Anterior rami L1-4 supply psoas and QL segmentally then form plexus in substance of psoas.
Innervates part of lower abdominal wall, but mainly for lower limb
- reinforces sacral plexus (main plexus of lower limb)
L1 ¨ IH an II
L1,2 ¨ GF
L2,3 (posterior divisions) ¨ lat fem cut
L2,3,4 (posterior divisions) ¨ femoral
L2,3,4 (anterior divisions) ¨ obturator
Really segmental body wall nerve and its collateral branch in series with thoracic nerves
¨ skin over inguinal region
¨ motor supply to fibres of internal oblique and transversus roofing the inguinal canal
¨ reach conjoint tendon
Femoral part ¨ skin below middle of inguinal ligament
Genital part ¨ abdominal wall herniated into scrotum for testicular descent (cord)
- sensory to tunica vaginalis and spermatic fasciae
- motor to cremaster; supplies small area of anterior scrotal and labial skin.
Wholly sensory ¨ iliac fascia and peritoneum of iliac fossa
¨ lateral side of thigh to knee
- emerges from lateral border of psoas and enters thigh through / under inguinal ligament
Lateral border of psoas ¨ across iliac fossa b/n psoas and iliacus deep to fascia
¨ supplies iliacus in abdomen
- passes beneath inguinal ligament lateral to femoral sheath, enters femoral triangle
- ¨ pectineus and breaks up into several branches.
N to pectineus ¨ behind sheath to that muscle
N to sartorius ¨ may pierce that muscle and continue as:
Intermediate femoral cutaneous nerve ¨ skin and fascia lata to knee
Medial fem cut nerve ¨ medial side of thigh;
anterior branch reaches front of knee
N to rectus femoris ¨ doubled; branch also ¨ hip jt
N to vastus lateralis: with desc. branch of lat fem circumflex artery b/n rectus fem and vastus int.
N to vastus intermedius ¨ muscle
N to vastus medialis ¨ enters upper subsartorial canal to muscle
- nerves to the three vasti also ¨ knee
Saphenous nerve ¨ in front of femoral
artery in subsartorial canal
¨ infrapatellar branch: pierces sartorius to patella plexus
- then pierces fascia lata b/n sartorius and gracilis ¨ skin and periosteum over subcut tibia
- runs with great saphenous vein in front of medial malleolus ¨ medial foot short of big toe.
From medial psoas on ala on sacrum lateral to lumbosacral trunk
¨ down to side wall of pelvis b/n origin of internal iliac artery and ilium to obturator foramen
¨ supplies parietal peritoneum on pelvic side wall (next to ovary)
Then splits into ant and post divisions:
Anterior ¨ over obturator externus ¨ thigh, hip jt
- runs over adductor brevis deep to pectineus and adductor longus
- supplies these two adductors and maybe pectineus, also gracilis
- cutaneous branch ¨ medial side of thigh
Posterior ¨ obturator externus; pierces its upper border ¨ thigh deep to adductor brevis
- runs on adductor magnus (supplies it)
- ¨ branch with femoral artery to popliteal fossa ¨ knee jt.
Formed from lumbosacral trunk (L4,5) and upper four anterior sacral rami
- the rami divide and unite as they converge on greater sciatic foramen.
S1,2 Straight to muscle
S2,3 Pierces sacrotuberous ligament and glut max there ¨ skin on lower medial buttock
S1,2,3 Below piriformis on sciatic ¨ lower border of glut max ¨ gastroc bellies
¨ strip of deep fascia and skin b/n anterior and posterior axial lines from buttock to midcalf
¨ gluteal branches to buttock
¨ perineal branch around hamstrings & gracilis ¨ lat part of posterior 2/3 of scrotum / labium majora
S2,3,4 PNS outflow; join inferior hypogastric plexus
¨ motor to bladder and colon from splenic flexure down and cause erection
¨ afferents include those for distension, pain from bladder, lower cervix and colon and rectum
¨ referred pain felt in femoral cutaneous nerve distribution
S2,3,4; curls round gluteal surface of sacrospinous lig to pudendal canal ¨ pelvic floor & perineum
¨ inferior rectal nerve arches through ischioanal fossa fat to EAS, canal and perianal skin
¨ perineal nerve terminal branch ¨ forward to skin of posterior 2/3 of scrotum / vulva
- and mucous membrane of urethra and vagina
- motor to perineal muscles (ischiocavernous, bulbospongiosus, superior and deep transverse perinei and sphincter urethrae)
¨ dorsal nerve of penis / clitoris (other terminal branch) pierces perineal membrane below s. pubis.
¨ levator ani and coccygeus (upper surfaces)
B/n levator ani and coccygeus ¨ sin over ischioanal fossa
L4,5,S1 on ischium deep to sciatic ¨ runs deep to obturator internus ¨ deep surface of quadratus fem
- also supplies inferior gemellus and hip jt branch
L5,S1,2; below piriformis, curls around base of ischial spine ¨ obturator internus
- also ¨ superior gemellus
L4,5,S1Passes back though greater sciatic notch above piriformis ¨ plane b/n glut med and minimus
¨ supplies both and ends in tensor fasciae latae
L5,S1,2 Back below piriformis ¨ deep surface of glut maximus
L4,5,S1,S2,S3
Largest branch; actually union of tibial and common peroneal parts
Passes to buttock on post surface of ischium (n. to quadratus femoris deep, post fem cut n. superficial)
- from midway b/n greater trochanter and ischial tuberosity ¨ hamstring compartment
- on obturator internus and gamelli, quadratus femoris then adductor magnus
- overlaid by long head biceps
Main trunk ¨ hamstrings, ischial fibres of adductor magnus
Then divides ¨ tibial and common peroneal nerves
Branches for long head of biceps and two semi muscles are from tibial part, branch to short head biceps from common peroneal part.
Supplies extensor and peroneal compartments of leg and dorsum of foot
Enters apex of popliteal fossa ¨ medial to biceps tendon under deep fascia
¨ crosses plantaris, lat head gastroc ¨ around neck of fibula (injured here) through peroneus longus
¨ divides; in itself supplies no muscles but 3 articular and 2 cutaneous branches:
- articular branches (upper, lower lateral and recurrent genicular) ¨ knee
- sural communicating nerve ¨ sural nerve below gastroc heads to skin
- lat cut nerve of calf ¨ skin and deep fascia over upper half of peroneal compartment
Formed in peroneus longus ¨ deep to EDL ¨ interosseus membrane lateral to vessels
¨ crosses lower end of tibia ¨ dorsum of foot ¨ skin of first cleft
Muscles = extensor compartment; EDL, TA, EHL, peroneus tertius
- and ¨ lateral branch in foot and extensor digitorum brevis
In substance of peroneus longus ¨ in that muscle to anterior border ~1/3 way down leg
- and perforates the fascia to supply skin over peronei and extensor muscles in lower third of leg
Divides to medial and lateral branches to skin and deep fascia on dorsum of foot
- medial branch ¨ medial side of big toe and second cleft
- lateral branch ¨ third and fourth clefts
Calf and sole to toenails; enters apex of popliteal fossa ¨ midline of limb ¨ deep to gastroc heads
¨ across popliteus ¨ runs beneath fibrous arch of soleus
Three genicular nerves: upper and lower medial and middle
Five muscular branches: plantaris, heads of gastroc, soleus, popliteus
One cutaneous: sural nerve ¨ pierces fascia halfway down leg
- joined by peroneal communicating nerve
- runs down beside small saphenous vein behind lateral malleolus ¨ lateral little tow
From fibrous arch nerve runs down with posterior tibial vessels deep to soleus
- neurovascular bundle in groove b/n bellies of FHL and FDL
- Behind medial malleolus (beneath retinaculum) divides:
Four muscular branches: soleus, tib posterior, FH and FDL
Median calcaneal: pierces retinaculum ¨ weight bearing skin of heal.
Medial and lateral plantar nerves ¨ correspond to median and ulnar nerves