Chapter 13
The Peripheral Nervous System and Reflex Activity
507
13
(a) Ventral rami and major branches of the lumbar plexus
Iliohypogastric
L
1
L
2
L
3
L
4
L
5
Ilioinguinal
Genitofemoral
Lateral femoral
cutaneous
Obturator
Femoral
Lumbosacral
trunk
Lateral
femoral
cutaneous
Anterior
femoral
cutaneous
Saphenous
Obturator
Iliohypogastric
Ilioinguinal
Femoral
Ventral rami
Ventral
rami:
(b) Distribution of the major nerves from the
lumbar plexus to the lower limb
Figure 13.11
The lumbar plexus.
(Anterior view.)
Table 13.5
Branches of the Lumbar Plexus
(See Figure 13.11 and Appendix G)
NERVES
VENTRAL RAMI
STRUCTURES SERVED
Femoral
L
2
–L
4
Skin of anterior and medial thigh via
anterior femoral cutaneous
branch; skin of medial
leg and foot, hip and knee joints via
saphenous
branch; motor to anterior muscles
(quadriceps and sartorius) of thigh and to pectineus, iliacus
Obturator
L
2
–L
4
Motor to adductor magnus (part), longus, and brevis muscles, gracilis muscle of medial
thigh, obturator externus; sensory for skin of medial thigh and for hip and knee joints
Lateral femoral cutaneous
L
2
, L
3
Skin of lateral thigh; some sensory branches to peritoneum
Iliohypogastric
L
1
Skin of lower abdomen and hip; muscles of anterolateral abdominal wall (internal
obliques and transversus abdominis)
Ilioinguinal
L
1
Skin of external genitalia and proximal medial aspect of the thigh; inferior abdominal
muscles
Genitofemoral
L
1
, L
2
Skin of scrotum in males, of labia majora in females, and of anterior thigh inferior to
middle portion of inguinal region; cremaster muscle in males
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