The extraglomerular mesangial cells help with the signalling between macula densa cells and juxtaglomerular cells.

球外系膜细胞辅助致密和球旁细胞的信息传递过程。

Now there's a specialized region within the retina known as the macula.

视网膜内有一个特殊区域，称为。

Then it travels through the lens, which helps to direct the light raise into the macula, which is the back part of your retina.

然后它穿过晶状体，这有助于引导光线进入，就是视网膜的后面。

This is because the part of the occipital lobe in charge of the macula gets blood from both the posterior cerebral artery as well as the medial cerebral artery.

这是因为负责功能的枕叶部分同时由大脑后动脉和大脑中动脉供血。

So, in the case of hypovolemia and hypotension, the macula densa cells sense the low sodium and chloride levels and send a signal over to the juxtaglomerular cells which are located in the wall of the afferent arteriole.

因此，当血容量减少、低血压时，致密感受到钠、氯含量降低，传递信号给位于入球小动脉血管壁上的球旁细胞。