Lectures on renal & urinary diseases / by Robert Saundby.

Robert Saundby

Date:: 1896

Credit: Lectures on renal & urinary diseases / by Robert Saundby. Source: Wellcome Collection.

20/466 page 2

$anatomists into two parts, — a boundary zone consisting of the broader portions of the pyramids, and a papillary portion, constituted by the projecting apices. The relative proportions of these three divisions are, accord- ing to Klein, Cortical Layer - - - 3'5 Boundary Zone - - . . . 2-5 Papillary Portion - - - - - 4-0 The structure of the cortex is sHghtly granular from the presence of the Malpighian bodies, while it is marked by hghter Hnes at right angles to its surface. The medullary rays, or pyramids of Ferrein, are conical bundles of straight tubules running from the cortex into the medulla. Between the medullary rays are the interlobular vessels, the Malpighian bodies, and the convoluted tubules, together form- ing the labyrinth. The medulla is distinctly striated by alternating light and dark lines arranged fan-wise, the handles of the fans being at the apices of the pyramids. The whitish lines are bundles of straight tubes, the darker lines blood vessels. In the fcetus the kidney is distinctly lobulated, each lobule consisting of a pyramid of Malpighi with its corresponding cortical portion. In the adult this iobulated condition persists only rarely, but the connection between each pyramid and the uriniferous tubules and blood vessels of its cortical portion always remains {^Fig. 3). The uriniferous tubules take origin in Bowman's capsules, membranous expansions of their extremities, measuring of an inch in diameter. They pursue a tortuous course, effect junctions with one another, and ultimately form large collect- ing tubes which open on the apices of the papilla. Each tubule is formed of a homogeneous basement membrane lined by epithelial cells, with an axial space or lumen for the passage of urine. Fig. I represents the course of a uriniferous tubule. Con- nected by a narrow neck (2) with Bowman's capsule (i) is the proximal convoluted tubule (3), which ultimately leaves the labyrinth and passes down the medullary ray into a pyramid. Before leaving the labyrinth its convoluted appearance be- comes less pronounced, and it is called a spiral tubule (4) ; descending, it narrows very much, finally turning at Henle's loop (6), the descending and ascending portions being called$

Lectures on renal & urinary diseases / by Robert Saundby.

Licence and re-use

Contents