Chapters 4 and 5: Electrical Activity of Neurons and the Communication Between Neurons Flashcards
Which ions are more concentrated in the intracellular fluid when a neuron is at rest?
A- and K+
Which ions are more concentrated in the extracellular fluid when a neuron is at rest?
Sodium Chloride (NaCl)
What is the membrane potential (the electrical charge) of the neuron when it is at rest? In other words, what is the resting potential?
-70 mV
What is the threshold potential (the electrical charge) that triggers the action potential?
-50 mV. This is also when voltage-sensitive K+ and Na+ channels open.
In EPSP (Excitatory Postsynaptic Potential), which ion plays the most important role?
Sodium (Na+)
At the level of the terminal button, which ion is the most important one for the release of neurotransmitters?
Calcium (Ca+)
What are channels?
One of the ways in which ions can enter a neuron. They allow only specific ions to enter and leave the neurons.
What are pumps?
They transport substances and ions such as the Na+ K+ pump. This is another way that ions can enter a neuron.
What are gates?
Channels. but gated 😏. The gates either open or close.
When a membrane is depolarizing it becomes…
Less negative!
The synapse includes the…
presynaptic membrane
Synaptic cleft
postsynaptic membrane
What does the cell body (soma) do?
Keeps the neuron alive and determines whether a neuron will fire or not.
What do the dendrites do?
They receive information from other neurons and transport it to the cell body.
What does the axon do?
It is an extending fiber that conducts impulses away from the cell body and transmits it to other cells.
What is the synapse?
The site where a nerve impulse goes from one cell to another. It includes the axon terminal, the synaptic cleft, and the receptor sites of the postsynaptic neuron.
