Now, before we dive too far in here, let's re-draw the nephron so that the structure of the renal tubule is a little more accurate.

现在，趁还没有学得更深，我们来画一个肾单位，让肾小管的结构更加精确。

Really, though, you're much more likely to experience pain in response to cold or hot things which contract or expand the fluid in those tubules than you are in response to sugar.

不过，和对糖的反应相比，你更有可能在对冷或热的东西作出反应时体验到疼痛，这些东西导致这些小管中的液体收缩或膨胀。

The underlying cause is hyperuricemia— too much uric acid in the blood, which results in the formation of sharp, needle-like crystals, in areas with slow blood flow like the joints and the kidney tubules.

引起痛风的原因是高尿酸血症，即血液中的尿酸含量过高，过多的尿酸在血流缓慢的地方，如关节腔和肾小管，形成尖锐的细针样结晶。

Another example is Fanconi syndrome, which is where the proximal convoluted tubule essentially loses its capacity to reabsorb a variety of solutes - including phosphate - once again letting it get excreted in the urine.

另一个例子是范可尼综合征，即近曲小管基本上失去了重新吸收各种溶质（包括磷酸盐）的能力，导致磷酸盐通过尿液排出。

If Leptospira gets to the kidneys, it may infect the interstitium, causing interstitial nephritis, or it may cause an inflammatory reaction that damages the renal tubules, resulting in acute tubular necrosis.

如果钩端螺旋体进入肾脏，它染肾间质而引起间质性肾炎，也能引发炎性反应损伤肾小管，导致急性肾小管坏死。

That's the stage when individuals usually experience pain, although pain can also occur when the caries lesion involves the dentin layer since sensory nerve fibers travel through tubules in the dentin.

在这个阶段，患者到疼痛，但牙本质层受累产生龋坏时也可能有疼痛产生，因为觉神经也分布在牙本质的管道中。

These pumps drive potassium from the blood into the cells and from there it flows down its concentration gradient into the tubule to be excreted as urine.

这些泵驱使钾从血液进入细胞内，细胞内的钾离子再顺着浓度梯度进入肾小管，以尿液形式排泄。

Macula densa cells are located in the distal convoluted tubule and they can sense when levels of sodium and chloride are low.

致密斑位于远曲小管，可以受到钠和氯水平降低。

Beneath that is the medulla, a set of cone-shaped masses of tissue that secrete urine into tiny sac-like tubules.

髓质下面是一组锥形组织，将尿液分到微小的囊状小管中。

If your enamel is worn away, your dentin and its tubules can be exposed.

如果你的牙釉质被磨掉了，你的牙本质和它的小管就暴露出来。

Each nephron consists of a round renal corpuscle that resides up in the cortex, followed by a long and winding renal tubule that loops around between the cortex and the medulla.

每个肾单位由一个位于大脑皮层的圆形肾小体组成，其次是一个长而弯曲的肾小管，在大脑皮层和髓质之间循环。

These tubules are important for sensory nerves as well, which use them to travel through the dentin from the pulp to the dentin-enamel junction.

牙本质中的小管对觉神经也很重要，因为觉神经可以通过它们从牙髓到达本釉质交界处。

ADH affects the last two-thirds of these tubes, called the distal convoluted tubule and the collecting ducts.

ADH作用于这些小管的终末2/3部分，即远曲小管和集合管。

Within each kidney, there are about 1 million nephrons, and each nephron is made up of a renal corpuscle and a renal tubule.

每个肾约有100万个肾单位，每个肾单位由肾小体、肾小管组成。

This kind of intrinsic control, or autoregulation, is helpful in controlling the filtration rate through normal ranges of blood pressures, but the kidneys mostly regulate urine concentration at the other end of the nephron tubules.

这种内在控制或自动调节有助于通过正血压范围控制过滤率，但肾脏主要调节肾小管另一端的尿液浓度。

These two make their way to the nephron of the kidney, and at this point in the proximal convoluted tubule, phosphate usually gets reabsorbed back into the blood via sodium-phosphate cotransporters.

随着这一对离子进入肾脏的肾单位之中，在近曲小管处，磷酸盐通被重新吸收，经由钠-磷协同转运蛋白重新入血。

The odontoblasts have long processes, or arms, that lay within tiny tubules in the dentin - like an octopus sticking it's arms through a block of cement.

成牙质细胞有长长的突起，或者说长臂，伸入牙本质中的小管，就像章鱼的触角伸进水泥块被困住一样。

So when ADH is low, most of the water flows through the the distal convoluted tubule and the collecting duct, giving us diluted urine.

所以当血中ADH水平低时，大部分水就顺着远曲小管和集合管排出体外，尿液也就被稀释。

It contains microscopic, fluid-filled tubules that run from the pulp to the underside of the enamel.

它包含微小的、充满液体的小管，从牙髓一直到牙釉质下层。

That leaves 13% of the initial amount, and at this point the distal tubule and collecting ducts of the nephron can either reabsorb or secrete potassium depending on what the body needs.

余下原始量的13%，此时肾单位的远曲小管和集合管，依据机体的需要，或重吸收，或分出钾。