What are the primary components of the juxtaglomerular apparatus? check all that apply?

The juxtaglomerular apparatus is a structure (formed by the distal convoluted tubule and the glomerular afferent arteriole) with the function in the regulation of blood pressure and the filtration rate of the glomerulus. Its primary components are:
·     the macula densa- specialized epithelial cells in the distal convoluted tubule (detect Na concentration),
·     juxtaglomerular cells- formed from the smooth muscle cells of the afferent arteriole (secrete renin),
·     extraglomerular mesangial cells (lacis cells)-unknown function.