1. **Why does complete severing of the spinal cord at level C2 cause respiratory arrest?**
- The phrenic nerves, which control the diaphragm and are crucial for breathing, arise from the cervical
spinal nerves, particularly C3 to C5. Complete severing at C2 interrupts the phrenic nerves, leading to
respiratory arrest.
8. **Which nerve from the cervical plexus causes contraction of the diaphragm?**
- The phrenic nerve, derived from the cervical plexus (C3-C5), causes contraction of the diaphragm.
9. **Injury of which nerve could cause paralysis of the serratus anterior muscle?**
- Injury to the long thoracic nerve can cause paralysis of the serratus anterior muscle.
10. **What ve important nerves arise from the brachial plexus?**
- The ve important nerves arising from the brachial plexus are the musculocutaneous, axillary, radial,
median, and ulnar nerves.
11. **What is the largest nerve arising from the lumbar plexus?**
- The largest nerve arising from the lumbar plexus is the femoral nerve.
12. **Injury of which nerve causes foot drop?**
- Injury to the common bular (peroneal) nerve can cause foot drop.