Some science behind the scenes

Sympathetic nervous system

The sympathetic nervous system maintains our flight or fight response.  The nerves here have adrenergic nerve endings and use noradrenaline as their neurotransmitter.  When this nervous system is stimulated it can:

  • Increase the heart rate – so that we get more oxygen going to the muscle cells ready for flight
  • Dilate the pupils – so we can see better in perhaps low light when we flee
  • Constrict blood vessels to the gut and inhibit the stomach, the pancreas and intestine as well as urination – so we have no need to poo or wee during flight
  • Relax the bronchi in the lungs, so lung capacity expands to take in more oxygen for our cells
  • It also promotes ejaculation – but here I think we have a strange by product of a far age flee mechanism, if we are going to die then we might as well pro-create before we die.



For iPad/iPhone users: tap letter twice to get list of items.