Nerves of the Lower Limb Flashcards
Which nerve supplies gluteus medius and minimus?
Superior gluteal nerve
Branching of the lumbar plexus occurs within which muscle?
Psoas major
What nerve roots contribute to the sacral plexus
Part of L4 and L5 (called the lumbosacral trunk)
S1-4
What nerve roots make up the obturator nerve?
Anterior divisions of L2,3,4
Describe the course of the common fibular nerve
It follows the head of biceps laterally (running on its medial side)
Runs superficial to the lateral head of the gastrocnemius
Winds around the neck of the fibula
Enters fibularis longus
Which nerve roots make contribute the tibial nerve?
L4,5 and S1-3 - anterior divisions`
What is the sensory supply of the deep fibular nerve?
Cleft of 1st toe
What is the sensory supply of the superficial fibular nerve?
Lower lateral leg
Dorsum of foot
What do L1 fibres innervate?
Skin of the inguinal area, groin and scrotum
Describe the course of the femoral nerve
Emerges on the lateral border of psoas
Goes under the inguinal ligament
Divides into terminal branches 1 inch after inguinal ligament
Is the femoral nerve in the femoral sheath?
No
What is the motor supply of the deep fibular nerve?
EHL
Tibialis anterior
EDL
ED brevis
Which nerve supplies the gluteus maximus?
The inferior gluteal nerve
What is the sensory innervation of the tibial nerve (name the specific branches)?
Posterior leg - sural nerve
Sole of the foot
What is endangered in a neck of tibia fracture?
The common tibial nerve
Does the common fibular nerve have a motor supply?
No, splits into deep and superficial branches that do
Describe the course of the sciatic nerve
It emerges beneath the piriformis muscle
Travels posterior to the thigh
Descends in the posterior thigh underneath biceps
Splits into terminal branches a the popliteal fossa
Pain from which structure can be referred to the inferiomedial patch of skin in the thigh?
The pelvic peritoneum
Which nerve supplies the skin on the posterior aspect of the thigh?
The posterior cutaneous nerve of the thigh
What is the course of obturator nerve?
Comes out at the medial border of psoas
Travels through the obturator canal
Enters the medial compartment of the thigh
Which nerve roots contribute to the femoral nerve?
Posterior divisions of L2,3,4
What is the sensory innervation of the obturator nerve?
Inferiomedial aspect of the thigh
What is the motor supply of the sciatic nerve?
Hamstrings - the tibial component of the nerve does all them except the short head of the biceps which is by the common fibular component
What is the motor supply of the tibial nerve?
Muscles of the posterior compartment of leg and sole of foot
Which nerves of the lumber plexus emerge from the medial aspect of Psoas?
Genitofemoral nerve
What is the sural nerve only tibial nerve?
No, also gets a contribution from the common fibular nerve
What structural feature means that pregnant women and obese people something get tingling on the lateral thigh?
The lateral cutaneous nerve of the thigh runs close to the ASIS and can get wedged against it
What is the sensory supply of the femoral nerve and the name of the branches that supply them.
Anteriomedial thigh - medial and intermediate cutaneous branches of the thigh
Medial aspect of knee, leg and ankle - saphenous nerve
Which nerve root contribute to the sciatic nerve?
L4,5 and S1-3 - anterior and posterior branches
What is the course and branches of the genitofemoral nerve?
Comes out onto the anterior compartment of psoas major
Branches into the femoral branch and genital branch
What is the motor innervation the femoral nerve?
Quadraceps
Sartorius
Pectineus (also receives supply from medial compartment)
What are the effects of severing the iliohypogastric nerve and ilioinguinal nerve?
Increased chance of inguinal herniation due to loss of the ability to contract the roof of the canal during abdo wall contraction (and increased intra-abdominal pressure)
Describe the course of the tibial nerve
Its descent is continuous with that of the sciatic nerve - through the popliteal fossa
Beneath the fibrous arch of the soleus
Descends between the post. and ant compartments of the leg
Hooks posterior to the medial malleolus
Onto the sole of the foot
How does the femoral nerve supply the muscles of the anterior compartment of the thigh?
Sends an individual branch to each muscle
Which spinal root contribute to the lumbar plexus?
Ventral rami of L1-L4
Which nerves of the lumber plexus emerge from the medial border of Psoas?
Obturator nerve
What does the genitofemoral nerve supply?
Supplies the area of skin directly beneath the inguinal ligament, over the femoral triangle
Which nerve supplies the muscles of the lateral compartment of the leg?
Superficial fibular nerve
Which nerves of the lumber plexus emerge from the lateral border of Psoas?
Ilioinguinal and Iliohypogastric
Lateral cutaneous nerve of the thigh
Femoral nerve
What are the terminal branches of the sciatic nerve?
The common fibular
The tibial
On what muscle does the sacral plexus form?
The piriformis
Which nerves of the lumbar plexus run on top of the iliacus muscle?
Lateral cutaneous nerve of thigh
Femoral nerve
Why does IM injection given in the lateral thigh now, instead of the superiolateral gluteal region as previous?
Because there is risk that the sciatic nerve splits early and common fibular nerve can come out above the piriformis and be close to that part of the gluteal region
How does a damaged common fibular nerve present?
Dropped foot
- inability to dorsiflex, extend or evert the foot
Which nerve roots contribute the common fibular nerve?
L4-5 and S1-2 posterior divisions
Which nerve roots contribute to the lateral cutaneous nerve of the thigh?
L2 and L3
What does the ilioinguinal and iliohypogastric nerves supply?
Structures on the posterior abdo wall
Lower fibres of transversis abdominis and internal oblique
Which muscles does the obturator nerve supply?
The adductors and part of pectineus
