PERIODIC MICTURITION IN THE CAT AFTER SECTION OF THE SACRAL NERVES

Abstract

The motor and sensory sacral nerve roots were cut in cats, first upon one side and afterwards also on the other side. Graphic records of vesical activity were obtained from the normal animals and at suitable periods after the operations. There was a slight increase in vesical volume in the first few days after section of the roots unilaterally. The volume then returned to normal or slightly less than normal. A greater enlargement of the bladder followed section of all the sacral roots. Later automatic micturition became established; its efficiency varied in different cases. The time of onset and the efficiency of micturition were related to the development of rhythmical contraction waves in the vesical muscle and to a lowering of the intravesical pressure at the time fluid escaped from the urethra. The contraction waves showed no summation; they were increased in amplitude in response to stretch stimuli. With the onset of periodic micturition, the volume of the bladder was decreased to less than normal.