Term
| Signal transmission in a neuron is dependent on what two features? |
|
Definition
1. [ions] inside cell do NOT = [ions] outside the cell
2. Ion channels are selectively permeable to ions |
|
|
Term
| Can all cells generate an AP? |
|
Definition
| No, but all cells respond to electrical currents |
|
|
Term
| How does the lipid bilayer create capacitance? |
|
Definition
| Acts as an insulator and stores charge difference |
|
|
Term
| How do ion channels create conductance? |
|
Definition
| Allow charges to pass through the membrane |
|
|
Term
| What characterizes how readily charges can move across the plasma membrane? |
|
Definition
| Capacitance and conductance |
|
|
Term
| Conductance and capacitance are directly or inversely related? |
|
Definition
|
|
Term
|
Definition
| The current should change the membrane potential by an amount proportional to the resistance to current flow (dV=IR) |
|
|
Term
| What causes the delay in membrane potential? |
|
Definition
| Redistribution of charges slows the change in voltage on the membrane |
|
|
Term
| What limits how fast the voltage across the membrane can change? |
|
Definition
| Capacitance, which is influenced by the thickness of membrane |
|
|
Term
| What does thickness of membrane influence? |
|
Definition
|
|
Term
| What determines the level of capacitance? |
|
Definition
| Membrane thickness and the dielectric constant (reflects inherent ability of a membrane to hold charge based on fatty-acid make-up) |
|
|
Term
| Dielectric constant reflects... |
|
Definition
| The inherent ability of a membrane to hold charge based on fatty-acid make-up |
|
|
Term
| Why does a signal decay with distance? |
|
Definition
| Cytoplasm has resistance to the flow of electrical signals and some charges leak out of the cell across the membrane and then don't contribute to current flow |
|
|
Term
|
Definition
| Electromotive force that occurs at the steady state (electrochemical equilibrium) |
|
|
Term
|
Definition
| A potential difference across the membrane that is established via an electrochemical gradient |
|
|
Term
| Once equilibrium is reached... |
|
Definition
| No further net flux of ions across the membrane |
|
|
Term
| As the concentration gradient on an ion increases, BLANK also increases |
|
Definition
|
|
Term
| A larger chemical gradient requires a greater BLANK to offset the increased tendency for the ion to diffuse down its concentration gradient |
|
Definition
| Electrical potential difference |
|
|
Term
| The Nernst equation solves for... |
|
Definition
| The equilibrium potential of single ions |
|
|
Term
| At a steady state, what is happening to Na+? |
|
Definition
| Na+ leaks into the cell slowly and is actively pumped out |
|
|
Term
| At a steady state, what is happening to K+? |
|
Definition
| K+ leaks out slowly and is actively pumped in |
|
|
Term
| Na/K ATPase pump pumps what in and what out? |
|
Definition
|
|
Term
| What governs resting potential? |
|
Definition
| Presence of open ion channels, unequal distribution of ions and charge of the ions |
|
|
Term
| Goldman equation calculates... |
|
Definition
|
|
Term
| Signal transmission in a neuron is dependent on what two features? |
|
Definition
1. [ions] inside cell do NOT = [ions] outside the cell
2. Ion channels are selectively permeable to ions |
|
|
Term
| Can all cells generate an AP? |
|
Definition
| No, but all cells respond to electrical currents |
|
|
Term
| How does the lipid bilayer create capacitance? |
|
Definition
| Acts as an insulator and stores charge difference |
|
|
Term
| How do ion channels create conductance? |
|
Definition
| Allow charges to pass through the membrane |
|
|
Term
| What characterizes how readily charges can move across the plasma membrane? |
|
Definition
| Capacitance and conductance |
|
|
Term
| Conductance and capacitance are directly or inversely related? |
|
Definition
|
|
Term
|
Definition
| The current should change the membrane potential by an amount proportional to the resistance to current flow (dV=IR) |
|
|
Term
| What causes the delay in membrane potential? |
|
Definition
| Redistribution of charges slows the change in voltage on the membrane |
|
|
Term
| What limits how fast the voltage across the membrane can change? |
|
Definition
| Capacitance, which is influenced by the thickness of membrane |
|
|
Term
| What does thickness of membrane influence? |
|
Definition
|
|
Term
| What determines the level of capacitance? |
|
Definition
| Membrane thickness and the dielectric constant (reflects inherent ability of a membrane to hold charge based on fatty-acid make-up) |
|
|
Term
| Dielectric constant reflects... |
|
Definition
| The inherent ability of a membrane to hold charge based on fatty-acid make-up |
|
|
Term
| Why does a signal decay with distance? |
|
Definition
| Cytoplasm has resistance to the flow of electrical signals and some charges leak out of the cell across the membrane and then don't contribute to current flow |
|
|
Term
|
Definition
| Electromotive force that occurs at the steady state (electrochemical equilibrium) |
|
|
Term
|
Definition
| A potential difference across the membrane that is established via an electrochemical gradient |
|
|
Term
| Once equilibrium is reached... |
|
Definition
| No further net flux of ions across the membrane |
|
|
Term
| As the concentration gradient on an ion increases, BLANK also increases |
|
Definition
|
|
Term
| A larger chemical gradient requires a greater BLANK to offset the increased tendency for the ion to diffuse down its concentration gradient |
|
Definition
| Electrical potential difference |
|
|
Term
| The Nernst equation solves for... |
|
Definition
| The equilibrium potential of single ions |
|
|
Term
| At a steady state, what is happening to Na+? |
|
Definition
| Na+ leaks into the cell slowly and is actively pumped out |
|
|
Term
| At a steady state, what is happening to K+? |
|
Definition
| K+ leaks out slowly and is actively pumped in |
|
|
Term
| Na/K ATPase pump pumps what in and what out? |
|
Definition
|
|
Term
| What governs resting potential? |
|
Definition
| Presence of open ion channels, unequal distribution of ions and charge of the ions |
|
|
Term
| Goldman equation calculates... |
|
Definition
|
|
Term
| Resting potential is most sensitive to BLANK |
|
Definition
|
|
Term
| What role does active transport have on resting potential? |
|
Definition
| Increases emf by maintaining Vrest as negative |
|
|
Term
|
Definition
|
|
Term
| What are more abundant? Neurons or supportive cells |
|
Definition
|
|
Term
| Electrotonic conduction is influenced by capacitance or conductance? |
|
Definition
|
|
Term
| Electrotonic conduction depends on |
|
Definition
| Movement of ions along the two faces of the plasma membrane (physical properties) |
|
|
Term
| Regenerative conduction depends on |
|
Definition
| Presence and activity of voltage-gated channels (movement of ions) |
|
|
Term
| Regenerative conduction depends on capacitance or conduction? |
|
Definition
|
|
Term
| What determines stimulus strength in a graded signal? |
|
Definition
|
|
Term
| What does a NT bind to on a dendrite? |
|
Definition
|
|
Term
| What integrates the multiple signals received via the dendrites? |
|
Definition
| Spike-initiating zone located at the axon hillock |
|
|
Term
| What determines if a neuron will initiate its own signal? |
|
Definition
|
|
Term
| Production of AP is dependent upon... |
|
Definition
| Asymmetric [ions], electrochemical gradient, and change in Vm |
|
|
Term
|
Definition
| Momentary reversal of membrane potential from -65mV to 45mV on the inside of the cell |
|
|
