The first step in a cascade is a result of:

neurohormones.%0D%0A%0D%0Aneurohormones.%0D%0A%0D%0Athe adrenal gland.%0D%0A%0D%0Athe adrenal gland.%0D%0A%0D%0Athe hypothalamus.%0D%0A%0D%0Athe hypothalamus.%0D%0A%0D%0Athe thyroid or parathyroid.

The first step in a cascade is a result of the hypothalamus.