NETTER - Neuroscience Flash Cards

Sciatic and Posterior Femoral
Cutaneous Nerves
1. Posterior femoral cutaneous nerve
2. Inferior cluneal nerve
3. Perineal branches
4. Tibial segment of the sciatic nerve
5. Tibial nerve
6. Medial sural cutaneous nerve
7. Sural nerve
8. Tibial nerve in the ankle
9. Medial and lateral plantar nerves
10. Lateral sural cutaneous nerve
11. Common peroneal nerve
12. Common peroneal segment of the sciatic nerve
13. Sciatic nerve
14. Superficial peroneal nerve
Comment: The superior and inferior gluteal nerves branch
proximally, just before the formation of the sciatic nerve. The
superior gluteal nerve aids in abduction and inward rotation and
some outward rotation of the thigh, as well as in flexion of the upper
leg at the hip. The inferior gluteal nerve aids in extension of the thigh
at the hip and to outward rotation of the thigh; a lesion results in
difficulty climbing stairs and rising from a sitting position. The sciatic
nerve (L4–S3) provides motor innervation to the biceps femoris,
semitendinosus, and semimembranosus muscles (hamstrings) and
regulates flexion of the lower leg; a major lesion results in weakness
of leg flexion and weakness of all muscles below the knee. A sciatic
nerve lesion also may result in loss of cutaneous sensation on the
posterior thigh, posterior and lateral leg, lateral foot, and sole of
the foot. A lesion of the posterior femoral cutaneous nerve (S1–S3)
results in loss of sensation to the posterior thigh, lateral part of the
perineum, and lower portion of the buttock.
Regional Neuroscience See book 9.34