Download Sacral plexus and nerves of pelvis

Nerves of Pelvis and Perineum + Sacral Plexus.
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Pelvic nerves
Sacral plexus
Coccygeal plexus
Pelvic hypogastric plexus
Lumbosacral trunk:
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At pelvic brim formed by
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Posterior ramus of L4
Anterior ramus of L5
Passes anteriorly on the ala of sacrum and join the sacral
plexus
Sacral plexus
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Broad triangular structure
Formed by :
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L4 (anterior div.),L5,S1,S2,S3,S4
Location
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Posterolateral wall of lesser pelvis
Lateral to anterior sacral foramina
Relations of sacral plexus
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Anterior
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Lateral sacral arteries and veins
Ureter
Parietal pelvic fascia
Posterior
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Piriformis
Superior gluteal artery and inferior gluteal artery
pass up and below S1
Branches of sacral plexus
Sciatic nerve (L4-S3)
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Largest nerve of body
Converge on anterior surface of piriformis
Enter greater sciatic foramen and pass out of pelvis
Supply posterior aspect of thigh and entire leg and foot
Pudendal nerve (S2,S3,S4)
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Main nerve of perineum
Chief nerve of external genitalia
Leaves pelvis thru Greater sciatic foramen below piriformis
and sacrospinous ligament
Enters perineum thru lesser sciatic foramen
Superior gluteal nerve
(L4,S1,S2)
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Passes out of pelvis through greater sciatic foramen
Inferior gluteal nerve (L5,S1,S2)
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Leaves out through greater sciatic foramen
Below piriformis
Superficial to sciatic and inferior gluteal artery
Supplies gluteus maximus
Nerve to Piriformis(S1,S2)
Perforating cutaneous nerve(S2,S3)
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Pierces the sacrotuberous ligament
Supply skin of buttock
Posterior femoral cutaneous nerve (S1,S2,S3)
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Passes backward below piriformis behind sciatic nerve
enter gluteal region
Nerve to quadratus femoris and inferior gemellus
(L4,L5,S1)
Leaves pelvis in front of sciatic nerve
Nerve to obturator internus and superior gemellus
(L5,S1,S2)
Leaves pelvis lateral to pudendal vessels below piriformis
Nerve to levator ani and coccygeus (S3,S4)
Pelvic splanchnic nerves
(parasympathetic)
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S2, S3, S4.
S3 contributes the most in making the pelvic
nerves
Pass into the inferior hypogastric plexus and
mix with sympathetic nerves to supply pelvic viscera.
Distal colon
Coccygeal plexus:
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Small network of nerve fibres
Formed by
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S4,S5,Coccygeal nerves.
Location
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Pelvic surface of coccygeus and levator ani
Supplies
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Coccygeus
Levator ani
Sacrococcygeal joint
Annococcygeal branch
Pelvic autonomic nerves
Sacral sympathetic trunks
Periarterial plexus
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Ovarian
Superior rectal
Internal iliac arteries
Hypogastric plexuses
Pelvic splanchnic nerves
Sacral sympathetic trunk
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Smaller than lumbar
Has 4 ganglia
Descends on pelvic surface of sacrum on medial margin of anterior
sacral foramen
Converge in front of coccyx forming ganglia impar
Posterior to rectum
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Send branches to
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Median sacral artery
Inferior hypogastric plexus
Hypogastric plexus
Superior hypogastric plexus
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Inferior to bifurcation of aorta
Right and left hypogastric plexus
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Descends on anterior surface of sacrum
Lateral to rectum
Inferior hypogastric plexus
Inferior hypogastric plexus
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5cm anteroposteriorly
2cm vertically
Location
In male
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Lateral to rectum
Inferolateral to bladder
Prostate and seminal glands
In female
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Cervix and lateral fornices of vagina
Inferior hypogastric plexus
Contributions to the plexus include:
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Continuation of the hypogastric plexus on either side, in the form of the hypogastric nerve.
Sacral splanchnic nerves, which emerge from the sympathetic trunk.
Pelvic splanchnic nerves (S2, S3, S4) parasympathetic efferent fibers to the plexus.
Functions
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Sympathetic inhibits rectal peristalsis
Stimulates contraction of internal genital organs producing ejaculation
Parasympathetic stimulates contraction of rectum and bladder.
Causes erection.
Injury to pelvic nerves
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During childbirth mother’s sacral plexus is compressed producing pain
Obturator nerve is vulnerable to injury during surgery of removal of
cancerous lymph nodes from lateral pelvic wall
Obturator nerve (L2-L4)
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Branch of lumbar plexus
Arises in abdomen comes down to pelvis and enter the obturator canal
Lie highest in obturator foramen
Divides into anterior and posterior parts
Supply medial thigh muscle
Gives no branch in pelvis