the afferent arteriole contains cells called
The afferent arteriole in this region contains specialised secretory cells (smooth muscle cells) called juxtaglomerular cells, that secrete renin. These cells do two things: 1  They monitor blood pressure, by measuring how much the arteriole wall is stretched.he afferent arteriole in this region contains specialised secretory cells (smooth muscle cells) called juxtaglomerular cells, that secrete renin. These cells do two things: 1  They monitor blood pressure, by measuring how much the arteriole wall is stretched.