So, bone resorption usually overtakes bone formation around the 8th decade of life.

因此，人到80岁之后，骨吸收能力通常压制骨生长能力。

Finally, vitamin D promotes calcium absorption in the gut, so it increases serum calcium, promoting bone formation and decreasing bone resorption.

最后，维生素D促进钙在肠内的吸收，因此增加了血清钙的水平，促进骨生长并减弱骨吸收。

Alright, as a quick recap, osteoporosis refers to decreased bone density, on account of increased bone resorption compared to bone formation.

好！快速回顾一下：骨质疏松意味着骨密度的降低，由自身骨吸收能力大于骨生长能力造成。

We believe that this bone formation in Repetosaurus' skin was used to store minerals like calcium.

我们相信，在 Repetosaurus 的皮肤中形成的这种骨骼结构被用来储存钙等矿物质。

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。

Bones even help maintain homeostasis by regulating blood calcium levels and producing the hormone osteocalcin, which regulates bone formation and protects against glucose intolerance and diabetes.

骨骼甚至通过调节血钙水平和产生激素骨钙素来帮助维持体内平衡，骨钙素调节骨骼形成，防止葡萄糖耐受不良和糖尿病。

This ends up causing new bone formation and the medullary cavites of the skull can expand outward, which causes enlarged cheeks and a " hair-on-end" appearance on skull x-ray.

这最终导致新骨形成，及颅骨髓腔可能向外扩展，在头颅X线上表现为增大的脸颊以及“竖发征”。

But, for reasons that we don't understand yet, the osteoclasts actually increase their rate of bone resorption in low gravity, while the osteoblasts dial back on the bone formation.

但是，由于我们还不明白的原因，破骨细胞实际上在低重力下增加了骨吸收的速度，而成骨细胞则减少了骨的形成。

On the other hand, calcitonin is produced by the thyroid gland in response to high serum calcium, so it opposes the action of PTH - therefore promoting bone formation and decreasing bone resorption.

另一方面，当血清中钙含量较高时，甲状腺释放降血钙素，来制约甲状旁腺激素的作用，从而促进骨骼的形成并减缓骨骼的吸收。

Salt has several very important functions: it's needed by the heart to pump blood properly, it's needed by the stomach to facilitate digestion, and it is necessary for bone formation and bone strength.

盐有几个非常重要的功能：心脏正常泵血，促进胃消化都离不开盐，而且盐对骨骼形成和骨骼强度是必不可少的。