Re: Questions for the Pelvic Nerves and Vessels

Comments:
: : : Questions for the Pelvic Nerves and Vessels : : : These questions were not submitted by the lecturer. : : : True/False - September 12, 2011 : : : Visceral afferent fibers that connect to the cell bodies of pelvic splanchnic nerves are part of the autonomic nervous system. : : F - by definition, autonomic is a motor system. No visceral afferent fibers allowed... : Agree. : : : A transection of the spinal cord superior to the S2 cord level preserves spinal reflexes of micturition. : : T : Agree. : : : Spinal cord levels S2-4 elaborate somatic and autonomic nerves that act together to mediate micturition, defecation, and ejaculation. : : T : Agree. : : : Like the sympathetic nerves of the coronary arteries, the sympathetic nerves of the perineum dilate the helicine arteries. : : F - the parasympathetic pelvic splanchnic nerves (nervi erigenti) dilate the helicene arteries. The sympathetic (lumbar splanchnic?) innervation contributes to helicene artery constriction. : Agree. : : : Similar to peristalsis along the alimentary canal, parasympathetic nerves of the perineum control peristalsis of the seminal vesicles and ejaculatory ducts. : : F - sympathetic control peristalsis of seminal vesicles and ejaculatory ducts. Lumbar splanchnic or other nerves? : Agree. : : : Lumbar splanchnic nerves and pelvic splanchnic nerves are sources of sympathetic supply to the pelvic plexus. : : F - pelvic splanchnics are parasympathetic : Agree. : : : The right and left hypogastric nerves convey visceral afferent fibers from the uterus and sympathetic supply to the Uterus. : : T? : Agree. : : : Lesioning of the hypogastric nerves to disrupt visceral afferent fibers as a treatment for intractable pain removes all sympathetic supply to the uterus. : : F - still some input from lumbar and sacral splanchnics? : Agree. Not all of the aortic plexus extends to the superior hypogastric plexus. Some of the aortic plexus extends to the common and internal iliac plexuses. : : : Despite lesioning of the hypogastric nerves, there are at least two other pathways that convey sympathetic fibers to the uterus. : : See above... : Agree. The internal iliac plexus, the sacral sympathetic trunk, and the superior rectal plexus. Plus, possibly more. : : : Sacral splanchnic nerves are postganglionic and pelvic splanchnic nerves are preganglionic. : : T : False. Sacral splanchnic nerves are preganglionic. They synapse in unnamed microganglia of the inferior hypogastric plexus. : : : The cavernous nerves are part of the prostatic autonomic plexus. : : T : Agree. : : : The cavernous nerves are a continuation of fibers from the sacral splanchnic nerves. : : F - parasympathetic pelvic splanchnic nerves : Agree. : : : The sympathetic supply to the descending colon is by an arterial plexus and the parasympathetic supply is by a retroperitoneal path along the medial margin of the descending colon. : : T : Agree. : : : The external anal sphincter is a somatic muscle innervated by the inferior rectal branches of the pudendal nerve. : : T : Agree. : : : Disruption of the pelvic splanchnic nerves is expected to cause impotence. : : T : Agree. : : : The pudendal nerve typically elaborates the inferior rectal nerve immediately proximal to the entrance of the pudendal canal. : : T - or while within canal : Agree. : : : The falciform edge is on the medial margin of the ischio tuberosity and contributes a bony wall of the pudendal canal. : : T : Agree. : : : The distal opening of the pudendal canal is at the inferior edge of the urogenital diaphragm. : : T? : Agree. Maybe a bit posterior from the posterior free edge. : : : The primary lymphatic drainage of the superior pole of the ovary is to upper lumbar nodes and the inferior pole drainage is to internal iliac and : : superficial inguinal nodes. : : T? : Agree. Know that lymph vessels accompany the ovarian and round ligaments. : : : An infection of the perianal skin may involve superficial inguinal lymph nodes and somatic pain. : : T : Agree. : : : True/False - September2010 : : : Sacral splanchnic nerves and pelvic splanchnic nerves are, in fact, the same nerves. : : F : Agree. : : : Parasympathetic preganglionic cell bodies that mediate contraction of the detrusor muscle are located in the intermediolateral cell column at levels L1-2. : : Cord level or spinal column level? - The level in the spinal column would be right, but the ventral rami of the pelvic splanchnics arise from S2-S4 cord levels. : Agree. False for cord level. : : : Peristalsis of the hindgut is driven by the parasympathetic division of the autonomic nervous system. : : T - by the pelvic splanchnic nerves : Agree. : : : Relaxation of the external anal sphincter and the puborectalis is driven by the somatic nervous system. : : T : Agree. And sphincter urethrae. : : : The helicine arteries dilate in response to parasympathetic activity. : : T : Agree. : : : The bulbospongiosus and the ischiocavernosus muscles contract in response to the somatic nervous system. : : T : Agree. : : : Peristalsis of the vas deferens is driven by sympathetic nerves from the pelvic plexus. : : T : Agree. : : : The cerebral release mechanism for urination is mostly driven by the somatic nervous system. : : T? - The general visceral afferent fibers sending inputs to the CNS are somatic, and control over the sphincter urethrae is somatic. : Agree. Urine flowing in the membranous and spongy urethra provides somatic sensation that contributes to a positive feedback loop that is part of the cerebral release mechanism. : : : Both the true urethral sphincter and the function urethral sphincter (uvula) are driven by the somatic nervous system. : : F - internal is driven by autonomic system (parasympathetic) : Agree. But I don't like this question much. Raising levator ani presses the uvula against the anterior prostatic urethra. This constitutes a functional sphincter. Nevertheless, it seems that there are circular fibers in the region that constitute a true sphincter. : : : Sensation from the glans of the penis/clitoris is mediated by the autonomic nervous system. : : F - again with the "it's only a motor system" mantra : Agree. Ommm............ Plus, sensation from the glans is somatic, not visceral. : : : The sacral splanchnic nerves contribute to the inferior hypogastric plexus. : : T : Agree. : : : The pelvic splanchnic nerves contribute to the inferior hypogastric plexus. : : T : Agree. : : : The right and left hypogastric nerves contribute to the inferior hypogastric plexus. : : T : Agree. : : : Gray rami from the sacral sympathetic trunk contribute to the inferior hypogastric plexus. : : T - as an origin for lumbar splanchnic nerves? : False. Lumbar splanchnic nerves travel to the pelvis by way of the hypogastric nerves and the common iliac plexus. Gray rami are contributing sympathetic fibers to the ventral rami that, in turn, make up the sacral somatic plexus (today's lecture highlighted this for the T10 dermatome). Horrendous. These sympathetics fibers may insinuate into the pudendal nerve, then the posterior scrotal nerves, and then innervate dartos fascia of the posterior scrotal. A fly in the ointment. Somatic nerves have autonomic parasites on board. It gets even worse. Buckle up. : : : White rami from the sacral sympathetic trunk contribute to the inferior hypogastric plexus. : : F - there are no white rami "down there" : Agree. Not down there. : : : Nerve fibers derived from the lumbar splanchnic nerves contribute to the inferior hypogastric plexus. : : T : Agree. : : : The uterine autonomic plexus receives contributions from the inferior hypogastric plexus. : : T : Agree. In fact, the uterine autonomic plexus is an extension of the inferior hypogastric plexus. Nevertheless, the aortic plexus may contribute by way of the ovarian autonomic plexus. : : : The uterine autonomic plexus receives contributions from the internal iliac plexus. : : umm...what's the internal iliac plexus? If it's another name for the superior hypogastric plexus, then yes, post-ganglionic sympathetic nerves that came through that plexus to synapse in the inferior hypogastric plexus continue to the uterine plexus. : True. The aortic plexus extends along the common/internal iliac plexuses to the uterine arterial plexus and then to the uterine plexus. The component does not pass through the inferior hypogastric plexus. It simply follows the arteries. Thus, the aortic plexus extends to the uterus by way of the internal iliac arterial plexus and by way of the ovarian arterial plexus. : : : The hypogastric nerves contain both preganglionic and postganglionic sympathetic nerves. (this is true) : True. Fibers derived from sacral splanchnic nerves synapse in microganglia of the inferior hypogastric plexus. : : : The cavernous nerves pass through the urogenital diaphragm to arrive in the perineum. : : T : Agree. : : : Pelvic splanchnic nerves, by way of the inferior hypogastric plexus, contribute to the cavernous nerves. : : T : Agree. Inferior hypogastric plexus to the prostatic autonomic plexus. : : : Surgical resection of the prostate may damage the cavernous nerves. : : T : Agree. : : : Peristalsis at the left colic flexure is indirectly inhibited by lumbar splanchnic nerves. : : T : Agree. Directly inhibited by postganglionic fibers from the inferior mesenteric ganglia. : : : Peristalsis at the left colic flexure is indirectly activated by sacral splanchnic nerves. : : F - by pelvic splanchnic nerves : Agree. Plus, "indirectly" makes the point that the postganglionic cell bodies are intrinsic for the parasympathetic division of the autonomic nervous system. It is the postganglionic fibers that directly have an effect.

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