Final answer:
The renal pyramids are separated by extensions of cortex-like tissue known as renal columns, which contain blood vessels and connective tissues, and divide the kidney into lobes.
Step-by-step explanation:
The renal pyramids are separated by extensions of cortex-like tissue called the renal columns. The renal columns are extensions of the renal cortex that reach into the renal medulla. They serve to separate the renal pyramids and contain blood vessels and connective tissues.
These columns are important in the internal structure of the kidney because they provide a supportive framework for blood vessels that enter and exit the cortex, and they also divide the kidney into lobes. Each lobe is composed of a renal pyramid and the adjoining cortical region that forms the functional unit where urine is collected before it proceeds to the ureter.