Nerve Communucation Flashcards
Action potentials are _____ distance communication
Long
What is the normal resting potential in mV?
-70 mV
3 Na ions go out for every…
2K ions that come into the cell
What is the electrochemical gradient?
The main path for current to flow across a membrane
Graded potentials are ______ distance communication
Short
Graded potentials are either more or less_______
Polarized
Where do most graded potentials occur?
The soma and dendrites
What does graded mean?
Amplitude of electrical signal varies
What do amplitude of electrical signals vary on?
Strength of stimulus
Number of ligand gated or mechanical geted channels open
What do action potentials propagate along?
Axons
What are action potentials only in?
Excitable membranes (neuron and muscle cells)
Action potentials don’t_______ with distance
Decrease
What is the resting state of an axon potential?
Voltage gated ion channels open
What is depolarization?
The membrane potential becomes less negative reaching zero
What must the action potential reach to get to depolarization?
Threshold(-55mV)
What is repolarization?
Sodium channels close and potassium channels open
Membrane potential is restored to its resting state
What is hyperpolarization?
Some potassium channels open and sodium channels reset
What factors affect the speed of an action potential?
The amount of Myelination
Axon diameter
Temperature
What are the two types of synapses?
Electrical and chemical
What is a synapse?
Junction between neurons the action potentials travel through
What does the presynaptic neuron do?
Sends a signal
What does the postsynaptic neuron do?
Receives the signal
Is an electrical synapse passive or active transport?
Passive
What direction does the current flow in an electrical synapse?
In both directions
What do chemical synapses do?
Convert electrical signals (action potential) to chemical signals ( neurotransmitter)
