Which nervous system is classified as adrenergic?

The sympathetic nervous system is classified as adrenergic because it primarily utilizes adrenergic neurotransmitters, most notably norepinephrine (noradrenaline), to mediate its effects throughout the body. When activated, the sympathetic nervous system prepares the body for "fight or flight" responses, leading to changes such as increased heart rate, bronchodilation, and enhanced blood flow to muscles, all facilitated by the action of adrenergic receptors that respond to norepinephrine and epinephrine.

This classification is important in understanding how the body responds to stress and the pharmacologic management of conditions like hypertension or heart failure, where adrenergic mechanisms might be targeted therapeutically. The other systems listed are classified differently; for example, the parasympathetic nervous system is primarily cholinergic, using acetylcholine as its key neurotransmitter.