The pituitary gland is known as the "master gland" because it is known to control hormones that regulate several other important systems in the endocrine system such as the thyroid gland, ovaries, and testes.
The atom? gas? either one of those two would work
D, contains fluid that becomes more concentrated as it moves down into the medulla
I think it's when glycogen turns glycogen into glucose and vice versa. Not too sure though.