A nephron of the kidney. from Gray's Anatomy 1918. The illustration includes an important anatomical error in that it fails to depict the  distal tubulus (<i>tubulus rectus distalis</i>) passing by vascular pole of the glomerulus before becoming the distal convoluted tubule (<i>tubulus contortus distalis</i>). The distal tubulus together with the afferent arteriole (<i>arteriola afferens</i>) and the extra glomerular mesangial cells together make up the <a href="https://en.wikipedia.org/wiki/juxtaglomerular_apparatus" class="extiw" title="en:juxtaglomerular apparatus">juxtaglomerular apparatus</a>. This occurs in all nephrons but was not known in 1918.
<a href="https://en.wikipedia.org/wiki/Henry_Gray" class="extiw" title="en:Henry Gray">Henry Gray</a>
1918
<a rel="nofollow" class="external text" href="https://archive.org/stream/anatomyofhumanbo00grayrich#page/1222/mode/2up">Grey's Anatomy</a>, p. 1223