Neurons & The Action-Potential Flashcards
What type of signals do neurons use in their activity?
Both electrical and chemical signals
How do neurons cooperate and compete?
They regulate the overall state of the nervous system
What is the basic structure of a neuron?
Dendrites, cell body, axon, and synaptic terminals
What is the function of dendrites?
To receive signals from other neurons
What does the cell body of a neuron do?
Integrates signals
What is the role of axons in a neuron?
Transmits signals to other neurons
What is meant by the term ‘polarization’ in neurons?
Information processing goes in only one direction
What are dendritic spines?
Tiny protuberances on dendrites where synapses are located
What do mitochondria do in neurons?
Provide energy for neuronal activity
What are growth factors?
Molecules that influence neuronal gene expression and protein manufacture
What is synaptic transmission?
Communication between nerve cells at synapses
What happens when a dendrite receives a chemical messenger?
Miniature electrical currents are set up inside the dendritic spine
What are the two types of currents that can occur in a neuron?
Excitation and inhibition
What is an action potential?
An electrical pulse that travels along the axon
How do ion channels contribute to action potentials?
They open to allow Na+ and K+ ions to flow in and out of the cell
What is the voltage change during an action potential?
Flips from about -70 mV to +30 mV
What happens during the refractory period?
The membrane recovers its capability for the next action potential
What is the myelin sheath?
A fatty insulating blanket around some axons
How does the myelin sheath affect action potentials?
It prevents ionic currents from leaking and allows faster transmission
What is the characteristic of action potentials?
They are all-or-nothing events
What is the maximum frequency of action potentials in efficient axons?
Up to 1000 times per second
Who won the Nobel Prize for discovering the mechanism of nerve impulse transmission?
Alan Hodgkin and Andrew Huxley
Fill in the blank: Neurons both cooperate and ______ with each other.
compete
Fill in the blank: The outer membranes of neurons are made of ______ substances.
fatty
True or False: Dendritic spines are where most synapses are located.
True
Fill in the blank: The axons of neurons transmit electrical pulses called ______.
action potentials
What do ion pumps do in neurons?
Maintain balance of Na+ and K+ ions
