Page 717 - Atlas of Histology with Functional Correlations

and sections of an erythrocyte (7) and a leukocyte (9). In the lumen of the

capillary (6, 8) are also visible tiny fenestrations in the endothelium
(arrowheads).

FIGURE 18.10 ■ Kidney: transmission electron micrograph of a podocyte and
adjacent capillaries in the renal corpuscle. ×6,500.

FIGURE 18.11 | Kidney Medulla: Papillary

Region (Transverse Section)

The papilla in the kidney faces the minor calyx and contains the terminal
portions of the collecting tubules, now called the papillary ducts (3). The
papillary ducts (3) exhibit large diameters and wide lumina and are lined with
tall, pale-staining columnar cells. Also present in the papilla are the straight

(ascending) segments of the distal tubules (7, 10) and the straight
(descending) segments of the proximal tubules (1, 6, 11). The straight
segments in the medulla are very similar to the convoluted tubules in the cortex.
Interspersed among the ascending (7, 10) and descending straight tubules (1, 6,

11) are the transverse sections of the thin segments of the loop of Henle (5, 8)
that resemble the capillaries (4, 9) or small venules (2). The capillaries (4, 9)
and the small venules (2) differ from the thin segments of the loop of Henle (5,
8) by thinner walls and by blood cells in their lumina.

The connective tissue (12) surrounding the tubules is more abundant in the

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