it's Origin, Motor and Sensory innervation.

2. Presented To
Semester II

3. Lumbar Spinal nerves  Lumbar plexus
Sacral spinal nerves  Sacral plexus
Together form the Lumbosacral plexus
• Lumbar plexus is the upper portion.
• Sacral plexus is the lower portion.
Lumbosacral Plexus
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4. Lumbar plexus
Larger part of
It is formed by first four lumbar nerves
Ventral rami of the L4 pass communicating with
L5 to form
lumbar plexus pass in front of the hip joint.
It provides motor and sensory contributions to
the anterior and medial compartment of leg as
well as abdominal wall and the pelvis areas.
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5. • Runs posterior to the Psoas major lateral border.
• Anterior to Quadratus Lumborum.
• it pierces the Transversus abdominis to run above
the iliac crest.
• It gives motor branches to these muscles.(discuss
above)
• Sensory branch to the skin of the lateral hip.
• anterior cutaneous branch Hypogastric region
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6. • Follows a course slightly
inferior to iliohypogastric
nerve , With it may
Anastomose, and is distributed
to the skin of the upper medial
part of the thigh and the root
of the penis and scrotum
(mons pubis and labia majora)
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7. Genitofemoral nerve (L1,L2)
• Emerges from the anterior surfaces of
the psoas muscles, runs obliquely
downward on the surface of this
muscle and divides into the external
spermatic nerve , which supplies the
cresmastric muscle and the skin of the
scrotum or labia and the
lumboinguinal nerve, which supplies
the skin of the middle upper part of
the thigh.
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8. Lateral femoral cutaneous nerve (L2,L3)
•Passes obliquely across the
iliacus muscle and under
Inguinal ligament to divide into
several rami distributed to the
skin of the anterolateral side of
the thigh.
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9. Femoral Nerve (L2-L4)
Largest branch of the lumbar plexus.
Arise from the posterior division of the plexus which derived from L2,L3,L4.
Emerges from the lateral border of the psoas muscle just above the inguinal
ligament where it divides into terminal branches.
Motor branch above the inguinal ligament supply the iliopsoas.
Motor branches in the thigh supply the Sartorius, pectineus and quadriceps
femoris muscles.
Sensory branches include anterior femoral cutaneous branches to the
anterior and medial surface of the thigh and the saphenous nerve to the
medial side if the leg and foot.
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11. Obturator Nerve (L2-L4)
Arise from the anterior division of L2,L3,L4.
Emerges from the medial border of the
psoas muscle near the brim of the pelvis.
passes on the lateral side of the
Hypogastric vessels and Ureter and
descends through the obturator canal in
the upper part of the obturator foramen to
the medial side of the thigh.
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12. In the canal the obturator nerve splits into
anterior and posterior branch.
Motor rami from the posterior branch
supply the obturator externus and adductor
magnus muscles.
Motor rami from the anterior branch supply
the adductor longus , adductor brevis and
gracilis muscles.
Sensory rami from the anterior branch of
the nerve supply the hip joint and a small
area of skin on the medial internal part of
the thigh.
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14. Sacral plexus
Roots Anterior rami of L4-L5 and S1-S4.
Each of the 5 roots splits inti an anterior
and posterior divisions
The upper 4 posterior divisions (L4,L5 and
S1,S2) join to form the common peroneal
nerve.
All 5 of the anterior divisions (L4,L5 and
S1,S2,S3) join to form the Tibial nerve.
The peroneal and tibial nerves are fused
as the sciatic nerve.
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15. Pudendal nerve (S2-S4)
Roots anterior division of
S2,S3 and S4.
Main nerve of perineum.
Carry sensation from
external genitalia (both sex)
as well give motor
innervation to various pelvic
floor muscles.
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16. Sciatic Nerve
Sciatic nerve is the largest nerve in the body.
It consists of 2 separate nerves in one sheath;
Common peroneal
Tibial Nerve
The common peroneal nerve is formed by the
upper 4 posterior divisions of the sacral plexus.
The Tibial nerve is formed from all 5 anterior divisions
of the sacral plexus.
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17. The Nerve leaves the pelvis through the
greater Sciatic foramen and terminates
in the thigh by dividing into the Tibial
and Common peroneal nerves.
Branches in the thigh supply the
Hamstring muscles; Rami from the Tibial
trunk pass to the Semitendinosus and
Semimembranous muscles, the long
head of the biceps, and the adductor
magnus muscles ; and a Ramus from the
Common peroneal trunk supplies the
short head of the biceps.
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18. Common peroneal nerve (L4,L5and S1,S2)
Formed by the fusion of the upper 4 posterior
divisions of the sacral plexus (L4-S2)
upper part of the popliteal space, where the
common peroneal nerve begins its independent
course.
Sensory branches  Superior and inferior
articular branches to the knee joint and the
lateral sural cutaneous nerve, which joins the medial
sural Cutaneous nerve (from the Tibial nerve) to form
the sural nerve Supplying the skin of the lower dorsal
aspect of the leg. The lateral malleolus and lateral side
of the foot and fifth (5) toe.
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19. Further divide into superficial and deep
peroneal nerves.
Accompanies with the anterior Tibial recurrent
artery supplying the Tibiofibular and knee joint a
small branch to tibialis anterior muscle.
The superficial peroneal nerve descends along
the intermuscular septum to supply muscular
branches to the lateral of the leg, and terminal
cutaneous branches to the Dorsum of the foot,
part of Big toe, and 2nd and 5th toes up to the 2nd
phalanges.
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20. The Deep peroneal (anterior Tibial) nerve
descends in the anterior compartment of the
leg.
Muscular branches extend to the Tibialis
anterior, Extensor digitorum longus , Extensor
hallucis longus and Peroneus tertius muscles.
Articular filaments supply the inferior
tibiofibular and ankle joint.
Terminal branches extend to the skin of the
adjacent sides of the first 2 toes and the
Extensor digitorum brevis muscles and
Adjacent joints.
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21. Tibial Nerve (L4,L5 and S1,S2,S3 )
Roots; Anterior divisions of L4,L5 and S1-S3.
The Tibial nerve is the largest component of
the Sciatic nerve in the thigh.
It courses to the dorsomedial aspect of
ankle, from which point its terminal
branches, the Medial and Lateral planter
nerves, continue into the foot.
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22. Motor branches extend to the
Gastrocnemius, plantaris, soleus,
popliteus, Tibialis posterior, flexor
digitorum longus pedis, and flexor
halluces longus muscles.
Sensory branches The medial sural
cutaneous nerve, joins the lateral sural
nerve to form the sural nerve, which
is the skin of the dorsolateral part of
the leg and the lateral side of the foot.
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23. Medial planter nerve
Motor branches to the flexor
digitorum brevis, adductor
halluces, flexor halluces brevis,
and 1st Lumbrical muscles .
Sensory branches to the
medial side of the sole, the
planter surface of the medial 3
and half toes.
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24. lateral plantar nerve
Motor branches to all the small
muscles of the sole except those
innervated by the medial plantar
nerve .
Sensory branches to the lateral
1st and half Toes.
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