1. Immediate Regulation (Seconds to Minutes)
This is managed by the
nervous system
to respond quickly to changes in blood pressure.
Baroreceptor Reflex
:
Baroreceptors
in the carotid sinus and aortic arch sense changes in blood pressure.
When blood pressure is high, they send signals to the brain (medulla oblongata), which:
Decreases heart rate
(via parasympathetic stimulation).
Dilates blood vessels
(reduces vascular resistance).
When blood pressure is low, the brain:
Increases heart rate and contractility
(via sympathetic stimulation).
Constricts blood vessels
(raises vascular resistance).
Chemoreceptor Reflex
:
Chemoreceptors in the carotid and aortic bodies detect changes in oxygen, carbon dioxide, and pH levels, indirectly affecting blood pressure.
Regulation of Blood Pressure