Neuronal Signaling 4.2.3 Flashcards
What are action potentials ?
What is the axon?
Longer extension that transmits signals to neurons or other target cells
What are dendrites?
Branched extension that receive signals from other neurons
What is depolarization?
A decrease in the magnitude of the membrane potential
What are gated ion channels?
A special type of protein channel that opens or closes in response to specific stimuli that can be chemical or electrical
-the reason why changes in membrane occur
What are graded potentials?
Changes in polarization where the magnitude of the change varies with the strength of the stimulus
-small changes to membrane potential
What is hyperpolarization?
An increase in the magnitude of the membrane potential
What is a ligand-gated ion channel?
A channel that opens or closes in response to the chemical binding of specific ligands
What is a myelin sheath?
layer of electrical insulation that surrounds vertebrate axons.
What are nodes of Ranvier?
What is the refractory period?
What is the saltatory conduction?
What is the soma?
Cell body or main body section of a neuron
What is the synaptic terminal?
Transmit information to another cell at a junction called a synapses
What is the voltage-gated ion channel?
Opens or closes in response to the changes in membrane potential
What is a synapse?
Short gap between two neighboring neuron where information can be passed
-chemical signals
What type of signals do neurons have?
Long-distance electrical signals and short-distance chemical signals
What is the rising phase in active potential?
Increased depolarization causes more sodium channels to open, leading to an even greater flow of current
-results in positive feedback
What is the falling phase in active potential?
When the membrane potential rises to a specific value, voltage-gated sodium channels become inactivated and close. However, voltage-gated potassium channels open, and potassium ions begin flowing out of the cell.
-lowers membrane potential, creating a negative feedback loop (restore to resting state
