Question

why may certain cells have preponderance of certain organelles??
:-)

Answer 1

"structure -> function"
adrenal medulla cells have many secretory granules because they're storing epinephrine and norepinephrine to be secreted when stimulated
adrenal cortical cells have well-developed smooth endoplasmic reticulum cause they're involved in steroid synthesis
...

Answer 2

muscle cells are replete with mitochondria to have an abundance of ATP for muscle contraction.