Lecture 2 Flashcards
in neurons, the Resting Membrane Potential is b/w ___ and ___
-60 to -70mV
The action potential allows for the communication of information at a much more _____ pace than convection or diffusion
rapid
What are the 3 ions in the body that are important in the neurons of humans. they play and active role in the electric capabilities of the system and are important components influencing neural communication.
Na+
K+
Cl-
Sodium is more concentrated (inside or outside)
outside
potassium is more concentrated (inside or outside)
inside
Chloride is more concentrated (inside or outside)
inside
a membrane may be considered a________ this means it can store an electric charge or potential, which will allow it to spread.
capacitor
the dispersion of an electric signal
action potential
A small stimulus leads to a small response.
A medium stimulus leads to a medium response.
A large stimulus leads to a large response. what does this mean
the AP will always be the same, the response refers to the amount and frequency of APs.
An action potential only occurs when the stimulus is strong enough to _________ the membrane beyond the membrane potential
depolarize
either the membrane does not generate an AP or it generates and AP with a standard shape and magnitude
All or none Law
a negative movement of the membrane potential
hyperpolarization
during hyperpolarization, ______ moves _____
K+ moves out
a positive shift in the membrane potential
depolarization
during depolarization ______ moves ___
Na+ moves in
what happens to the MP during depolarization and hyperpolarization?
depolarization: becomes more positive (Na+ come in)
hyperpolarization: becomes more negative (K+ goes out)
would a large intensity stimulus, such as stepping on a sharp object, cause a larger AP to be generated?
No, it would only cause a greater frequency of AP
the period following the generation of an AP in which it is not possible to generate a new AP
absolute refractory period
the period followin the generation of an action potential in which it is possibl to generate another action potential. the second action potential may not be generated with the same intensity of stimulus. An increase in intensity is necessary to generate a new AP
relative refractory period
______ feedback leads to a rapid amplification of the effect
positive
______ feedback quickly restores the original state
negative
depolarization is ______ feedback
positive
hyperpolarization is _______ feedback
negative
examples of positive feedback
running, then you speed up
example of negative feedback
running, have to slow down bc you can to an intersection
How do Na+ channels open and close?
they open quickly, but close quickly too
How do K+ channels open and close
they open slower, and remain open longer
4 important properties of APs for neural signaling
- APs have a threshold for initiation (-50 mV) at which an AP is generated
- The AP is an All or None movement.
- The AP is conducted w/o decrement. It is self regenerative, which keeps AP constant
- the AP is followed by a refractory period.
