PNB 2XB3 - Neuroanatomy &
Neurophysiology Questions and
Answers |100% Pass
How many neurons are in the human brain? - Answer-about 100 billion
What percentage of the brain do we use? - Answer-100%
What is the brain's power in watts? - Answer-20 W
What is the size of a typical neuron? - Answer...
Voltage gated K+ channels open - K+ rushes out - Hyperpolarization occurs
3 States of the voltage gated sodium channel - Answer✔✔-Closed, Open, Inactivated
Action Potential Summary - Answer✔✔-1. Membrane is depolarized past threshold
by a receptor or synaptic potential
2. Voltage gated sodium channels open in a positive feedback loop, causing rise
3. The sodium channels inactivate, ending the rising phase and initiating the refractory
period
4. Voltage gated potassium channels open causing the falling phase and the
undershoot (afterhyperpolarization: AHP)
5. The sodium channels close, ending the refractory period
6. The potassium channels close, ending the undershoot and restoring the membrane
to it's resting potential
Refractory - Answer✔✔-Inability to continue
Benefits of the refractory period - Answer✔✔-Ensures unidirectional action potential
conduction, away from the point of origin
Consequences of the refractory period - Answer✔✔-places an upper limit on the firing
rate of a neuron (bad thing)
4/51
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller EmillyCharlotte. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.
