Which centre first gets the input from neural control of CVS?
(A) RVLM (B) NTS (C) Nucleus ambiguous (D) Raphe Nucleus
(B) Nucleus tractus solitarius - Baroreceptors are spray type nerve endings that lie in the walls of the aeries & are stimulated when stretched. Most abundantly they are found in: 1. Wall of each Internal carotid aery (slightly above the carotid bifurcation) 2. Wall of aoic arch. Signal from the carotid baroreceptor are transmitted through hering's nerve to the glossopharyngeal nerve, in the high neck & then to the NTS in the medulla. Signal from the aoic baroreceptor in the arch of aoa are transmitted through vagus nerve to the same NTS to medulla. RVLM: - Rostral ventral lateral medulla. - Its vasoconstrictor area. - In hypotension, NTS receives the impulse when blood pressure falls & it needs to be increased. | RVLM will be stimulated. The axons of nerve cell bodies of RVLM, ends on each segment b/w T1 & L2. T1 - L2 contain intermediolateral horn, & there are sympathetic nerve cell bodies in them. Nucleus ambiguous: - Has cardio inhibitory area. Raphe nucleus: - Lies in midline of the PONS & medulla. Secrete serotonin. Not related to neural control of CVS