The process of preventing micturition in spite of initiation of the reflex involves
A) the cerebral cortex
B) voluntary stimulation of the motor neuron supplying the external urethral sphincter
C) voluntary stimulation of the internal urethral sphincter via its parasympathetic nerve supply
D) the cerebral cortex and voluntary stimulation of the motor neuron supplying the external urethral sphincter
E) all of these

Question

Quizplus · Accepted Answer

The process of preventing micturition (urination) despite the initiation of the reflex involves the cerebral cortex and voluntary stimulation of the motor neuron supplying the external urethral sphincter. The cerebral cortex can exert voluntary control over the external urethral sphincter through the cortical-spinal motor pathway. This allows us to delay or prevent urination even when the reflex has been initiated. The internal urethral sphincter is controlled involuntarily by the smooth muscles of the bladder neck, and therefore, voluntary control of this sphincter is not possible. Therefore, choices A, B, C, and E are incorrect.

The Process of Preventing Micturition in Spite of Initiation of the Reflex