The thin part simply means the size of our epithelial cells within this section are small. These cells are thin, they're relatively small, while this is our thick ascending loop of Henley. And thick means our size of the cells is relatively large. The epithelial cells are relatively thick. Now, the reason we divide the Loop of Henley into these three segments is because each one of these sections carries out its own unique function. Now, before we examine the individual function of these three segments, let's discuss what the overall function of the Loop of Henley is.