C. Major Nerves of the Nerve Plexuses Identify the nerve plexus from which each nerve originates. \( \qquad \) 1. femoral n. \( \qquad \) 2. sciatic \( n \). \( \qquad \) 3. phrenic \( n \). \( \qquad \) 4. ulnar \( n \). brachial plexus 5. axillary n . \( \qquad \) 6. tibial n . \( \qquad \) 7. obturator n .

1. **Femoral nerve** - Originates from the lumbar plexus, specifically from the roots \( L2-L4 \). 2. **Sciatic nerve** - Originates from the sacral plexus, with contributions from roots \( L4-S3 \). 3. **Phrenic nerve** - Originates from the cervical plexus, primarily from the roots \( C3-C5 \). 4. **Ulnar nerve** - Originates from the brachial plexus, specifically from the medial cord (roots from \( C8-T1 \)). 5. **Axillary nerve** - Originates from the brachial plexus, specifically from the posterior cord (primarily \( C5-C6 \)). 6. **Tibial nerve** - Originates from the sacral plexus, with contributions commonly from \( L4-S3 \). 7. **Obturator nerve** - Originates from the lumbar plexus, specifically from the roots \( L2-L4 \).