- quick quiz about NS and neuron
- performed simple activities related to reflex arcs (p.436)
- finished key points about resting potential (FITB handout)
- recapped key points about impulse transmission (FITB handout up to synapses)
- free time to begin work on "ticket to unit test"
We've discussed the basics of the NS and neurons, but it's evident that we have only dipped our toes into the HUGE complexity of the NS. Even by the end of the unit, you may remain a bit unsatisfied - but perhaps that will cause you to pursue further studies. Some interesting questions arose:
- why would a puncture wound (e.g. stabbing) hurt more than a punch?
- how might diet improve/harm the nervous system?
- why do burns hurt long after the stimulus is removed?
Also, it was noted that pain tolerance (threshold levels) vary from person to person. This shouldn't really be surprising, as almost every trait exhibits variation in most species. This aids in adaptation.
Above and beyond
I followed a comment string at: http://www.answerbag.com/q_view/1684038, which had many people's suggestions as to why burns continue to hurt beyond the initial stimulus. My thought was that the initial pain was due to the heat itself triggering surface pain receptors, but the continued pain was due to pain receptors responding to damaged cells.
One comment reminded me that there are many parallel sensory receptors acting simultaneously at any given time. Many simply fire due to a change in conditions (e.g. temp, pressure). These will stop firing when the changing condition stops - enabling you to acclimatize (i.e. stop feeling your clothes, or ignore "white" noise). Others respond to cell damage, and will continue to depolarize until the damage is repaired.
well done. Remember to include a summary of your findings. 3/3
ReplyDeleteMr. C