Sacral Plexus Flashcards
The sacral plexus is made up of which nerve roots?
L4 and 5, S1-S4
Where is the sacral plexus housed?
Anterior to the sacrum
Primary branches of the sacral plexus
Superior and inferior gluteal nerves, sciatic nerve.
Secondary branches of the sacral plexus
Nerves to piriformis, gemellus superior and quadratus femoris
Path of the superior gluteal nerve
Primary branch of the sacral plexus. Exits the pelvis, then enters the gluteal region through the greater sciatic foramen superior to the piriformis
Muscles innervated by the superior gluteal nerve
Gluteus medius, minimum and TFL
Pathway of the inferior gluteal nerve
Primary branch of the sacral plexus. Exits the pelvis, then enters the gluteal region through the greater sciatic foramen, inferior to the piriformis.
Muscles innervated by the inferior gluteal nerve
Gluteus maximus
Branches of the sciatic nerve
Tibial and common peroneal. The common peroneal then divides into the deep and superficial peroneal nerves.
Path of the sciatic nerve
Primary branch of the sacral plexus. Exits the pelvis, then enters the gluteal region through the greater sciatic foramen deep to the piriformis. Travels down the posterior thigh, then splits just proximal to the popliteal fossa.
Muscles innervated by the sciatic nerve
Hamstrings, posterior fibers of the adductor magnus.
Tibial nerve
Branch of the sciatic nerve. Travels through the popliteal fossa as the lateral neurovascular structure, then down the posterior leg, posterior to the medial malleolus.
Muscles innervated by the tibial nerve
Popliteus, gastrocnemius, soleus, FDL, FHL, tibialis posterior, plantaris
Common peroneal nerve
Branch of the sciatic nerve. Follows the tendon of the biceps femoris. At the fibular head, it splits into deep an superficial branches.
Structures innervated by the common peroneal nerve
The non-contractile structures of the knee.
Superficial peroneal nerve
Branch of the common peroneal nerve. Travels down the lateral compartment of the leg and into the dorsum of the foot.
Deep peroneal nerve
Branches off of the common peroneal nerve. Travels down the anterior compartment of the leg into the dorsum of the foot.
Muscles innervated by the superficial peroneal nerve
Peroneus longus and brevis
Pathway of the secondary nerves of the sacral plexus
Travel through the greater sciatic foramen deep to the piriformis
Nerve to piriformis
Secondary nerve of the sacral plexus which innervates the piriformis.
Muscles innervated by the deep peroneal nerve
Tibialis anterior, EDL, EHL, peroneus tertius
Nerve to obturator internus
Secondary nerve of the sacral plexus which innervates the obturator internus and gemellus superior
Nerve to quadratus femoris
Secondary nerve of the sacral plexus which innervates the quadratus femoris and gemellus inferior.
Greater sciatic foramen
Created by the greater sciatic notch, lateral sacrum and sacrospinous ligament
Contents of the greater sciatic notch
Piriformis, superior and inferior nerve, artery and vein, the sciatic nerve, 3 secondary nerves
Popliteal fossa
Created by biceps femoris, semitendinosus and semimembranosus, both heads of the gastrocnemius
Contents of the popliteal foss
Popliteal artery and veins and the tibial nerve
Tom, Dick AN Harry
Mneumonic for the structures which pass behind the medial malleolus
Tom
Tibialis posterior
Dick
flexor Digitorum longus
AN
Artery and Nerve. Posterior tibial artery and tibial nerve
Harry
flexor Hallucis longus
