baroreceptors
Last reviewed 01/2018
Baroreceptors are specially adapted groups of nerve fibres within the walls of the:
- carotid sinus, a dilatation of the internal carotid artery
- aortic arch
- great vessels
- heart
They are stretch receptors. They send signals to the central nervous system in proportion to the mean blood pressure and the rate of change of blood pressure within the respective vessel. The carotid sinus sends its afferent signals within the glossopharyngeal nerve to the nucleus ambiguus. The aortic arch sends its signals in the vagus nerve to the nucleus of tractus solitarius.
The rate of firing of the nerve potentials begins to rise above 60-70mmHg. The maximum rate of firing of action potentials occurs at 170mmHg.
The central connections of the medullary centres are part of a cardiovascular circuit that regulates heart rate, contraction and peripheral resistance for close control of blood pressure.