Vasomotor Center
| Overview |
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- The Vasomotor Center receives inputs from the baroreceptors as well as higher-order brain centers and makes a regulatory decision regarding the value of the systemic arterial pressure. It then coordinates its response by modulating the autonomic nervous system as described in Systemic Arterial Pressure - Autonomic Control.
| Location |
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- The Vasomotor Center is located in the brainstem's medulla and lower pons. It receives neural inputs directly from the baroreceptors as well as higher-order neural centers from throughout the brain.
| Regulation |
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- The vasomotor center is the integrative center for a large number of processes which modulate the systemic arterial pressure. The vasomotor center receives these neural inputs, integrates the information, makes a decision, and then coordinates a response through modulation of the autonomic nervous system as described in Systemic Arterial Pressure - Autonomic Control. In most cases, the primary input to the vasomotor center is from the baroreceptors and this is critical for baseline, minute-to-second stability of the systemic arterial pressure in the face of large movements of the body due to day-to-day activity.
- The absence or reduced frequency of baroreceptor impulses informs the vasomotor center that the systemic arterial pressure is too low whereas high baroreceptor impulse frequency informs the center that pressure is too high. The Vasomotor Center then modulates the autonomic nervous system as described in Systemic Arterial Pressure - Autonomic Control to return blood pressure to its set point around 100 mm Hg. In special scenarios such as fear or elation, the vasomotor center may tolerate excessive baroreceptor firing to maintain elevated systemic arterial pressure possibly in anticipation of a burst of physical activity. Such over-riding of the baroreceptors likely occurs due to inputs from higher-order centers which are activated during intense emotional scenarios.