OK, if you say so, Professor. And since you're in a scientific mood, how about answering today's quiz question. Which type of joint can you crack? Is it … a) fibrous? b) cartilaginous? Or c) synovial?

好吧，随你怎么说吧，大教授。既然你想学，那么就来回答一下今天测试题吧。人体哪一个可以被掰响？是a)纤维性? b)软骨性? c)滑液性?

Structurally speaking, you've got fibrous, cartilaginous, and synovial joints.

从结构上来说，你有纤维、软骨和滑。

They're caused by tiny bubbles in your synovial fluid, which is just the fancy name for the fluid in between your joints that keeps your bones from scraping together.

它们是由滑液中小气泡引起，滑液是之间防止骨骼刮擦液体别称。

The cartilage gets softer, weaker, and continues to lose elasticity, and starts to flake off into the synovial space, called joint mice.

软骨变得柔软、脆弱，弹力持续降低，开始脱落，进入滑囊内，称为“鼠”。

As " type A" cells in the synovium attempt to remove the debris, immune cells like lymphocytes and macrophages are recruited into the synovial membrane, which produces proinflammatory cytokines that ultimately cause inflammation of the synovium as well, called synovitis.

滑上A型细胞努力清除这些碎片同时，免疫细胞（如淋巴细胞、巨噬细胞）也被募集进入滑，产生炎症因子，最终导致滑炎。

These freely moveable synovial joints come in six different configurations that together allow pretty much any movement your body can make, from a subtle head nod to a vigorous jumping jack.

这些可自由移动滑有六种不同配置，它们一起让你身体得以做几乎任何运动，从轻轻点头到有力开合跳。

Well done! And synovial is the name for the fluid that surrounds this type of joint.

干得好！滑液是围绕在这类周围液体。

The synovium's composed of loose connective tissue, blood vessels, lymphatic vessels, and on the surface—" Type A" cells that clear cellular debris and " Type B" cells that produce components of synovial fluid, which helps lubricate the two articular surfaces.

滑由松散结缔组织、血管、淋巴管组成；在滑表面，A型细胞清理细胞碎屑，B型细胞产生滑液成分，滑液能够润滑两块表面。

But the family of joints that make all the sports, and the entire art of breakdancing, and yoga possible, are the freely movable synovial joints.

但是家族中使所有运动，霹雳舞和瑜伽整个艺术成为可能是可自由移动滑。

OK, this professor isn't feeling too clever today. I'm going to have to take a guess and say, c) synovial.

好吧，我这个教授今天大脑不是很灵光。我只能猜一下答案了，我选c)滑液性?

Yes, of course. So which type of joint can you crack? Is it … a) fibrous? b) cartilaginous? Or c) synovial?

当然。那么你能掰响哪一种？是a)纤维性? b)软骨性? c)滑液性?

The cool thing about these cavities is that they contain a bit of viscous, egg-white-like synovial fluid that acts like grease on a hinge.

这些空腔最酷一点是它们含有一点粘性、蛋清状滑液，就像铰链上油脂一样。

With Osteoarthritis, we're really talking about one particular kind of joint which is a synovial joint.

骨炎中，我们讨是一种特殊——滑。

These joints are synovial, meaning they have a joint capsule and a small amount of synovial fluid in between.

突是滑，即有囊，囊内有少量滑液。

Along with articular cartilage, another important component of synovial joints, and where they get their name from, is the synovium, which along with the surface of the articular cartilage, forms the inner lining of the joint space.

和软骨一样，滑是滑另一重要组成成分，所以得名“滑”；滑分布在软骨表面，形成腔内层。

They were also a compound called Cartilage Oligomeric Matrix Protein, or COMP, which can be a marker of arthritis if there's a bunch of it in your synovial fluid.

它们还是一种称为软骨寡聚基质蛋白（COMP）复合物，如果滑液中有很多这种蛋白，它可能是炎标志。

They started each session collecting a blood sample, and a bit of synovial fluid, the natural lubricant inside the knee joint.

他们在每次训练开始时采集血样和少量滑液，滑液是膝内天然润滑剂。