20.3 The upper urinary tract: development of the metanephros



Functional development

Quiz

Quiz 05


Quiz

Quiz 24


At birth the kidneys have a multilobular appearance, due to the development of the ureter anlage in the metanephric blastema. Normally, towards the end of the fetal period, the lobes are considerably smoothed, but they still exist until after birth.
Completion of the smoothing follows during childhood by the increase in volume of the connective tissue and the increase in size of the nephrons without any change in their number. With only few exceptions, adult kidneys no longer exhibit any lobulation.
Since the renal architecture is finalized between the 5th and 15th weeks of intrauterine development; organogenesis of the kidneys lasts well beyond the embryonic phase until far into the fetal period.

Fig. 13 - Development of the
smooth kidney surface
 Legenda

1
2
3
Renal medulla
Calix minor
Renal cortex

Fig. 13
In humans renal lobulation is easily seen only in the embryonic and fetal periods, but can extend into childhood.
At birth, however, it is strongly attenuated.
In adults, the cortical zones of the individual lobes, "A to E", fuse and the smoothing of their depressions leads to a smooth and uniform renal surface structure.


Fig. 14 - Anatomy of the kidney at the end of its development  Legenda

1
2
3
4
5
6
Ureter
Renal pelvis
Vena renalis
Arteria renalis
Major calix
Minor calix
7
8
9
10
11
12
13
Cortex
Capsula renis
Medullary rays
Papilla renalis
Sinus renalis
Columna renalis
Medullary pyramid

Fig. 14
The renal parenchyma is divided into an outer cortical zone and an inner medullar zone. In its interior the kidney has a hollow space, the renal sinus, into which the papillas intrude and where the trunks of the renal vessels are found.

Meer info

Histology


Quiz

Quiz 12



Fig. 15 - Vascular supply of the kidney at the end of the development  Legenda

10
14
15
16
17
18
Papilla renalis
Interlobar artery
Interlobar vein
Arcuate artery
Arcuate vein
Interlobular arteries and veins

Fig. 15
Detail of the vascular supply of a renal lobe. One sees the renal pyramid surrounded by the interlobar vessels as well as their continuations, the arcuate vessels. From them originate the interlobular vessels that form the afferent arterioles, followed by a capillary network (glomerulus; not shown here).






Quiz

Quiz 06



Previous page | Next page