Traube Hering waves are due to?

Ans. (a) Fluctuation in BP with respirationRef.:Textbook of medical physiology 2nd ed. / 435Traube Hering Waves are oscillations in BP that occur with a frequency of 4/min, and are attributable to rhythmic oscillations in intensity of sympathetic vasomotor discharge.TRAUBE-HERING WAVESThese are the medium waves of the recording, which are formed by fluctuation in BP synchronous with respiration. The wave shows a rise in pressure during inspiration and a fall during expiration. These waves are produced due to change in vagal and sympathetic activity in different phases of respiration. The vasomotor centre is stimulated during inspiration by the irradiation of impulses from the inspiratory centres which causes rise in blood pressure. Also during inspiration, the intrathoracic pressure becomes more negative, therefore venous return increases, which in turn increases cardiac output and BP.Also Know* Traube semilunar space: a crescentic space about 12 cm wide, just above the costal margin.* Traube sign: a double sound or murmur heard in auscultation over arteries in significant aortic regurgitation.