Ok, now let's have a quick look at parathyroid hormone.

好，来看甲状旁腺的功能。

This affects the amount of parathyroid hormone that gets released by the parathyroid gland.

这从而会影响甲状旁腺释放甲状旁腺激素的量。

If osteoporosis is really advanced, teriparatide, a recombinant parathyroid hormone can be used.

如果骨质疏松十分严重，可以使用特立帕肽这种重组甲状旁腺激素治疗。

Additionally, parathyroid hormone can boost 1-alpha-hydroxylase activity, which forms more active vitamin D, increasing gut absorption of calcium.

此外，甲状旁腺激素可以增加1-α-羟化酶的活性，从而形成更多有活性的维生素D，增加肠道对钙的吸收。

It turns out, though, that parathyroid hormone also shuts this down.

不过，事实证明甲状旁腺激素也会阻止这种反应。

To identify the cause, lab tests are typically done, which includes tests for parathyroid hormone, vitamin D, albumin, phosphorus, and magnesium.

为了确定病因，通常要做实验室检查，其中包括甲状旁腺激素、维生素D、白蛋白、磷和镁的检测。

Now, that calcium's still in the lumen, but parathyroid hormone also affects the distal convoluted tubule and increases calcium reabsorption.

这时，钙仍然在腔内，但甲状旁腺激素也会影响远曲小管，增加对钙的再吸收。

Lastly, parathyroid hormone increases calcium reabsorption and reduces the reabsorption of phosphate from the kidneys, so more phosphate is excreted through the urine.

最后，甲状旁腺激素可以促进肾脏对钙的重吸收，而减少对磷酸盐的重吸收，因此导致尿磷升高。

Now, the levels of calcium and phosphate in the bone, but also in the blood, are regulated by vitamin D and parathyroid hormone, or PTH.

钙和磷不仅存在于骨中，也存在于血液中，钙磷含量的调节受维生素D和甲状旁腺激素（PTH）调控。

As calcium levels in the blood fall, parathyroid hormone is released, causing the bones to lose calcium.

随着血钙降低，甲状旁腺激素释放，导致溶骨作用。

Less calcium entering the blood is the most common cause and can be due to hypoparathyroidism, or lower levels or lower activity of parathyroid hormone.

钙离子进入血液的量减少是最常见的原因，可能是由于甲状旁腺功能减退或者甲状旁腺激素的量或者活性降低。

Related to this is pseudohyporparathyroidism, which is where the kidneys simply don't respond to parathyroid hormone because of a genetic defect in the parathyroid hormone receptor.

与此相关的是伪甲状旁腺功能减退症，也就是由于甲状旁腺激素受体的基因缺陷，肾脏不对甲状旁腺激素作出反应。

Parathyroid hormone is produced by the parathyroid glands in response to low serum calcium, and it increases bone resorption to release calcium into the bloodstream.

顾名思义，甲状旁腺激素在甲状旁腺产生，来应对血清中过低的钙水平，从而增加骨质的吸收来释放更多的钙进入血液。

Now, that calcium's still in the lumen, though, but parathyroid hormone also affects the distal convoluted tubule and increases calcium reabsorption.

现在，钙仍然在腔内，但是甲状旁腺激素也会影响远曲小管增加钙的再吸收。

Also, people with the genetic disease DiGeorge syndrome, often born with parathyroid glands that are too small and can't produce enough parathyroid hormone.

或是由于患有DiGeorge综合症，生来甲状旁腺就太小，不能产生足够的甲状旁腺激素。

Now, even though parathyroid hormone stimulates bone resorption, it's been found that intermittent injections with teriparatide activates osteoblasts more than osteoclasts, therefore increasing bone formation.

其实，即使甲状旁腺激素刺激骨吸收，研究发现间歇性注射特立帕肽激活了更多造骨细胞而非破骨细胞，从而增强骨生长。

This can result in conditions like primary hyperparathyroidism which result in too much parathyroid hormone, which leads to excess phosphate being excreted in the urine.

这可能引发原发性甲状旁腺功能亢进，会造成甲状旁腺激素过多，导致过多的磷酸盐从尿液中排出。

Parathyroid hormone is secreted in response to low blood calcium levels, and it stimulates the resorption of calcium and a small amount of phosphate from the bone and into the bloodstream.

在血钙降低时，甲状旁腺激素分泌增加，刺激钙的重吸收，并且使一小部分磷酸盐从骨中入血。

If calcium levels fall, the four parathyroid glands buried within the thyroid gland release parathyroid hormone which frees up both calcium and phosphate ions from the bones.

如果钙水平下降，那么在甲状腺内的四个甲状旁腺释放甲状旁腺激素，导致骨骼中释放钙和磷酸盐离子。

Bone remodelling as a whole is highly dependent on serum calcium levels, which, in turn, are kept in the normal range by a balance between parathyroid hormone, or PTH, calcitonin and vitamin D.

整个骨重建进程高度依赖于血清中钙的含量，而将血清中钙的含量维持在正常值范围内是由甲状旁腺激素、降血钙素与维生素D间的制约平衡所控制的。