Question

norepinephrine (ne) multiple choice always has an inhibitory effect on the effector. has either an excitatory or inhibitory effect on the effector. always has an excitatory effect on the effector.

Explanation:

Norepinephrine (NE) is a neurotransmitter and hormone. Its effect on effectors (like target cells or organs) depends on the type of receptor it binds to. For example, binding to alpha - adrenergic receptors can have excitatory effects (e.g., vasoconstriction), while binding to certain beta - adrenergic receptors in some contexts can have inhibitory effects (e.g., on smooth muscle in the gut). So it does not always have just an excitatory or just an inhibitory effect, but can have either depending on the receptor and the effector.

Answer:

The correct option is: has either an excitatory or inhibitory effect on the effector.