Answer to Question #61933 in Human Anatomy and Physiology for Sanjukta Ghosh

Question

Could you tell me if adrenaline and noradrenaline have differences in function.I'm having a book that says that epinephrine and norepinephrine do have some major differences in function (like epinephrine increases systolic pressure while norepinephrine increases both systolic and diastolic pressures) but other sources suggest that they do not. This has lead to some confusion and I'm looking for some authentic sources.It will be kind if you shared your opinion on this part.

Answer 1

Noradrenaline and adrenaline are catecholamines that play major roles in regulation of the ‘inner world’ of the body by the brain. Noradrenaline (synonymous with norepinephrine), the main neurotransmitter of the sympathetic nervous system, is responsible for tonic and reflexive changes in cardiovascular tone. Adrenaline is a key determinant of responses to metabolic or global challenges to homeostasis, such as glucoprivation, and of manifestations of emotional distress.
In contrast with the view that the sympathetic nervous and adrenomedullary hormonal systems function as a unit (the ‘sympathoadrenal system’) to maintain homeostasis in emergencies, across a variety of situations adrenaline responses are more closely linked to responses of the hypothalamic‐pituitary‐adrenocortical system than of the sympathetic nervous system. The sympathetic noradrenergic system is active even when the individual is at rest and maintains tonic levels of cardiovascular performance. Adrenoceptors in the membranes of effector cells determine the physiological and metabolic effects of catecholamines.