Final answer:
The most superficial internal region of the kidney that contains parts of most nephrons is the renal cortex.
Step-by-step explanation:
The most superficial internal region of the kidney that contains parts of most nephrons is the renal cortex. The renal cortex is the outerpart of the kidney that contains all of the nephrons, while some nephrons also have loops of Henle that extend into the medulla. The renal medulla consists of the renal pyramids, which are separated by extensions of the renal cortex called renal columns.