I remember being told that the brain had two messenger systems, the peripheral nervous system and the endocrine system, the first being fast and having very specific effects the second being slower and often having more general or systematic effects. This is partially true I suppose but its much more complicated, first there are hormones that are independent of neural control, we can ignore them. The secretion of many hormones is directly controlled by the brain, in fact some glands are derived from neural germ cells including the posterior pituitary, the pineal gland. and the adrenal medulla, but the main regulation is by the anterior pituitary gland which controls glands all around the body. In fact the hormones it releases are mostly synthesised in the hypothalamus. Hormones can have a range of effects which might seem very different in the body from their effects in the brain and many hormones cannot cross the blood brain barrier. There are hormones like Nor-epinephrine which act as hormones in the body but are also neurotransmitters in the brain, there are a group of hormones only really found in the brain (neuro-hormones), some influence neural firing (neuro-modulators) and others that can cause some fundamental changes over a long period of time (like the sex hormones).
I think the publicity around stress and anxiety makes people think of these fairly rapid reactions and its right that the two messenger systems work together, often in quite complex ways but remember they often do very different jobs in the body.
I think the more we learn about neuro-chemistry it simply emphasises that we have no real understanding of how it all comes together but I think a good guiding principle is whenever you read something that says this neurotransmitter does this or this hormone has this effect, its rubbish, none of these things work in isolation, its live every neurone is sat in a neuro-chemical soup with up to 10,000 other neurones with direct connections, trying to influence when it might fire.