ABSTRACT
Rapid control of blood pressure is accomplished in large part by baroreceptors and the central nervous system reflexes they are part of. Another term for baroreceptor is "pressure receptor" or pressoreceptor. Renin-angiotensin-aldosterone system is involved in slower, longer term control of blood pressure than the neural baroreceptor system, but both act together to maintain steady state blood pressure levels. Chemoreceptor control of the circulation can become important in some abnormalities. Most organs have local metabolic control of blood flow. An increase in organ work and metabolism results in changes in the organ's interstitium that causes arteriolar vasodilatation. Abnormalities in blood pressure control have been demonstrated in patients with heart failure. When compared with normal, the increase in heart rate with upright tilt is blunted. There are multiple levels of control operating simultaneously in the circulation. It is not unusual in biological systems to have multiple control mechanisms acting to maintain an internal steady state.
