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.
If you were to cut a kidney in half, you would see the following parts: Renal capsule - a thin, outer membrane that helps protect the kidney. Cortex - a lightly colored outer region. Medulla - a darker, reddish-brown, inner region. Renal pelvis - a flat, funnel-shaped cavity that collects the urine into the ureters.