how do spiders that bite, inject their venom (if they have any)??

Question: how do spiders that bite, inject their venom (if they have any)??
- Keywords:
  bite,
  inject,
  spider,
  venom
Asked by howestwh to David, Helen, Ian, rhysphillips, Sarah on 22 Jun 2011.
- Rhys Phillips answered on 14 Jun 2011:
  
  Biting pierces the skin and allows them to deposit the venom into your body. I suspect one of the others can give a better, more detailed answer than that though!
- Helen Fletcher answered on 22 Jun 2011:
  
  Most venemous spiders have fangs, which are usually hidden away, but when it catches prey, the spider sticks the fang into the prey’s body. This causes venom to be released from a gland further inside, and that is squeezed down a hollow duct in the middle of the fang and out of a small opening at the end: just like when you get an injection, but less friendly. The venom contains chemicals that paralyse or kill the prey, making it easier for the spider to eat. Some species wrap their prey up in silk first to make things easier. These little ‘parcels’ have their uses: the spiders can take them back for their babies, or give them to potential suitors to woo them. Who needs chocolates and roses?
- Ian van der Linde answered on 22 Jun 2011:
  
  They have hyperdermic fangs that are hollow inside for delivering the venom. Just like that guy from Twighlight, except that he can also suck.

Question: how do spiders that bite, inject their venom (if they have any)??