Juxtaglomerular apparatus arterioles

Tubuloglomerular feedback. Tubuloglomerular feedback involves the activity of the juxtaglomerular apparatus (see Figure 19.1). This structure is located where the distal tubule comes into contact with the afferent and efferent arterioles adjacent to the glomerulus. The juxtaglomerular apparatus is composed of the following ... 

Figure 29.2. Schematic representation of nephron and vasculature. The glomerulus is positioned between afferent and efferent arterioles, and the juxtaglomerular apparatus is the point of contact between the vascular pole and distal tubule of the nephron. A capillary network surrounds tubular structures. (From Guyton, A. C., and Hall, J. E., Textbook of Medical Physiology, 11th ed. Elsevier Saunders Company, Philadelphia, 2006. Reproduced with permission.)...

The basement membrane has collagen and glycoproteins as its major constituents. Anionic regions present on the basement membrane influence the filtration of molecules. The juxtaglomerular apparatus located at the hilus of the glomerulus consists of three parts. These are the macula densa, which is a small segment of the distal tubule near the afferent arteriole, the epithelioid cells, which are the site of renin synthesis, and the lacis cells located in the region between the macula densa and the afferent and efferent arterioles (Fig. 3). 

Fig. 9-7. Hyperplastic juxtaglomerular apparatus in renovascular hypertension. The juxtaglomerular cell mass (polar cushion) is at the hilus of the glomerulus, next to the macula densa and between the afferent arteriole (which enters the glomerulus here on the right side) and the efferent arteriole (which is not in the plane of this section). Instead of its normal 6 to 8 cells, this polar cushion contains over 30 cells. Hematoxylin and eosin stain, x 520. (Supplied by Harrison Latta)...

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