The ANS, when it works properly that is, is mainly what is responsible for both enhancing the pleasure in our lives and is what protects us from harm.
Imagine where’d be without the ANS to communicate with the brain
when we’re being intimate with our partner: it just wouldn’t be the same, would it? When it doesn’t work properly, however, it can either cause loss of sensation in parts of the body or worse, it could make it inadvertently cause us harm by not warning us about the danger that is present.
There are two main types of nerves within the autonomic nervous system, the ones that give us our sense of touch and ones that inform us that our body is in pain, otherwise known as sensory nerves and pain nerves, respectively. The sensory nerves pick up signals such as temperature and pressure, and if these signals reach certain (critical) levels, then the pain nerves are also activated and their signals are transmitted to the brain.
Here’s a scenario for you to ponder: A common example to demonstrate both these systems in action is the withdrawl reflex: have you ever noticed your hand quickly whisked away after accidentally touching a naked flame?
This would be what happens within a matter of seconds:
This is what happens normally. Think what would happen though, if the signal could not get through for some reason. Have you ever tried to send an urgent message through to someone on the phone (either by calling or texting them) and not being able to get through? You would either get a busy signal (if the recipient is talking to someone else at the time) or a message saying the person is unavailable (if their phone is flat), so you would get sent straight to voice-mail, if they have any.
How is this relevant, you may ask? Well, the nervous system is similar: the signal needs to be able to get through unobstructed to the brain in order to be able to react to the urgent message in a reasonable amount of time.
In this case, if the person wasn’t able to perceive the danger in time, the person would ultimately receive burns to their hand (OUCH!) This can happen if the nerves were physically or chemically cut off from the brain. In the extreme case, there is a medical condition known as cipa (that is an acronym for congenital insensitivity to pain) which can result in a complete lack of pain perception.
The normal pain route is discussed in more detail in NTs: Substance P.