Editing Male Pelvis (section)

== Pelvic Innervation ==
'''Somatic nerves of the lower abdomen and pelvis'''
{| class="wikitable"
|'''<span style="color:#ff0000">Nerve'''
|'''<span style="color:#ff0000">Origin'''
|'''<span style="color:#ff0000">Motor'''
|'''<span style="color:#ff0000">Sensory'''
|-
|Iliohypogastric
|L1
|Internal oblique and transversus muscles
|Lower anterior abdominal wall
|-
|'''<span style="color:#ff0000">Ilioinguinal'''
|'''<span style="color:#ff0000">L1'''
| 
|'''<span style="color:#ff0000">Anterior scrotum</span>''' (or mons pubis and labium majus)''', root of penis, and upper medial thigh'''
|-
|'''<span style="color:#ff0000">Genitofemoral'''
|'''<span style="color:#ff0000">L1, L2'''
|'''<span style="color:#ff0000">Genital branch: cremaster muscle'''
|'''<span style="color:#ff0000">Genital branch: anterior scrotum</span>''' (or mons pubis and labium majus)

'''<span style="color:#ff0000">Femoral branch: upper anterior thigh'''
|-
|'''Lateral femoral cutaneous nerve of thigh'''
|'''L2, L3'''
| 
|'''Sensory to anterior and lateral thigh'''
|-
|'''<span style="color:#ff0000">Femoral'''
|'''<span style="color:#ff0000">L2, L3, L4'''
|'''<span style="color:#ff0000">Extensors of the knee'''
|'''<span style="color:#ff0000">Anterior thigh and medial leg'''
|-
|'''<span style="color:#ff0000">Obturator'''
|'''<span style="color:#ff0000">L2, L3, L4'''
|'''<span style="color:#ff0000">ADDuctors of the thigh'''
|'''<span style="color:#ff0000">Medial thigh'''
|-
|Lumbosacral trunk
|L4, L5
| colspan="2" |Joins the sacral nerves to form the lumbosacral plexus that supplies motor and

sensory innervation to the lower extremities
|-
|Posterior femoral cutaneous
|S2, S3
|
|Perineum, posterior scrotum, and posterior thigh
|-
|'''Pudendal'''
|'''S2, S3, S4'''
|'''Levator ani, muscles of the urogenital diaphragm, anal and striated urethral sphincter'''
|'''Perineum, scrotum, penis'''
|-
|'''Pelvic somatic efferents'''
|'''S2, S3, S4'''
|'''Motor supply to levator ani and striated urethral sphincter'''
| 
|-
|'''Nervi erigentes'''
|'''S2, S3, S4'''
|'''Parasympathetic fibers from the sacral cord that supply the pelvic viscera'''
| 
|}

* '''Lumbosacral plexus'''
** '''The ilioinguinal and iliohypogastric nerves''' run laterally over the anterior aspect of the quadratus lumborum and '''travel through the transversus abdominis to run deep to the internal oblique muscle'''
*** '''The ilioinguinal nerve (L1) passes through the internal oblique muscle to enter the inguinal canal laterally. This nerve travels outside and anterior to the cord.  Can be damaged during orchiectomy'''
** '''Genitofemoral nerve (L1, L2)'''
*** '''Courses anterior and parallel to the psoas muscle and pierces the psoas muscle''' to reach its anterior surface in the retroperitoneum and then travels to the pelvis
*** '''May be injured during a psoas hitch procedure (suture placement) and laparoscopic varicocelectomy (ligation).'''
*** '''The nerve typically divides into genital and femoral branches near the level of the inguinal ligament.'''
**** '''The genital branch travels IN the spermatic cord through the inguinal canal.'''
**** The femoral branch passes under the inguinal ligament and enters the femoral sheath.
** '''Lateral femoral cutaneous nerve of thigh'''
*** Lateral to psoas muscle in iliacus fascia
** '''Femoral nerve (L2, L3, L4)'''
*** '''Travels within the psoas muscle''' for most of its pelvic course and then exits its lateral side to pass under the inguinal ligament.
*** '''During a psoas hitch, sutures should be placed in the direction of the nerve (and the psoas muscle fibers) to avoid nerve damage or entrapment.'''
*** '''Compression of the femoral nerve may occur intraoperatively with placement of retractor blades on the psoas muscle or inferolaterally against the inguinal ligament'''
*** '''A stretch injury to the femoral nerve may occur with prolonged hip flexion in low lithotomy position used during minimally invasive pelvic surgery'''
** '''Obturator nerve (L2, L3, L4)'''
*** Emerges in the true pelvis from beneath the psoas muscle, lateral to the internal iliac vessels, and passes through the obturator fossa to the obturator canal. In the fossa, it is '''lateral and superior to the obturator vessels''' and is surrounded by the obturator and internal iliac lymph nodes.
*** Electrocautery employed during a transurethral resection of bladder tumor (TURBT) procedure may result in obturator nerve stimulation with subsequent rapid, forceful hip adduction. If this potential event is not anticipated and accounted for, severe bladder perforation may occur
** '''An exaggerated lithotomy position may stretch the lumbosacral nerve (L4, L5) or place pressure on its peroneal branch (L4-S2, terminal branch of sciatic nerve) at the fibular head to produce foot drop.'''
** '''The sacral plexus''' lies on pelvic surface of piriformis deep to endopelvic fascia & posterior to internal iliac vessels
** '''Pelvic and perineal branches of the sacral plexus include (4):'''
**# The posterior femoral cutaneous nerve (S2, S3)
**# '''The pudendal nerve (S2, S3, S4)'''
**# The nervi erigentes (S2, S3, S4) to the autonomic plexus
**# Pelvic somatic efferent nerves from the ventral rami of S2, S3, and S4, which travel on the pelvic surface of the levator ani in close association with the rectum and prostate and are separated from the pelvic autonomic plexus by the endopelvic fascia.
*** '''Pudendal nerve'''
**** '''Follows the internal pudendal artery to the perineum'''
**** '''Branches (3):'''
****# '''Dorsal nerve of penis/clitoris (first branch)'''
****# '''Inferior rectal nerve'''
****# '''Perineal nerve'''
* '''Autonomic Innervation'''
** '''Pelvic/Inferior hypogastric plexus'''
*** '''The presynaptic sympathetic cell bodies reach the pelvic plexus by 2 pathways:'''
***# '''Superior hypogastric plexus'''
***#* '''Cell bodies in the lateral column of gray matter from T10-L2 which project to the pelvic autonomic plexus [via the hypogastric nerve]'''
***# '''Pelvic continuation of the sympathetic trunks'''
***** '''Branches from the sacral sympathetic ganglia'''
*** '''Pre-synaptic parasympathetic innervation arises from the intermediolateral cell column of the S2-4 (pelvic splanchnic nerves/nervi erigentes) sacral cord'''
*** Rectangular, ≈4-5 cm long, and its '''midpoint is at the tips of the seminal vesicles'''.
*** Oriented in the sagittal plane on either side of the rectum
*** '''Pierced by the numerous vessels''' going to and from the rectum, bladder, seminal vesicles, and prostate.
**** '''Clinical significance: Division of the so-called lateral pedicles of the bladder and prostate proximally not only interrupts the vessels but also transects the nerve supply to the prostate, urethra, and corpora cavernosa with attendant postoperative impotence. Ligation is best carried out near the bladder to avoid nerve damage.'''
*** During radical prostatectomy, the nerves are most vulnerable at the apex of the prostate, where they closely approach the prostatic capsule at the 5 and 7 o’clock positions.