pelvic innervation and lumbo-sacral trunk

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2. PELVIC
INNERVATION
BY:
SALAMAT ALI
ROLL NO: 26
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3. Introduction
 The pelvis is mainly innervated by;
1. Sacral plexus
2. Coccygeal plexus
 Bed of these plexuses is formed by;
1. Piriformis muscle
2. Coccygeus muscles
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4. LUMBOSACRAL TRUNK
 L4 unite with anterior ramus of L5 nerve to form
LUMBOSACRAL TRUNK
 Thick cord like structure
 Joins to form sacral plexus
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6. Sacral Plexus
 L4-S4:
 Superior gluteal nerve (L4-S1):
To gluteus medius and minimus.
 Inferior gluteal nerve (L5-S2):
To gluteus maximus.
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8. Sacral Plexus
Muscular branches:
Quadratus femoris (L4-S1).
Obturator internus (L5-S2).
Piriformis (S1-2).
Levator ani and coccygeus (S3-4).
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10. Sacral Plexus
 Posterior femoral cutaneous (S1-S3):
To buttock and uppermost region of posterior
thigh.
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11. Sacral Plexus
 Pudendal (S2-4):
To perineum:
Inferior rectal nerve:
Innervates anal canal.
Dorsal nerve of penis.
Perineal nerve:
Posterior scrotal nerve.
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12. Sacral Plexus
 Sciatic nerve (L4-S3):
Passes through greater sciatic foramen.
1. Tibial nerve (L4-S3).
2. Common peroneal nerve (L4-S2).
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13. Coccygeal Plexus
Comprise of two nerves;
1: S4, S5, coccygeal nerve:
 Supplies coccygeus, part of levator ani
muscle & sacrococcygeal joint.
2: Anococcygeal nerve:
 Pierce the coccygeus and anococcygeal
ligament to supply a small area of skin b/w
the tip of the coccyx and the anus.
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15. Lumbar Plexus
 (T12) L1-5.
 Ilioinguinal nerve:
Lateral to psoas major.
Anterior scrotal nerve (male):
To scrotum.
Labial branch (female):
To labia majora.
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17. Lumbar Plexus
 Genitofemoral nerve (L1-2):
Anterior to psoas major.
Genital branch:
To scrotum (male).
To labia majora (female).
 Lumbosacral trunk (L4-5).
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19. Sympathetic System
 Lumbar splanchnic nerves:
Sympathetic.
From lumbar plexus to:
Abdominal sympathetic plexus.
Inferior mesenteric ganglion.
Superior hypogastric plexus:
To uterine tubes in female.
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20. Sympathetic System
 Sacral splanchnic nerves:
Sympathetic.
From sacral plexus.
Feed into sacral sympathetic trunk and then
into inferior hypogastric plexus.
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21. Sympathetic System
 Sacral sympathetic trunk:
Paravertebral ganglia.
Ganglion impar:
Coccygeal ganglion.
Superior hypogastric:
Sympathetic.
From lumbar and sacral splanchnic
nerves.
Feed into inferior hypogastric plexus.
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22. Sympathetic System
 Sacral sympathetic trunk:
Paravertebral ganglia.
Inferior hypogastric plexus:
Mixed parasympathetic.
In males innervates urethra, ductus
deferens, prostate gland, and ejaculatory ducts.
In females, innervates urethra and produces
uterovaginal plexus.
Produces vesicle plexus (urinary bladder).
Supplies rectum.
Uterovaginal plexus (uterus, vagina, ovaries.
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24. Parasympathetic System
 Pelvic splanchnic nerves
Parasympathetic.
S2-4.
Feed into inferior hypogastric plexus.
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25. Parasympathetic System
 Inferior hypogastric plexus:
In females:
Innervates:
Urethra.
Rectum.
Produces:
Uterovaginal plexus (uterus, vagina,
ovaries).
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26. Injury to pelvic nerves
 During childbirth; fetal head may compress the
nerves of mother’s sacral plexus
Produce lower limb pain
 Obturator nerve is vulnerable to injury during
surgery.
Injury of this nerve cause;
1. Painful spasm of adductor muscles of thigh.
2. And sensory deficits in the medial thigh region.
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