Lecture 9.3 Flashcards
Where is the lumbar plexus located?
Within psoas major
Where is the sacral plexus located?
Deep to piriformis
What division of spinal nerves forms the lumbar plexus?
Ventral rami (L 1 - 4)
What nerves run out of lateral border of psoas major?
Ilioinguinal, iliohypogastric, and femoral nerve
What nerve runs onto anterior surface of psoas?
Genitofemoral nerve
What nerve runs medially to psoas major?
Obturator nerve
What does the genitofemoral nerve supple?
Genital genitofemoral nerve supplies the spermatic cord
Femoral genitofemoral nerve supplies skin over the femoral triangle
Which nerve runs under the inguinal ligament and divides into many divisions right after?
femoral nerve
Where does the lateral cutaneus nerve run after it leaves psoas?
through the inguinal ligament right under ASIS.
What is the pneumonic to remember the nerves of the lumbar plexus?
I (twice) Get Laid On Fridays I= Ilioinguinal + Iliohypogastric G= Genitofemoral L= Lateral Cutaneous Nerve O= Obturator F= femoral
What are the branches of the sacral plexus?
Parietal (exits sciatic foramen into gluteal region)
Visceral (innervates pelvic viscera)
Where does the femoral nerve split into all it’s braches?
In the femoral triangle right after the inguinal ligament
What are the boundaries of the femoral triangle?
Superiorly: Inguinal ligament
Medially: adductor longus
Laterally:sartorius
What muscles does the femoral nerve innervate?
Quads, sartorius, and pectineus
What sensory branches does the femoral nerve form and what do they innervate?
anterior cutaneous branch; innervates anteromedial thigh
saphenous; innervates medial leg and foot up to the first MT/P joint
Also sends articular branches to hip and knee
What are the contents of the femoral triangle?
femoral nerve, artery, and vein.
Femoral vein is contained within the femoral sheath which contains dead space for the vein to expand.
What is a femoral hernia?
Occurs when abdominal contents fall into the femoral sheath.
What muscle innervates articularis genus?
femoral nerve
What nerve innervates the lateral part of the thigh?
Lateral cutaneus nerve
What nerve innervates the gap that the femoral nerve leaves on the medial thigh?
obturator nerve
What are the branches of the saphenous nerve at the medial leg called?
medial crural cutaneous branches of the saphenous nerve
What spinal nerves form the femoral nerve?
L2, 3, 4; Posterior divisions of lumbar plexus
What spinal nerves form the obturator nerve?
L2, 3, 4 Anterior divisions
Where does the pectineus originate and insert and what are it’s functions?
Origin: pectineal line
Insertion: Pectineal line of the femur
Innervation: femoral nerve, with 20% of the population have a branch of the obturator nerve)
What nerve innervates hamstrings? Be as specific as possible
Tibial portion of sciatic nerve for semitendinosus, semimembranosus, + long head of biceps femoris.
Fibular portion of sciatic nerve for short head of biceps femoris.
What nerve is responsible for cutaneous innervation of posterior thigh?
Posterior cutaneous nerve
What spinal nerves form the sciatic nerve?
L 4, 5, S 1->3 anterior and divisions
What structure/s is/are vulnerable from posterior dislocation of hip joint?
Sciatic nerve
Where does the tibial nerve travel after the popliteal fossa?
Posterior to tibialis posterior and anterior to soleus -> moves to foot behind the medial malleolus to form the plantar nerves
What are the motor innervations of the tibial nerve?
Muscles of posterior leg and sole of the foot
What is the name of the foot’s nerve divisions that innervate the sole of the foot
Medial calcaneal nerve
Medial plantar nerve
Lateral plantar nerve
What are the sensory divisions of the tibial nerve and what to they innervate?
The sural nerve (innervates posterolateral leg and lateral foot)
Medial calcaneal, medial plantar, lateral plantar (innervate the sole of the foot)
What are the structures behind the medial malleolus?
Tom Dick And Very Naughty Harry
Tibialis Posterior, FDL, posterior tibial Artery, great saphenous Vein, tibial Nerve, and FHL
What spinal nerves form the Common Fibular Nerve?
L4,5 S1,2
Where in the popliteal fossa does the common fibular nerve pass?
medial to biceps tendon and then superficial to gastrocnemeus lateral head.
Where does the common fibular nerve split into its terminal branches?
Right after passing the head of the fibula. This occurs near the fibularis longus.
The common fibular nerve gives a communicating branch to which nerve?
lateral sural nerve.
What does the deep fibular nerve innervate?
the anterior compartment muscles
skin of the big toe cleft.
What does the superficial fibular nerve innervate?
lateral compartment muscles
skin of anterolateral leg and dorsum of the foot.
What does the sural nerve innervate?
the posterolateral leg skin
Where in the leg does the deep fibular nerve run?
Near the interosseus membrane and then passes through the extensor retinaculum to supply the hallucis cleft
What nerve is the sural nerve a branch of?
tibial nerve
What is significant to remember about Lateral Cutaneous Nerve and Posterior Cutaneous Nerve?
They emerge directly from the plexus and innervate the skin.
