Nervous control of urination involves what mechanism(s)?
A) The brain determines the need for urination from an internal clock.
B) Stretch receptors in the urinary bladder send impulses directly to the sphincters to cause urination.
C) Stretch receptors in the urinary bladder send impulses to the spine, causing a urinary reflex, but the brain can delay the reflex.
D) Stretch receptors in the urinary bladder directly send impulses to the brain that consciously decides to stimulate sphincters to relax.
E) Chemical receptors in the bladder detect urine concentration and trigger a reflex action.

Question

Quizplus · Accepted Answer

Stretch receptors in the urinary bladder send impulses to the spinal cord, causing the spinal reflex that initiates urination. The brain can delay this reflex voluntarily by inhibiting the spinal reflex. This allows for conscious control over urination. Option A is incorrect because the need for urination is generally determined by bladder stretch, not an internal clock. Option B is incorrect because the stretch receptors do not directly cause urination – it is the spinal reflex that causes the bladder to contract and sphincters to relax. Option D is incorrect because the brain does not receive direct input from stretch receptors in the bladder, and urination is not generally a consciously controlled process. Option E is incorrect because chemical receptors in the bladder are not the primary mechanism that triggers urination.

Nervous Control of Urination Involves What Mechanism(s)