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Ch 2 (NC) Ward 3rd
The Student's Guide to Cognitive Neuroscience
Question | Answer |
---|---|
What are the main structures of a Neuron? | Dendrites, Soma, Nucleus, Axon Hillock, Axon, Myelin, Nodes of Ranvier, Synaptic Terminals |
What is Resting Potential? | Resting potential is the state of equilibrium of both electrical charge and concentration gradient that puts a cell in an optimal state to quickly respond. |
What is Action Potential? | The excitation of a neuron that produces electrical firing down the axon. |
Describe the importance of the Refractory Period. | The Refractory Period allows the cell to reset before producing new Action Potentials and prevents Action Potentials from reversing direction. |
What is Synaptic Potential? | Synaptic Potential is the difference in charge between the inside and outside of a postsynaptic neuron. |
The mV of a neuron reads at +50 on a single cell recording. What phase of an Action Potential is this? | This is the depolarization phase (positive charge) of an Action Potential. |
The mV of a neuron reads at -90 on a single cell recording. What phase of an Action Potential is this? | This is the refractory phase (overly negative charge) of an Action Potential. |
The mV of a cell reads at 0 on a single cell recoding. What two phase of an Action Potential could this be? What is happening to the ions of the cell for each phase? | This could be the Depolarization phase or Repolarization phase. During the Depolarization phase, sodium (Na+) is quickly entering the cell, making the electrical charge more positive. (Rising charge) During the Repolarization phase, potassium (K+) |
What is the difference between Absolute and Relative Refractory Periods? | During the Absolute Refractory Period the electrical charge of a cell is continuing to fall and a new Action Potential is unable to be produced. During the Relative Refractory Period the electrical charge of a cell is staring to rise and a new Action P |
A single cell recording shows a small decrease in the polarity of a cell (the recording becomes more positive), but an Action Potential does not fire. Why? | You didn't cross me threshold. |
What does myelin do for a neuron? | Myelin insulates the axon and prevents "leak" (the deterioration of an Action Potential signal) down the length of the the axon, allowing the Action Potential to go farther in the body than it would be able to travel without myelin. |
I am a lipid bilayer that will allow some ions in and some ions out. I am choosy about what ions may enter and leave, and when. What am I? | A selectively permeable membrane. |
What two types of cells make up the nervous system? | Neurons and Glia |
What are two systems are parts of the nervous system? | The peripheral nervous system and the central nervous system. |
How many axons are on a typical neuron? | ONE! |
What does a Dendrite do? | The dendrites on a postsynaptic cell receive information from a presynaptic cell. |
What does an Axon Terminal do? | Prepares information to be sent from the presynaptic cell to the postsynaptic cell. |
Why is an Axon important? | Because there is typically only one. It is difficult to regrow an axon. Even if an axon can be regrown, it grows back very slowly and it can be very long, which means it can take a long time to regrow. |
If I am looking at a cell and I notice that there are negative ions on the inside and positive ions on the outside, and that the cell is polarized, what am I seeing? | An electrical gradient. |
If I am looking at a cell and I notice that there are Na+ ions on the outside and K+ ions on the inside, what am I seeing? | A concentration gradient. |
Why is an action potential like flushing a toilet? | Because it is all or nothing and the refractory period must be complete before a new Action Potential can occur. |
The mV of a cell reads at -70 on a single cell recording. What phase of an Action Potential is this? | This is the resting potential phase. |
The mV of a cell reads at -30 on a single cell recording. What phase of an Action Potential is this? | This could be the depolarization phase or the repolarization phase. |