innervation of lower limb
TRANSCRIPT
INNERVATION OF LOWER LIMB
MARYAM JAMILAH BINTI ABDUL HAMID082013100002
IMS BANGALORE
OBJECTIVE Able to identify the origin, course and
termination of nerves. Able to annotate the nerves in the
diagram Able to describe muscles supplied by
the nerves
1) LUMBAR PLEXUS
A)ILIOHYPOGASTRIC NERVEOrigin: T12-L1Branch: Lateral and anterior cutaneousbranchesPath: Skin above the pubis Over the lateral side of the buttockModality: Motor and general sensory
B)ILIOINGUINAL NERVEOrigin: T12-L1-Accompanies the spermatic cord through
theinguinal canalBranch: anterior scrotal or labial
branchesPath: skin of scrotum or labia majora adjacent part of thighModality: general sensory.
C)GENITOFEMORAL NERVEOrigin: L1-L2-Accompanies the spermatic cord through
theinguinal canalBranch: genital and femoral branchesPath: skin of scrotum or labia majora cremaster muscle adjacent part of thigh & femoral triangleModality: general sensory and motor.
CI) GENITAL BRANCH passes through the deep inguinal ring
and enters the inguinal canal. In men, the genital branch continues
down and supplies the scrotal skin. In women, the genital branch
accompanies the round ligament of uterus, terminating in the skin of the mons pubis and labia majora
CII) FEMORAL BRANCH The femoral branch passes underneath
the inguinal ligament Travelling adjacent to the external iliac
artery Supplying the skin of the upper, anterior
thigh.
D) LATERAL CUTANEOUS NERVE Origin: L2-L3Branch: Anterior and posterior branchPath/Supply: Anterolateral side of the thigh Anterior part of the gluteal region
DI)ANTERIOR BRANCHBecomes superficial about 10 cm below the inguinalLigament
Divides into branches-supply anterior and lateral parts of the thigh, as far as the knee.
Terminal:Meet anterior cutaneous branches of the femoral nerveand infrapatellar branch of the saphenous nerve toform peripatellar plexus.
DII)POSTERIOR BRANCHOrigin: Lateral cutaneous nerve
Branch: Filaments which pass backward across
the lateral and posterior surfaces of the thigh
-Supply: skin from the level of the greatertrochanter to the middle of the thigh
Path: Pierce into fascia lata
E) FEMORAL NERVEOrigin: L2,L3,L4
Emerges at lateral border of psoas major muscle in abdomen. Passes downwards between psoas major and iliacus muscles. Nerve enters the thigh behind inguinal ligament,lateral to femoral sheath as its formation is behind fascia iliaca.
Modality: general sensory and motor.
Path: enter femoral triangle by passing behind
inguinal ligament In thigh: in the groove between iliacus and
psoas major. NOT in the femoral sheath (located posterior
of the femoral sheath)Branch: Muscular, cutaneous, articular and
vascular
EI) MUSCULARAnterior Posterior
sartorius Rectus femoris, three vasti
(lateralis,intermedius and
medialis) & articularis genu
EII)CUTANEOUSAnterior Posterior
intermediate
Saphenous nervemedial
EIII)ARTICULAR Hip joint (nerve to rectus femoris) Knee joint (nerve to three vasti)
To the femoral artery and its branchesEIV)VASCULAR
F)OBTURATOR NERVEChief nerve of the medial compartment of the thigh
Origin: L2,L3,L4Supply: Adductor muscles of thighDivided into two; anterior and posterior
FI) ANTERIOR DIVISIONSupply:- Pectineus Adductor longus Gracilis Adductor brevis (ocassionally)
FII) POSTERIOR DIVISIONSupply:- Obturator externus Adductor magnus Adductor brevis (ocassionally)
G)ACCESSORY OBTURATOR NERVEOrigin: L3,L4
Descends along the medial border of psoas major, crosses the superior ramus of the pubis behind pectineus.
Termination: divides into 3 branches1) Supply the deep surface of pectineus2) Supply hip joint3) Communicates with the anterior
divison of obturator nerve
2)SACRAL PLEXUS
A) SUPERIOR GLUTEAL NERVEOrigin: L4,L5,S1Course: Enters gluteal region through greater
sciaticnotch above piriformis muscle.Runs between gluteus medius and gluteusminimus to end in tensor fascia lataeBranches: supplies gluteus
medius,gluteusminimus and tensor fasciae latae
B) INFERIOR GLUTEAL NERVE
Origin: L5,S1,S2
Course:
Enters the gluteal region through greater sciatic
notch below piriformis muscle
Branches:
A number of branches to gluteus maximus
muscle only
*Sole supply to the large antigravity, postural muscle with
red fibres,responsible for extending the hip joint
C)SCIATIC NERVE Thickest nerve in the bodyOrigin: (L4,L5,S1,S2,S3)
Tibial part: L4,L5,S1,S2,S3Common peroneal part: L4,L5,S1,S2
Course: Arises in pelvis. Gluteal region:
Passing through greater sciatic foramen below the piriformis to enter the gluteal region
(deep to gluteus maximus muscle.crosses superior gamellus,obturator internus,inferior gamellus,quadratus femoris to enter back of thigh)
Back of thigh Deep to long head of biceps femoris and superficial to
adductor magnusTermination: Divides into two terminal branches at the back
of the thighBranch:
Gluteal
region
Back of thigh;from tibial part From common peroneal part
Muscular
Nil Long head of biceps femoris, semitendinosus,semimembranos
us,ischial part of adductor magnus
Short head of bicep femoris
Articular
Nil Hip joint -
Terminal
Nil Tibial and common peroneal nerves
-
D) TIBIAL NERVEBack of the thighOrigin: L4,L5,S1,S2,S3Course: Long course. First in the popliteal fossa then back of legPopliteal fossa: Nerve descends vertically,superficial to popliteal
vessels.Back of leg:Posterior tibial vessels.superficial to tibialis posterior &deep to flexor digitorum longus. Deep to flexorretinaculum of ankle.
BRANCH:Popliteal fossa Back of leg
Muscular
Medial head of gastrocnemius,lateral head of
gastrocnemius,plantaris,soleus,popliteus
Soleus,flexor digitorum
longus,flexor hallucis
longus,tibialis posterior
Cutaneous &
vascular
Sural nerve Medial calcanean
branches & branch to
posterior tibial artery
Articular
Superior medial genicular,middle genicular,inferior medial genicular
Ankle joint
Terminal
- Medial plantar&lateral plantar nerves
E)COMMON PERONEAL NERVEOrigin: L4,L5,S1,S2-smaller terminal branch of sciatic nerve-back of the thighCourse: Lies in the upper lateral part of popliteal fossa,
along the medial border of biceps femoris muscle.Turns around lateral surface of fibula.Then,lies in the substance of peroneus longus muscleBranches: muscular (short head of biceps femoris),
cutaneous & vascular (lateral cutaneous nerve of calf & sural communicating), articular (superior lateral genicular, inferior lateral genicular, recurrent genicular)
Termination: Superficial peroneal & deep peroneal
EI)SUPERFICIAL PERONEAL Origin: Arises in the substance of peroneus
longus muscle,lateral to the neck of fibulaCourse: Descends in the lateral
compartment of leg deep to peroneus longus.Then lies between peroneus longus and peroneus brevis muscles and lastly between peronei and extensor digitorum longus. Pierce deep fascia in distal 1/3 of leg and descend to the dorsum
Branch: Supplies peroneus longus &peroneus brevis muscle. Cutaneous branch.
EII)DEEP PERONEAL Entire compartment of the leg & dorsum of
the foot.Course: lateral side of the neck of fibula under
cover of the upper fibres of peroneus longus.Enter anterior compartment of leg by pierce into intermuscular septum. Then pierce extensor digitorum longus & lie next to anterior tibial nerves.
Termination: dorsum of the foot by dividing into lateral and medial branches.
Muscular branches:-1)Anterior compartment of leg
a) Tibialis anteriorb) Extensor hallucis longusc) Extensor digitorum longusd) Peroneus tertius
Cutaneous branches:Lateral terminal branch end by forming thedorsal digital nerves for adjacent sides of the bigtoe and second toe.Articular branches:a) Ankle jointb) Tarsal jointc) Tarsometatarsal jointd) Metatarsophalangeal joint of big toe
EII)- LATERAL BRANCH Ends in pseudoganglion deep to the
extensor digitorum brevis. Branches again arise from the
pseudoganglion and supply the extensor digitorum brevis and the tarsal joints.
EII)-MEDIAL BRANCH Ends by supplying the skin adjoining the
first interdigital cleft & proximal joints of the big toe
F)PLANTAR NERVES Origin: termination of tibial nerve Begin deep to the flexor retinaculum Divided into two:-
Medial plantar nerveLateral plantar nerve
FI)MEDIAL PLANTAR NERVE• Larger terminal branch than lateral plantar nerve.• Lies between abductor hallucis & flexor digitorum
brevisBranch: MEDIAL PLANTAR NERVE
Muscular
Abductor hallucis; 1st layerFlexor digitorum brevis; 1st layerFirst lumbrical; 2nd layerFlexor hallucis brevis; 3rd layer
Cutaneous & vascular
Nail beds of medial 3.5 toes.Sympathetic branches to medial plantar artery
Articular Tarsometatarsal,metatarsophalangeal and interphalangeal joints of medial 2/3rd of foot
FII)LATERAL PLANTAR NERVE
Smaller than medial plantar nerve Runs obliquely between the first
and second layers of sole till the tuberosity of fifth metatarsal bone.
Then,divides into superficial and deep
Branch:
Trunk (S2,S3) Superficial branch Deep branchMuscula
rAbductor digiti minimi:1st layer
Flexor digitorum accessorius; 2nd layer
Flexor digiti minimi brevis: 3rd layer
3rd plantar interosseous: 4th layer
4th dorsal interosseous: 4th layer
1st & 2nd plantar interossei: 4th layer
1st ,2nd,3rd,dorsal interossei: 4th layer
2nd,3rd,4th lumbricals: 2nd layer
Addcutor hallucis: 3rd layer
Cutaneous &
vascular
- Nail beds of lateral 1.5 toes.Sympathetic branches to lateral plantar artery
-
Articular Tarsometatarsal Interphalangeal Metatarsophalangeal
CLINICAL ASPECTSSciatic nerve Foot drop Hamstring muscle affected Unable to do dorsiflexors and plantar flexors
of ankle joint & evertors of foot
REFERENCES 1) Chaurasia, B. (2013). Human anatomy
regional and applied dissection and clinical. (6 ed., Vol. 2). New Delhi: CBS Publishers & Distributors.
2) Cunningham Volume 1,Upper and Lower Limb. Oxford press.
3) http://medical-dictionary.thefreedictionary.com/femoral+nerve
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