Page 705 - Atlas of Histology with Functional Correlations

proximal tubules (14) are very similar to the proximal convoluted tubules (1),

and the straight (ascending) segments of the distal tubules (6) are similar to distal
convoluted tubules (2, 4). The collecting tubules (12) in the cortex are distinct
because of their lightly stained cuboidal cells and distinct cell membranes.

The medulla contains only straight portions of the tubules and the segments
of the loop of Henle (thick and thin descending segments and thin and thick

ascending segments). The thin segments of the loops of Henle (15) are lined
with a simple squamous epithelium and resemble the capillaries (13). The
distinguishing features of the thin loops of Henle (15) are the thicker epithelial
lining and the absence of blood cells in their lumina. In contrast, most capillaries

(13) have blood cells in the lumina.

Also visible in the cortex are the interlobular blood vessels (3) and the
larger interlobar vein and artery (7). The interlobular blood vessels (3) give
rise to the afferent glomerular arteriole (11) that enters the glomerular capsule
(5b) at the vascular pole (8) and forms the capillary tuft of the glomerulus (5a).

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