Nerves of the Lower Limb Flashcards
What spinal nerves make up the lumbar plexus?
ventral rami of L1-4
Where is the lumbar plexus formed?
within psoas major
Which nerves emerge from the lateral border of psoas major?
ilioinguinal and iliohypogastric nerves, lateral cutaneous nerve of thigh and femoral nerve
Which nerve emerges onto the anterior surface of psoas major?
genitofemoral nerve
Which nerve emerges from the medial border of psoas major?
obturator nerve
What nerve roots are the ilioinguinal and iliohypogastric nerves?
L1
What is the cutaneous supply of the ilioinguinal and iliohypogastric nerves?
skin of the inguinal region and front of the scrotum (L1)
What is the motor supply of the ilioinguinal and iliohypogastric nerves?
lower most fibres of internal oblique and transversus abdominus
If the ilioinguinal and iliohypogastric nerves are cut what is the patient at risk of?
an indirect inguinal hernia
What are the nerve roots of the lateral cutaneous nerve of thigh?
L2,3
Where and how can the lateral cutaneous nerve of thigh be compressed?
as it goes under the inguinal ligament in pregnancy or obesity
Where does the femoral nerve travel?
in the gutter between iliacus and psoas
What are the nerve roots of the femoral nerve?
L2,3,4
What are the nerve roots of the genitofemoral nerve?
L1,2 (L1 is the femoral branch and L2 is the genito branch)
What does the femoral branch of the genitofemoral nerve supply?
the area of skin immediately beneath the inguinal ligament
What does the genital branch of the genitofemoral nerve supply?
the spermatic cord
What nerve roots make up the sacral plexus?
S1-4
Where does the sacral plexus form?
on piriformis on the posterior wall of the pelvis
What is the lumbosacral trunk?
the nervous tissue that connect the lumbar plexus to the sacral plexus - contains part of L4 and all of L5
What is the motor supply of the femoral nerve?
quads, sartorius and pectineus
What is the sensory supply of the femoral nerve?
anteromedial thigh (via medial and intermediate cutaneous nerve of thigh) and medial side of knee, leg and ankle up to the 1st metatarsophalangeal joint (via saphenous nerve)
What is the articular supply of the femoral nerve?
hip and knee
Where does the femoral nerve divide into its terminal branches?
2.5cm below the inguinal ligament
Where does the femoral nerve travel in the femoral triangle?
outside the femoral sheath lateral to the vascular structures
What is the motor supply of the obturator nerve?
adductor muscles (+ pectineus - hamstring part of adductor magnus)
What is the sensory supply of the obturator nerve?
inferomedial thigh
What is the articular supply of the obturator nerve?
hip
Where does the obturator nerve run in the thigh?
either side of adductor brevis
What pain can be referred to the sensory area of the obturator nerve?
pelvic pathology
What nerve supplies the skin over the back of the thigh?
posterior cutaneous nerve of thigh (branch of sacral plexus)
What nerve roots make up the sciatic nerve?
L4,5 S1-3 anterior and posterior divisions
Where does the sciatic nerve emerge in relation to piriformis?
beneath piriformis
Where does the sciatic nerve divide and what does it divide into?
divides at the top of the popliteal fossa into the tibial and common fibular nerves
What is the motor supply of the sciatic nerve?
hamstrings (all from the tibial branch except short head of biceps)
What is the articular supply of the sciatic nerve?
hip
What is the nerve supply of glut med and glut min?
superior gluteal nerve
Where does the superior gluteal nerve emerge in relation to piriformis?
above piriformis
What is the nerve supply of glut max?
inferior gluteal nerve
Where does the inferior gluteal nerve emerge in relation to piriformis?
below piriformis
Where does the posterior cutaneous nerve of thigh emerge in relation to piriformis?
below piriformis
What nerve roots contribute to the tibial nerve?
anterior divisions of L4,5 S1-3
What is the path of the tibial nerve?
travels down the back of the leg - beneath the fibrous arch of soleus, passes posterior to the medial malleolus, and divides into the medial and lateral plantar nerves
What are the branches of the tibial nerve?
sural nerve, medial calcaneal, medial and lateral plantar nerves
What is the motor supply of the tibial nerve?
posterior leg and sole of foot
What is the sensory supply of the tibial nerve?
posterior leg (via sural nerve) and sole of foot (via medial calcaneal, medial and lateral plantar nerves)
What is the cutaneous area supplied by the lateral plantar nerve?
the lateral sole of the foot and the lateral 1.5 digits
What is the cutaneous area supplied by the medial plantar nerve?
the medial sole of the foot and the medial 3.5 digits
What nerve roots contribute to the common fibular nerve?
L4,5 and S1,2 posterior divisions
What is the path of the common fibular nerve?
runs medial to biceps, superficial to the lateral head of gastrocnemius, winds around the neck of the fibula, goes onto fibularis longus and then divides into terminal branches
What are the branches of the common fibular nerve?
superifical and deep fibular nerves
What is the sensory supply of the common fibular nerve?
upper lateral leg via the lateral sural cutaneous nerve
What is the motor supply of the deep fibular nerve?
anterior compartment of leg, extensor digitorum brevis
What is the sensory supply of the deep fibular nerve?
first toe cleft
What is the articular supply of the deep fibular nerve?
ankle and foot
What is the motor supply of the superficial fibular nerve?
lateral compartment of leg
What is the sensory supply of the superficial fibular nerve?
lower lateral leg and dorsum of foot
What is at risk in a fracture of the neck of fibula and what are the symptoms?
can damage the common fibular nerve - get foot drop - can’t dorsiflex and can’t evert
