Certified Rehabilitation Registered Nurse (CRRN) Practice Exam

The reflex arc associated with micturition is primarily located at which level of the spinal cord?

1. Cervical

2. Thoracic

3. Sacral

4. Lumbar

The correct answer is: Sacral

The reflex arc associated with micturition, which is the process of urination, is primarily located at the sacral level of the spinal cord. This is primarily due to the neural control mechanisms involved in bladder function, which are mediated by the sacral spinal cord segments S2 to S4. At this level, specific neurons and pathways regulate the contraction of the bladder's detrusor muscle and the relaxation of the external urinary sphincter. This coordinated activity allows for the efficient storage and expulsion of urine. Additionally, the sacral region contains the parasympathetic fibers that stimulate bladder contraction when it is full, facilitating the micturition reflex. Understanding the location of this reflex arc is crucial for recognizing how injuries at different levels of the spinal cord can lead to dysfunction in micturition, emphasizing the sacral nerves’ vital role in bladder control. This understanding is fundamental for rehabilitation nursing, as managing urinary function is an important aspect of patient care in various rehabilitation settings.