Science Questions

Why is a king cobra not affected by its own venom? Narinda, India

Chris -  It is because lots of people say that snakes are in some way immune but the reason is the same reason that you don’t die from your own gastric stomach juices.  If they get in to the wrong part of your body they will kill you very effectively.  When people have pancreatitis which is where the pancreas which is connected to your gut and secretes all the enzymes that break down your lunch.  When that gets inflamed and the degrative juices get into your blood stream this can cause quite sever damage to your body and it can cause lung damage and other forms of inflammation.  That’s very bad.

The snake uses the same strategy that you do.  It makes the venom which is a kind of protein.  It’s a tiny protein which it can make lots of and it has it in a little sac which it stores up in its head.  It’s connected to the two fangs at the front which are hollow.  When the snake bites you this sac squirts a venom out, down the teeth and into your skin.  If you look at the venom gland it’s lined by very specialised cells that keep the venom there and not in the snake’s body.  There should be no access between the venom and the snake’s body.  When I spoke to someone who is a venom expert they said you can also detect antibody to their own venom in some snakes.  Just in case some spilled over I think they have this back-up plan which is they have some antivenom built in to mop it up and make sure it doesn’t go any further.

July 2008