1. Baroreceptor reflex: baroreceptors located in the aortic arch and carotid sinus monitor blood pressure. The aortic baroreceptors relay through the vagus nerve; the carotid sinus baroreceptors relay through the glossopharyngeal nerve. Afferent input enters into the tract of the solitary nucleus and can then be sent to cardiovascular control center in the brainstem (vasoconstrictor center, cardiac accelerator center, cardiac decelerator center)
MAP regulation on a beat to beat basis: because the baroreceptors monitor pressure on a beat to beat basis, the baroreceptor reflex is responsible for beat to beat MAP regulation
2. Functional components of cardiovascular control center:
Cardiac accelerator center: works on the SA/AV nodes to increase heart rate and contractility
Cardiac decelerator center: works on the SA/AV nodes to decrease heart rate and contractility
3. Blood pressure and the Renin-Angiotensin system: decreased blood pressure is sensed by renal mechanoreceptors causing juxtaglomerular cells to convert prorenin into renin. Renin then works in the plasma to convert angiotensinogen into angiotensin I, followed by angiotensin I conversion to angiotensin II in the kidneys and lungs.
Angiotensin II: angiotensin II is a powerful vasoconstrictor, stimulates the production of aldosterone, and acts on the renal proximal tubule to increase reabsorption of Na+ and HCO3- 4. Influence on MAP: