During the micturition reflex
A)GFR is increased due to constriction of the efferent arteriole
B)there is increased activity of the parasympathetic motor neurons that control the smooth muscle of the bladder . C)stimulation of stretch receptors in the bladder wall result in afferent impulses arriving in the lumbar region of the spinal cord
D)the external sphincter relaxes as the result of a parasympathetic reflex.
E)the internal sphincter must be consciously relaxed.
B) there is increased activity of the parasympathetic motor neurons that control the smooth muscle of the bladder.
During the micturition reflex:
A) GFR (glomerular filtration rate) is not directly affected. The micturition reflex primarily involves the urinary bladder and urethra, not the kidneys.
B) There is increased activity of the parasympathetic motor neurons that control the smooth muscle of the bladder. This is correct. The parasympathetic nervous system promotes bladder contraction and micturition.
C) Stimulation of stretch receptors in the bladder wall results in afferent impulses arriving in the lumbar region of the spinal cord. This is also correct. When the bladder becomes distended, stretch receptors are activated and send signals to the spinal cord.
D) The external sphincter relaxes as a result of a parasympathetic reflex. This is incorrect. The external sphincter, which is under voluntary control, needs to be consciously relaxed during the micturition reflex.
E) The internal sphincter does not need to be consciously relaxed. The internal urethral sphincter is mainly under involuntary control, and relaxes automatically during the micturition reflex. It is regulated by the autonomic nervous system, not conscious control.
Therefore, the correct answers are:
B) There is increased activity of the parasympathetic motor neurons that control the smooth muscle of the bladder.
C) Stimulation of stretch receptors in the bladder wall results in afferent impulses arriving in the lumbar region of the spinal cord.