Isotopes when written out are common nouns, and should begin with the uncapitalized element name, followed by a hyphen (not an em dash or en dash) and then the mass number. Examples are carbon-14 and uranium-235.
The central region of the kidney contains the renal pelvis, which is located in the renal sinus, and is continuous with the ureter. The renal pelvis is a large cavity that collects the urine as it is produced. The periphery of the renal pelvis is interrupted by cuplike projections called calyces.
Renal pelvis: funnel-shaped portion of the ureter in the kidney; Hilum: a section that is the entry point to the kidney for the renal veins, renal arteries, and ureter; At the tip of each nephron is a small sac of capillaries called the glomerulus. There, under tight pressure, materials are constantly being filtered out of the blood.