Neurons Flashcards
Basic unit of the nervous system
Neuron
Extensions of the cell body that is connected to other neurons and takes information in the form of neurotransmitters
Dendrites
Long tube where information is transmitted
Axon
Where information begins
Axon hillock
Schwann cell insulators wraped throughout axon
Myelin sheaths
Gap between neurons where information is exchanged
Synapse
Structural classification of a neuron that has multiple poles and is the most common
Multipolar
Structural classification of a neuron that has two poles and is very rare
Bipolar
Structural classification of a neuron with a single pole and serves as a sensory neuron
Unipolar
Structural classification of a neuron that is primarily found in the brain
Anaxonic
Functional classification of a neuron that brings information in through receptors
Sensory or afferent
Functional classification of a neuron that sends information to effectors
Motor or efferent
Processes and integrates information
Cell body
Transmits information to next cell
Axon terminal
Bundle of axons travelling together
Nerve
If the stimulation the dendrites receive is strong enough, the signal is transmitted along the entire length of the axon
Action potential
Threshold voltage of an action potential
-55 millivolts
What happens when the neuron is at rest?
Concentration of sodium ions is HIGHER OUTSIDE than inside, and potassium ions HIGHER INSIDE than outside.
What does the ionic separation at the cell membrane create?
Chemical gradient
The difference in charge across the membrane where there are more positively charged ions outside than inside of the cell.
Electrical gradient
The ionic imbalance between the chemical and electrical gradient
Electrochemical gradient
Difference in total charge inside and outside the cell
Membrane potential
Neuronal membrane at rest’s potential, where the inside of the cell is _____________ less positive than the outside
-70 millivolts
When the cell has achieved electrochemical equilibrium
Resting-membrane potential
