Neural Conduction Flashcards
Be a bad motherfucker on that action potential tip
the diff between internal and external charge of a neuron
membrane potential
how to measure membrane potentia?
microelectrode
One tip inside and other in the extracelluar fluid
inside charge of neuron is
-70mV
Na+ is
Sodium
Potassium is
K+
At rest there is are more ___outside and more ___ inside
Na+
K+
what creates pressure for Na+ to enter a neuron?
the electrostatic pressure from the Resting Membrane Potential due opposite charges attracting
AND
random motion
What is the function of the sodium/potassium pump?
Maintains membrane potential
what is the ratio of action for the Sodium Potassium pump?
3 Na+ out
2 K+ In
input from another cells results in
Post-synaptic potentials
What are the two possible effects when NTs bind to Post-syn-receptors?
Depolarize (excitatory PSP)
Hyperpolarize (inhibitory PSP)
all post-syn-potentials are
graded potentials
Amplitudes are proportional to the signals that elicit them
what amplitude is the Threshold of Excitation?
about 65mV
Action potentials are
all or nothing
Explain Spatial summation of an EPSP or IPSP
two simultaneous EPSP or IPSP will produce a greater -one
simultaneous IPSP and EPSP will cancel each other out
Explain temporal summation of EPSP and IPSP
Rapid succession of IP or EP can add up to a bigger one
PSP’s can outlast and superimpose on the next one.
Tremor at rest is a symptom of
Parkinson’s
A neuron is rest is said to be
polarized
What are the two factors that pressure Na+ ions to enter resting neurons?
random motion
electrostatic pressure
at rest, neurons have more _____ outside than inside
Na+
Rising phase of AP?
Na+ channels open and ions rush in
K+ channels open and K+ ions leave
Once MP is depolarized, the Na+ channels close
Repolarization Phase of AP
K+ channels stay open and ions keep leaving until -70mV is achieved.
Hyperpolarization Phase of AP
K+ channels stay open and the MP gets to -90mV
how long is the refractory period of an AP and what can’t happen?
1-2ms
Absolute refractory
Can’t fire again
Relative refractory?
a neuron can fire again, but stim needs to be higher than normal.
Transmission in myelinated axons is
saltatory conduction
neurons are about ___ apart
20 nanometers
3 types of ion transporters
Pumps (in and out) (atp energy)
Co-transporters (use energy from diffusion)
Exchangers (energy from diffusion)
most ion channels are of two types….
Voltage (open close due to changes in polarization)
Lingand (open due to binding of NT or Neuromodulator to receptor associated with the channel)
