How are norepinephrine and epinephrine related in their function?

Norepinephrine and epinephrine are closely related in their function as both are catecholamines that play a significant role in the body's response to stress. When faced with a stressor, the body releases these hormones, leading to physiological changes that prepare an individual for 'fight or flight' situations. This includes increased heart rate, elevated blood pressure, and enhanced blood flow to muscles, all of which are crucial for responding effectively to threats. Both hormones act on the sympathetic nervous system and have similar effects on various target organs, reinforcing their role in managing stress responses.

The other options do not accurately capture the primary functions of norepinephrine and epinephrine. While regulating sleep and appetite is an important function of certain neurotransmitters, it is not the primary role of these hormones. Similarly, while they may influence nerve impulses, neither act in a strictly inhibitory or stimulatory manner as described in the options. Lastly, muscle control is primarily managed by other neurotransmitters, and while norepinephrine and epinephrine may affect muscle readiness during stress, they are not directly responsible for muscle control itself.