Membrane and resting potential
What does membrane potential describe?
The difference in electrical charge across a plasma membrane
What is the resting membrane potential listed in the PowerPoint?
−70 mV
What type of Na⁺ channel is associated with a graded potential?
Ligand-gated Na⁺ channel
Where does the PowerPoint associate voltage-gated Na⁺ channels with the neuron?
Axon hillock
What is the small gap between one neuron and another called?
Synaptic cleft
What unit is used to measure membrane potential?
Millivolts (mV)
What is it called when the inside of the membrane becomes less negative?
Depolarization
What happens to graded potentials as they travel?
They decay
What are the two types of action potential conduction listed in the PowerPoint?
Continuous conduction and saltatory conduction
At a neural synapse, an electrical signal needs to be transferred into what type of signal?
A chemical signal
At resting membrane potential, which ion has a higher concentration outside the cell?
Sodium (Na⁺)
During depolarization, which direction does the graph deflect
Upward
Graded potentials are compared to what type of signal?
An analog signal
What type of conduction is specifically called “continuous”?
Continuous conduction
What structure separates one neuron from another at a neural synapse?
The synaptic cleft
At resting membrane potential, which ion has a higher concentration inside the cell?
Potassium (K⁺)
What is it called when the inside of the membrane becomes more negative and the graph returns to resting?
Repolarization
What happens when a graded potential is subthreshold at the trigger zone?
An action potential is not generated
What type of conduction is specifically called “saltatory”?
Saltatory conduction
What two forms of signaling are involved in neural synaptic transmission according to the PowerPoint?
Electrical and chemical signaling
What two ions have leak channels that contribute to the resting membrane potential?
Potassium (K⁺) and sodium (Na⁺)
What is it called when the membrane becomes more negative than resting?
Hyperpolarization
What two terms describe an action potential according to the PowerPoint?
All-or-none and a digital signal (0 or 1)
During a refractory period, why can an action potential not be generated?
Ion channels remain closed
In which direction does the signal conversion described on the neural synapse slide occur?
Electrical signal to chemical signal