Sudden Reflexes?

[MsKnuckles]

It's the second time that I was about to slip over a wet floor now... and twice I managed to prevent myself from falling by using the table next to me for support (and that happened before I could even realize what was happening! It happened too fast for me to think) Twice I was surprised.

I know everyone has sudden reactions which come automatically. What do you call this? Reflex right?
What is it?? Instinct?

For instance: I tried to look like I was throwing something at my friend a few times... and every time I tried when I knew she wasn't aware of it... she automatically raised her hand to shield herself.

Same thing happens when people hear a loud bang. They automatically duck or cover their heads.And it's something you have no control over... it just happens.

Can you call this, non-thinkable reflexes? I forgot the biological word.
what causes it?

[HITMAN]

Can you call this, non-thinkable reflexes? I forgot the biological word.
what causes it?

The examples you have mentioned are Withdrawal Reflexes


what causes it? .


Same thing happens when people hear a loud bang. They automatically duck or cover their heads.And it's something you have no control over... it just happens

Let us explain how it happens in a simple way by analyzing the above example.

The reflex is as a biological/electrical system in our body, this system links the stimulus to the end response through a neural path. In more simple terms:

The loud noise you hear is the stimulus to which the receptors in your ears make the afferent nerves send impulses to your CNS, and the CNS in return creates the response which is covering the ears

[MsKnuckles]

Hitman... great info.
so what part of the brain do those signals go to?

-I hear some people have better reflexes than others... this is due to what?

[Jeff]

But how does the brain or the ears know which things to send to the reflex system and which to send to other places? How does it recognize "BANG!" and send that to the right place so we duck?

[PickledPablo]

Ir's due to past experiences, when I heard a bang I saw an explosion and had to duck to avoid injury. so whenever I hear a bang my mind realizes the danger and sends info for my body to duck automatically.

[Nella]

interesting! :lift:

[HITMAN]

Hitman... great info.
so what part of the brain do those signals go to?

First of all, I would like to make it clear that I didn't say brain but I said CNS (central nervous system). CNS has two parts: Brain & spinal cord.

Answering your question, the signals go to the spinal cord


I hear some people have better reflexes than others... this is due to what?

Each one of us has a different thershold to different stimuli

[HITMAN]

But how does the brain or the ears know which things to send to the reflex system and which to send to other places? How does it recognize "BANG!" and send that to the right place so we duck?

Jeff, if I take a sharp pin & poke your finger with it quite hard, the pain receptors on your finger will send impulses & withdrawal reflex will make you move your finger & even maybe punch me in return ;)

The pain receptors of the finger are sending the impulses thus the CNS's spinal cord creates the response which is moving your finger

[FaHaD]

excellent topic...

another wonderful example is closing the eyes while sneezing..this protects the eye from nasal secretions


The above examples are called " simple reflex"

another main example of reflexes are called " conditional reflexes" related to learning. A stimulus that produces a simple reflex response becomes linked with another, possibly unrelated, stimulus. For example, a dog may salivate (a reflex action) when it sees its owner remove a tin-opener from a drawer because it has learned to associate that stimulus with the stimulus of being fed.

http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab9/IMAGES/DRAW05.JPG

Look at structure no. 3 in the above picture. it is called the interneuron.. in the absence of stimulus the reflexes are inhibited. Some inhibitory neurons from the brain aid the inhibition. This is why patients with stroke or spinal cord injury get strong reflexes due to the loss of these inhibitory neurons.

such findings are used in diagnosis the level of CNS damage.. the damage is called : Upper motor neuron lesion.

for more information look at teh following image

http://instruct.uwo.ca/anatomy/530/stretchr.gif