Gross Anatomy- Innervation of Anterior and Medial Thigh

Question 1

Describe the innervation of the Femoral n

Answer 1

o From posterior divisions VPR L2-4
o Located in femoral triangle

Question 2

Describe the Femoral Cauda equina

Answer 2

 Collective name for numerous branches of femoral n. in femoral triangle
o Supplies anterior compartment mm.

Question 3

Describe the Saphenous n

Answer 3

 Runs in adductor canal
 Does not pass through adductor hiatus
 Passes medially at knee
 Does not supply anything in thigh
o Anterior cutaneous branches
o Medial cutaneous branches

Question 4

Desribe the Obturator n

Answer 4

o From anterior divisions VPR L2-4
o Exits obturator canal
o Divides into anterior and posterior divisions
 Separated by adductor brevis m.
 Anterior division:
• Supplies adductor longus, brevis and gracilis mm.
 Posterior division:
• Supplies adductor part of adductor magnus and obturator externus mm.
o Sensory to skin of medial thigh just above knee

Question 5

Describe the Lateral femoral cutaneous n.

Answer 5

o From VPR L2-3
o Supplies skin on anterior and lateral thigh

Question 6

Describe the **Genitofemoral n. **

Answer 6

o From VPR L1-2
o Femoral branch –
 Supplies skin over lateral femoral triangle

Question 7

Describe the Ilioinguinal n.

Answer 7

o From VPR L1
o Supplies skin of upper medial thigh

Question 8

Explain an injury to the Femoral n.

Answer 8

• May be injured by:
o Pelvic fracture
o Psoas abscess
o Gunshot or other penetrating thigh wound
• Results in:
o Weakened flexion of thigh
o Loss of leg extension
o Sensation to anterior and parts of medial thigh
 Anteromedial leg and foot via saphenous n.
• Difficult to walk uphill or stairs
o Person will push against thigh to force knee into extension
• Patellar ligament and knee jerk reflex:
o Myotatic (deep tendon) reflex
o Striking patellar l. of flexed leg should result in extension of knee
 Afferent and efferent limbs of reflex arc are via femoral n.
 If femoral n. or L2-4 spinal cord segments are damaged, it will affect this reflex
• May also be diminished by peripheral nerve disease