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.
The cortex is the superficial outer layer of the kidney located underneath the capsule. The medulla is the inner layer and it extends from the renal cortex to the renal sinus. The medulla is divided into various cone-shaped structures called the renal pyramids.tructures such as the renal veins, artery, nerves and lymphatic vessels are located in the renal hilum. The renal sinus is a fat-filled cavity inside the kidney that extends from the hilum. At the hilum the ureters also exit the kidney. The kidney is covered by a fibrous renal capsule.