What is the peripheral nervous system? Describe its two parts, and compare the sympathetic and parasympathetic nervous systems.

1. 1 · Define in one line. The peripheral nervous system is made of the nerves that link the brain and spinal cord with the rest of the body.
2. 2 · Somatic part. 12 pairs of cranial and 31 pairs of spinal nerves; controls voluntary actions of the skeletal muscles.
3. 3 · Autonomic part. Chains of nerves and ganglia beside the backbone; controls involuntary actions of the internal organs and glands.
4. 4 · Compare its two divisions.
   • Sympathetic: active in stress; faster heartbeat, wider pupils, sugar released from the liver.
   • Parasympathetic: restores normal; saliva, tears and digestion.
5. 5 · Link to daily life. Your racing heart before an exam is the sympathetic system at work.
6. 6 · Close in one line. So the two divisions complement each other to keep the body balanced.

Scoring tip: Give the numbers 12 and 31, and one clear effect for each division.