Althoug inhaling air containg the gas __ can be deadly, the verberate body produces samll amts of __, some of which act as neurotransmitters. __ is generated by the enzyme __, one form of which is found in certain populations of neurons in the brain and PNS. In the brain, __ regulates the release of hypothalamic hormoes. In the PNS, it acts ans an inhibitory neurotransmitter htat hyperpolarizes interstinal smooth musscle cells.
carbon monoxide (CO) x all