昏欲睡，以及丧失食欲和口渴感。

　　But what's the point of all of these unpleasant symptoms? 但所有这些不适症状有何意义呢？

　　Well, we're not yet sure, but some theorize that they aid in recovery. 这个我们还不确定，但有些推测它们会帮助复原。

　　The rise in temperature can slow bacteria and help your immune system destroy pathogens. 体温升高可阻碍细菌以及协助免疫系统杀死病原体。

　　Sleep lets your body channel more energy towards fighting infection. 睡眠让身体集中更多精力以对抗感染。

　　When you stop eating, your liver can take up much of the iron in your blood,  当停止进食，肝脏就能在血中吸收很多铁，

　　and since iron is essential for bacterial³ survival, that effectively starves them. 因为铁是细菌生存所必需的，如此可有效地使之匮乏。

　　Your reduced thirst makes you mildly dehydrated, diminishing transmission through sneezes, coughs, vomit⁴, or diarrhea. 口渴感降低使身体呈现轻度脱水，减少经由打喷嚏、咳嗽、呕吐或腹泻的传播。

1 secretes   

v.（尤指动物或植物器官）分泌( secrete的第三人称单数 )；隐匿，隐藏

参考例句：

• The pineal gland secretes melanin during times of relaxation and visualization. 松果体在放松时分泌黑色素是明白无误的。 来自互联网
• For example, the archegonium (female organ) of the moss Funaria secretes sucrose. 例如藓类颈卵器（雌性器官）分泌蔗糖。 来自互联网

2 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

3 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

4 vomit   

v.呕吐，作呕；n.呕吐物，吐出物

参考例句：

• They gave her salty water to make her vomit.他们给她喝盐水好让她吐出来。
• She was stricken by pain and began to vomit.她感到一阵疼痛，开始呕吐起来。