The Influence of Sensory Inputs from the Abdomen on Chemoreceptor Activity

Abstract

It is well known that vasomotor activity is regulated by vasomotor centres in the brain stem and in regions above. However, there are also some other important neural mechanisms for the regulation of vasomotor activity in the body that are located in the spinal cord right down to the lumbar segments. An illustration of one such regulatory mechanism aroused by stimulation of receptors in the abdominal viscera is the well-known rise in the arterial blood pressure in paraplegics by distending the bladder, i.e. stimulating the bladder receptors as shown by Guttman and Whitteridge (1). Such effects have been observed in normal human beings, too (2). In addition to the rise in blood pressure, such a stimulation also produces other reflex effects, such as dilation of the pupils, contraction of the somatic muscles in decerebrate or spinal animals, as shown by Downman and McSwiney (3) and in intact and anaesthetized animals with their buffer nerves cut, as shown by Mukherjee (4).