The adrenal gland, of which there is one on top of each kidney, could be said to be the enforcer of the sympathetic nervous system.

The secretion of adrenaline causes the following effects:

• Pale face
• Increased muscle tone
• Increased heart rate
• Increased breathing rate
• Chest may feel ?tight'
• Heightened vision, hearing and sense of smell
• Relative ?tunnel vision' which enhances visual concentration, but  peripheral vision can be reduced
• Dilation of the pupils
• Hair follicle muscles contract, (giving the feeling of your hair standing on end)
• Shakes, your limbs may shake uncontrollably
• Dry mouth
• Voice quiver
• Difficulty swallowing
• Butterflies in the stomach
• Profuse sweating, especially the palms and the forehead
• Nausea, vomiting
• Bowel loosening, the sudden urge to go to the toilet
• Panic, a sense of impending doom
• Time distortion, everything seems to go into slow-motion