Detectable fall in blood pressure occurs in
Baroreceptor stimulation results in the activation of two mechanisms.
1.    Stimulation of cardiovagal inhibitory centre- Nucleus ambiguous- Leads to Bradycardia.
2.    Inhibition of vasomotor centre- Rostral ventrolateral medulla- Leads to decreased BP.
Sympathetic stimulation
Inhibition of VMC
Disinhibition of VMC
Stimulation of vagal centre