Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
|
______________ - what the membrane potential would have to be to keep ion X from moving across the membrane down its concentration gradient
|
the equilibrium potential for ion X
|
|
|
The equilibrium potential for an ion can be calculated using the __________ equation.
|
Nernst
|
|
|
What 3 things must be known to calculate the equilibrium potential for an ion?
|
1. the ion's intracellular concentration
2. the ion's extracellular concentration 3. the ion's charge (or valence) |
|
|
The Na⁺ equilibrium potential is typically about ________.
|
60 mV
|
|
|
The K⁺ equilibrium potential is typically about ________.
|
-88 mV
|
|
|
What happens to the membrane potential when channels for a specific ion open?
|
The membrane potential will move closer to the equilibrium potential for that ion.
|
|
|
What happens to the membrane potential when Na⁺ channels open?
|
The membrane depolarizes.
i.e. The membrane potential becomes more positive (moves toward the Na⁺ equilibrium potential). |
|
|
What happens to the membrane potential when K⁺ channels open?
|
The membrane hyperpolarizes.
i.e. The membrane potential becomes more negative (moves toward the K⁺ equilibrium potential). |
|
|
The membrane potential cannot be greater than ___________.
|
the Na⁺ equilibrium potential
|
|
|
The membrane potential cannot be less than _____________.
|
the K⁺ equilibrium potential
|
|
|
In a typical neuron, what regions receive signals from other neurons?
|
the dendrites and cell body (or soma)
|
|
|
___________ - another word for the cell body of a neuron
|
soma
|
|
|
____________ - a nerve impulse
|
action potential
|
|
|
Where in a typical neuron is a nerve impulse first generated?
|
at the axon hillock (or trigger zone)
|
|
|
Why can't action potentials be generated in the dendrites or cell body of a neuron?
|
The dendrites and cell body of a neuron do not have voltage-gated ion channels.
|
|
|
When the axon of a nerve cell is electrically insultated, we say the the nerve cell is ____________.
|
myelinated
|
|
|
When considering a synapse, the cell sending the signal is called the ___________ neuron.
|
presynaptic
|
|
|
When considering a synapse, the cell receiving the signal is called the ____________ cell.
|
postsynaptic
|
|
|
In what type of synapse are the presynaptic and postsynaptic cells connected by gap junctions?
|
electrical synapse
|
|
|
What is the advantage of electrical synapses?
|
faster conduction of the action potential across the synapse
|
|
|
What are the disadvantages of electrical synapses?
|
1. requires a lot of space
2. can only be excitatory (does not allow complex processing) |
|
|
_______________ - neurotransmitter receptors that are ligand-gated ion channels
|
inotropic receptors
|
|
|
______________ - neurotransmitter receptors that are G protein-coupled receptors
|
metabotropic receptors
|
|
|
If the membrane potential becomes less negative than the resting membrane potential, then the cell membrane is said to be ___________.
|
depolarized
|
|
|
If the membrane potential becomes more negative than the resting membrane potential, then the cell membrane is said to be _____________.
|
hyperpolarized
|
|
|
To illicit an action potential, the trigger zone of a neuron must be....
|
depolarized to threshold
|
|
|
What is an EPSP?
|
an excitatory post synaptic potential
(a depolarizing local potential) (a depolarizing graded potential) |
|
|
What is an IPSP?
|
an inbibitory post synaptic potential
(a hyperpolarizing local potential) (a hyperpolarizing graded potential) |
|
|
What are 2 other terms for a postsynaptic membrane potential?
|
local potential
graded potential |
|
|
Why do we say that a depolarizing postsynaptic potential is excitatory?
|
It will depolarize the trigger zone, taking it closer to threshold.
|
|
|
Why do we say that a hyperpolarizing postsynaptic potential is inhibitory?
|
It will hyperpolarize the trigger zone, taking it further from threshold.
|
|
|
If ligand-gated Na⁺ channels are opened, which is created?
an EPSP or IPSP? |
EPSP
(Na⁺ will pour into the cell, causing the membrane to depolarize.) |
|
|
If ligand-gated K⁺ channels are opened, which is created?
an EPSP or IPSP? |
IPSP
(K⁺ will pour out of the cell, causing the membrane to hyperpolarize.) |
|
|
Action potential or postsynaptic potential?
decays with distance |
postsynaptic potential
|
|
|
What causes the depolarization phase of the action potential?
|
open voltage-gated Na⁺ channels
|
|
|
What causes the repolarization phase of the action potential?
|
open voltage-gated K⁺ channels
|
