Renal system additional information

Box for juxtaglomerular apparatus: It is a specialized structure formed by the afferent arteriole and the macula densa. It is made of three types of cells as follows:

i) Juxtaglomerular or JG cells: These are specialized smooth muscle cells that produce renin. These cells cluster together around the afferent arteriole forming a cuff and have prominent renin containing granules.

ii) Macula densa: They are modified cells of the distal convoluted tubule; they are taller than other cells of the DCT and have crowded nuclei.

iii) Lacis cells or cells of Goormaghtigh: They are extraglomerular mesangial cells

Nutcracker syndrome: It results from the compression of the left renal vein between the abdominal aorta and the origin of the superior mesenteric artery. This happens when the SMA arises from the aorta at an acute angle. Rarely, a posterior Nutcracker syndrome has been described when the renal vein courses posterior to the aorta and gets compressed between the abdominal aorta and the vertebral body. The syndrome presents with hematuria, abdominal or flank pain, left-sided varicoceles, chronic pelvic pain, orthostatic proteinuria, etc. Symptoms are aggravated by physical activity.