Afferent fiber for blood pressure control goes to?
Ans. (c) NTSRef: Ganongs Review of Medical Physiology 25th Ed; Page No- 588Baroreflex* It is mediated by sensors which are the stretch receptors known as baroreceptors. They are# Carotid sinus: A small dilation in internal carotid artery# Aortic arch: In the aortic arch wall* These receptors are spray-type myelinated nerve endings located in the adventitia of these blood vessels.* They respond to change in mean arterial pressure (MAP).Innervation of Baroreceptors:* Carotid sinus is innervated by the branch of glossopharyngeal nerve called "carotid sinus nerve". It is also called as "Hering s nerve".* Aortic arch is innervated by branch of the vagus nerve called 'aortic depressor nerve". It is also called 'Cyons nerve".* Nerves that baroreceptors are collectively called "Buffer nerves" because they neutralize change in BP.Understating the Baroreflex* "Whenever blood pressure increases, baroreceptors increase their discharge and send their impulse to medulla which ultimately decreases the blood pressure".* Baroreflex is classic example of negative feedback mechanism.* Even at rest, baroreceptors fire at low level. They increase their firing whenever BP increases and decrease their firing whenever BP decreases.* Baroreceptors ultimately rely upon medulla for control of BP.
Nucleus ambiguous
Rostral-ventro lateral medulla
NTS
Caudal-ventral lateral medulla
Nervous System