Explain the roles of baroreceptors and chemoreceptors in homeostasis.

Explanation:

The circulatory system plays an extremely important role in maintaining the homeostasis of the internal environment as it should provide to all cells of the body the ideal conditions for their metabolism, ensuring adequate nutrient and oxygen metabolic effects of all body tissues. To perform this function, the cardiovascular system is equipped with afferent sensory systems that inform the central nervous system on the general state of circulation. Among the afferent systems that act in the short term control of blood pressure (BP), the most studied are arterial baroreceptors and peripheral chemoreceptors.

In situations of elevated blood pressure, arterial baroreceptors (inserted into the aorta and carotid vascular walls) depolarize and the action potentials are transmitted to the central nervous system (CNS) through their afferences. After processing this information in the CNS, sympathetic and parasympathetic autonomic adjustments are promoted to normalize blood pressure and adequate levels for perfusion of different organs and tissues.

The chemoreceptor reflex acts in the same way as the baroreflex. However, it is stimulated by cells that are sensitive to oxygen deficiency and excess of carbon dioxide. When blood pressure drops, receptors are stimulated by the increase of CO2 and decrease of O2; transmitted signals reach the vasomotor centers exciting them, leading to effects similar to those caused by the activation of the baroreflex.