Explanation of what is going on in the nervous system during certain tasks

[ktrah]

My teacher asked me today to describe the process that occurs (what happens with the brain and stuff) when you pick up a pen and put it down. I was only able to say something like the sensory neurons transmit the information to the brain and the primary motor cortex sends a motor neural impulse back to make the hand move. But my teacher gave me this really detailed explanation of what is happening (it included the parts of the brain the information would be processed) and told us that we would be explaining things like this (I think we're given scenarios and we have to explain what's going on) for the SAC, which is next Thursday. So I was wondering would be able to explain what is happening for this or any other example, or if you just have any general advice for the SAC it would be much appreciated. Thanks

[Slumdawg]

I'll give this a crack and hopefully someone can verify how right I am!

Let's use the pick up pen as an example.

Firstly, you must understand that the CNS is made up of the brain and the spinal cord, receives and transmits messages to and from the PNS.

The Brain is our master organ which is responsible for everything we think and do.
and the Spinal Cord connects the BRAIN and the PNS.

You should know by now that the PNS main functions is to receive SENSORY AFFERENT neurons FROM your senses from muscles and send MOTOR EFFERENT neurons TO your muscles. The PNS, then as described above, is connected to your Spinal Cord, which is connected to your brain which makes up the CNS. (This is really what you're looking for).
 

EXAMPLE:

When you go and pick up a pen, let's say with the left hand, neural messages from your right cerebral hemisphere is travelled down your SPINAL CORD (which is connected to the PNS), to the PNS, SENDING MOTOR EFFERENT neurons to your hand to pick up the pen.

At the same time, from your hand, through your SENSORY AFFERENT neurons, to the spinal cord, up back to the brain so you can RECEIVE the feeling of the metal outer layer of the pen.

When you put it back down same thing occurs but of course there will be changes in the muscle movements.


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I tried to explain it simply and caps lock'd the main points, but it's important to basically know that the PNS connects the CNS ( brain and spinal cord) to your muscles and organs, and the PNS is what RECEIVES feel, touch, pain, and SENDS info to the muscles, organs and glands to move.




PS: Please someone verify if what I've said is right, I'm just like any other '12 Psych student atm!

Slight correction, neurons aren't ever sent anywhere as you've described a couple of times. Simply messages are carried along the neurons, they themselves dont physically really travel anywhere. Also, to make that answer more specific and therefore much more likely to get full marks you should also mention the message at the beginning would originate in the right primary motor cortex, whilst the final message regarding sensory information from the sensory receptors in your hand would be sent to the right somatosensory cortex rather than the more broad description of 'right hemisphere'.

Also, a few corrections to your paragraph below:
"SENSORY messaages from your sensory receptors travel TOWARDS the brain via afferent nerves (PNS) to eventually reach the somatosensory cortex (CNS). On the other hand, motor messages begin in the primary motor cortex of the brain (CNS) and travel via efferent nerves (PNS) to your skeletal muscles"

But good job overall with your answer, on the whole you've mentioned some great points

[dzzhao]

Thank you so much! I'm always up for gaining feedback and correcting mistakes/weaknesses, and yes I fully understand what you're saying now, much appreciated for the feedback!

[depressedchild]

hey there, i need on this... say i have a bee sting, what would be the steps that take part in the central nervous system?