Reflexes of spinal automatism
FROM THE NEUROLOGICAL SECTION OF STATE HOSPITAL, OSLO, NORWAY. PRINCIPALActa Psychiatrica Scandinavica (Impact Factor: 5.61). 08/2007; 1(3):260 - 286. DOI: 10.1111/j.1600-0447.1926.tb11030.x
- [Show abstract] [Hide abstract]
ABSTRACT: The volume threshold for micturition is altered by transection of the brain stem at various levels and also by section of the sympathetic nerves to the bladder. The aim of the present experiments has been to investigate whether the supraspinal influences are brought about by means of changes in peripheral sympathetic mechanisms. Mostly male cats were investigated using the ‘direct cystometry’ method. Cystometrograms obtained preoperatively were compared with those obtained after peripheral sympathectomy and during the phase of increased motility following laparotomy. Then the effects of brain stem transection on the micturition threshold in the presence and absence of sympathetic innervation were compared. The peripheral factor responsible for eliciting the micturition reflex was found to be the tension in the bladder wall as assessed from the intravesical pressure. The lower volume threshold found after sympathectomy is due to the hypertonicity of the bladder following this procedure. The tonic supraspinal influence on the micturition reflex, on the other hand, was not altered by interruption of the sympathetic nerve supply to the bladder. Thus, the expulsion of urine is controlled by two different mechanisms, namely a peripheral regulation of the tension in the bladder wall and a supraspinal regulation of the micturition reflex threshold.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.