Q. What is the use of Adrenergic Receptor?
Adrenergic Receptors are also subdivided into 2 major categories: ALPHA α - or- BETA β
In general, when NE (E) binds to alpha receptors -> excitatory
beta receptors -> inhibitory (with notable exceptions: heart β1)
Beta-1 receptors are found on heart -> NE (E) stimulates HR and SV
Beta-2 receptors are found on lungs and some viscera -> (-) NE serves to dilate airways and slow down GI tract activity. Note that non-specific β (1,2) blockers decrease HR and BP, but can also constrict airways (undesirable effects).