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.
urinary bladder. The urinary bladder is a temporary storage reservoir for urine. It is located in the pelvic cavity (see pelvis), posterior to the symphysis pubis, and below the parietal peritoneum. The size and shape of the urinary bladder varies with the amount of urine it contains and with pressure it receives from surrounding organs.