GLOSSARY

The sympathetic nervous system is the part of the autonomic nervous system that prepares the body for physical activity, stress, and emergencies (“fight or flight”), and in exercise it plays the key role in raising heart rate, blood pressure, and energy supply.

Structure

• Origin: the thoracic and upper lumbar spinal cord (T1–L2), the “thoracolumbar outflow”.
• Sympathetic chain: ganglia on both sides of the spine.
• Transmitters: acetylcholine in the ganglia and noradrenaline at the organs (except sweat glands, which use acetylcholine).
• Adrenal medulla: a kind of modified ganglion that releases adrenaline (about 80 percent) and noradrenaline into the blood.

Main Effects