Lp #99 The Sciatic Nerve Flashcards
- largest nerve in body: 2cm wide
- major part of sacral plexus
- originates from ventral rami of L4-S3
- components:
- tibial n & common fibular n
- bound together in common sheath
Sciatic nerve
Sciatic nerve pathway:
- ventral rami ___-___
- exits pelvis via ______ ____ ______ inferior to ______
- travels deep to ____ ____ B/w _____ _____ & ______ ______
- descends along posterior thigh b/w _____ & ____ ______
- splits above popliteal fossa into tibial & _____ _____ (_____) __
- L4-S3
- Greater sciatic foramen & Piriformis
- Glute max & greater trochanter & Ischial tuberosity
- Hamstrings & Adductor Magnus
- Common fibular (peroneal) nn
Cutaneuous Innervation:
Most of lower limb
Motor Innervation:
- semitendinosus
- semimembranosus
- biceps femoris
- adductor Magnus- hamstring portion
Tibial nerve pathway:
- Ventral rami ___-___
- down posterior _____
- enters _____ _____
- descends leg deep to _____
- enters foot posterior to ___ ____
- splits into medial & lateral ____ _____
- L4-S3
- Thigh
- Popliteal fossa
- Gastrocnemius
- Medial malleolus
- Plantar branches
Tibial nerve sensory Innervation:
- ________: skin of posterolateral leg & dorsolateral foot
- _______& ____ _____ __: skin of plantar aspect of foot
- ______ ______: knee, distal tibiofibular joint, ankle joint
- sural n
- medial & lateral plantar nn
- articular branches
Motor Innervation tibial nerve:
- superficial & deep posterior compartments of leg
- plantar mm of foot
Tibial nerve branches
- medial sural cutaneuous nerve
- sural nerve
- arises in popliteal fossa
- meets w/ a branch of common fibular nerve to form sural nerve
Medial sural cutaneous nerve
Innervates skin of posterolateral leg & dorsolateral foot
Sural nerve
Tibial motor Innervation:
Superficial & deep posterior compartments of the leg?
- gastrocnemius
- soleus
- plantaris
- popliteus
- Tibialis posterior
- flexor digitorum longus
- flexor hallucis longus
Tibial nerve motor Innervation:
*plantar mm of foot- medial plantar n?
- flexor digitorum brevis
- abductor hallucis
- flexor hallicis brevis
- 1st lumbrical
Tibial nerve motor Innervation:
Plantar mm of foot- lateral plantar n?
- Quadratus plantae
- abductor digit minimi
- flexor digit minimi
- opponents digit minimi
- adductor hallucis
- plantar Interossei
- dorsal interossei
- lumbricals
- originates from ventricular rami L4-S2
- lateral, smaller branch of sciatic n
Common fibular nerve
Common fibular nerve: Cutaneous Innervation
- superficial fibular n?
- deep fibular n?
Superficial:
- skin on anterolaterla surface of leg
- skin of dorsum of foot & ankle (not web between 1st & 2nd toes)
deep:
- skin o dorsal web space b/w 1st & 2nd toes
