Nestled in the tissues of your neck is a small unassuming organ that wields enormous power over your body. It's called the thyroid. Like the operations manager in a company, its role is to make sure that the cells in your body are working properly. It does that by using hormones to deliver messages to every single one of them. This high-ranking organ is made up of lobules that each contains smaller cells called follicles, which store the hormones the thyroid sends out into your blood. Two of the most important hormones it produces are thyroxine and triiodothyronine, or T3 and T4. As messengers, the hormone's job is to instruct every cell in the body when to consume oxygen and nutrients. That maintains the body's metabolism, the series of reactions our cells perform to provide us with energy. This hormonal notification from the thyroid gets the heart pumping more efficiently, and makes our cells break down nutrients faster. When you need more energy, the thyroid helps by sending out hormones to increase metabolism. Ultimately, the thyroid allows our cells to use energy, grow and reproduce. The thyroid is controlled by the pituitary gland, a hormonal gland deep in the brain that oversees the thyroid's tasks, making sure it knows when to send out its messengers. The pituitary's role is to sense if hormone levels in the blood are too low or too high, in which case it sends out instructions in the form of the thyroid- stimulating hormone. Even in this tightly controlled system, however, management sometimes slips up. Certain diseases, growths in the thryoid or chemical imbalances in the body can confuse the organ and make it deaf to the pituitary's guiding commands. The first problem this causes is hyperthyroidism, which happens when the organ sends out too many hormones. That means the cells are overloaded with instructions to consume nutrients and oxygen. They become overactive as a result, meaning a person with hyperthyroidism experiences a higher metabolism signaled by a faster heartbeat, constant hunger, and rapid weight loss. They also feel hot, sweaty, anxious, and find it difficult to sleep. The opposite problem is hypothyroidism, which happens when the thyroid sends out too few hormones, meaning the body's cells don't have as many messengers to guide them. In response, cells grow listless and metabolism slows. People with hypothyroidism see symptoms in weight gain, sluggishness, sensitivity to cold, swollen joints and feeling low. Luckily, there are medical treatments that can help trigger the thyroid's activities again, and bring the body back to a steady metabolic rate. For such a little organ, the thyroid wields an awful lot of power. But a healthy thyroid manages our cells so effectively that it can keep us running smoothly without us even noticing it's there.
在你颈脖处有一个小器官 管辖着你体内很大的力量。 它被称为甲状腺。 就像公司的运营经理, 它的角色是确保你体内的细胞正常工作。 它通过激素来发送信息到每一个细胞。 这个高级器官是由小叶组成, 每个小叶包含更小的细胞, 称为卵泡, 它们储存着甲状腺 发送到你血液里的激素。 它生产的两个最重要的激素 是甲状腺素和碘甲状腺原氨酸, 或称为T3和T4。 作为信使,激素的工作 是指导每个在体内的细胞 何时消耗氧气和养分。 这个过程维持了身体的新陈代谢, 也就是我们的细胞通过 一系列的反应来供给我们能量的过程。 这个来自甲状腺的激素提示 使心脏更有效率的工作, 也使我们的细胞更快的分解养分。 如果你需要更多的能量, 甲状腺会发送激素来加快新陈代谢。 最终,甲状腺能让我们的细胞 使用能量,生长和繁殖。 甲状腺被脑下垂体控制, 它是在脑部深处监控甲状腺的腺体, 确保甲状腺知道何时送出信使。 脑下垂体的作用是 感知血液中激素含量, 是太高还是太低, 在此情况下它会以 促甲状腺激素的形式发出指示。 即使在这强有力的控制系统之中, 管理有时仍旧会出问题。 一些疾病, 甲状腺肿大, 或是体内化学物质不平衡 可能扰乱器官, 使器官无视脑下垂体的指示。 首先它会引起甲状腺功能亢进症, 是指器官发送出了太多的激素。 意味着细胞超载太多指示 来消耗养分和氧气。 结果是它们变的过度活跃, 也就是说一个有甲亢的人新陈代谢更快。 症状是高心率, 持续的饥饿和快速的体重下降。 他们也会感觉热,发汗, 焦虑和难以入睡。 与此相反的问题是甲状腺功能减退症, 也就是甲状腺送出的激素太少。 意味着体内细胞没有 足够的信使来指导它们。 结果是细胞生长缓慢和新陈代谢变缓。 有甲减的人表现出的症状包括体重增加, 低迷,易冷,关节肿大和感觉忧郁。 幸运的是,通过医学治疗 可以再次激发甲状腺的活动, 把身体带回到稳定的新陈代谢速率。 对一个这么小的器官而言, 甲状腺执掌着惊人的力量。 但是健康的甲状腺如此有效的 管理着我们的细胞, 我们的身体在正常运行时 却感觉不到它的存在。