norepinephrine hormone pathway

norepinephrine brain noradrenalin noradrenaline neurotransmitter pathway hypothalamus system stress pituitary adrenal hormone response cortex vector axis anxiety body therapy endocrine gland function hypothalamic scheme secretion endocrinology anatomy epinephrine neurochemical science medical structure illustration biology medicine health human organ diagram chemistry head flat nucleus accumbens globus pallidus tail amygdala pons cerebral