A transverse section of the adult spinal cord shows white matter in the periphery, gray matter inside, and a tiny central canal filled with CSF at its center. Surrounding the canal is a single layer of cells, the ependymal layer.
Cortisol is commonly referred to as the stress hormone.. The hormone is secreted by the adrenal glands and released into the bloodstream as a fight or flight response to stress. The highest quantities of cortisol are produced in the early morning hours and then production slowly tapers off throughout the day.
Cortisol: Stress Hormone. Cortisol is a glucocorticoid hormone synthesized from cholesterol by enzymes of the cytochrome P450 family in the zona fasciculata, the middle area of the adrenal cortex (9). Regulated via the HPA axis, cortisol is the primary hormone responsible for the stress response. Expressed at the highest levels in the early morning, cortisolâs main function is to restore homeostasis following exposure to stress (10).