Chapter 12: Nervous System Final Flashcards
Two Subdivisions of the Nervous System
Central Nervous System
Peripheral Nervous System
Central Nervous System(CNS)
Brain and Spinal cord
Peripheral Nervous System(PNS)
Nerves and Gangila
Nervous System Process
Receive information
Transmit coded messages
Process information
Issue commands
Two Divisions of Nervous System
Sensory
Motor
Sensory Division
Somatic
Visceral
Motor Division
Effectors
Somatic
Universal Properties of Neurons
Excitability(irritability)
Conductivity
Secretion
Sensory Neurons
detect stimuli
Transmit information about them to CNS
begin in every organ in the body and end in CNS
Interneurons(association neurons)
lie entirely in CNS
Receive signals and carry out integrative functions
90%
Motor(efferent) neuron
send signals out to muscles and gland cells
Soma
control center of neuron
Dendrites
vast number of branches coming from a few thick branches from the soma
Axon(nerve fiber)
originates from a mound on one side of the soma
Multipolar Neuron
one axon and multiple dendrites
most in the brain and spinal cord
Bipolar Neuron
one axon and one dendrite
olfactory cells, retina, inner ear
Unipolar Neuron
single process leading away from the soma
sensory from skin and oran to spinal cord
Anaxonic Neuron
many dendrites but no axon
help in visual processes
Functions of glial cells
Support and Protect Neurons
bind neurons
Types of Neurongila that occur in the CNS
Oligodendrocytes
Ependymal cells
Microglia
Astrocytes
Types Occur in the PNS
Schwann Cells
Satellite Cells
Myelin Sheath and what it is formed by
insulating layer around a nerve fiber
formed by oligodendrocytes in CNS
Schwann cells in PNS
Local Potentials
distribution in membrane potential when a neuron is initially stimulated
Action Potential
more dramatic change produced by voltage-regulated ion gates in the plasma membrane
Refractory Period
the period of resistance to stimulation
Absolute refractory period
no stimulus- will trigger AP in Na gates are open
action potential to RMP
Relative Refractory Period
only especially strong stimulus will trigger new AP
Neural Integration
The ability of your neurons to process information , store and recall it, and make decisions
Excitatory postsynaptic potential (EPSP)
any voltage change in the direction of the threshold that makes a neuron more likely to fire
Inhibitory postsynaptic potential (IPSP)
any voltage change away from threshold that makes a neuron less likely to fire
Summation
the process of adding up postsynaptic potentials and responding to their net effect
Two types of Summation
Temporal
Spatial
Neural Coding
way the nervous system convert information to a pattern of action potential
Difference between Qualitative and Quantitative information
qualitative info based of which neurons fire
Quantitative info is about intensity of stimulus is encoded in two ways
Diverging Circuit
one nerve fiber branches and synapses with several postsynaptic cells
Converging Circuit
input from many different nerve fibers can be funneled to one neuron or neuron pool
Reverberating Circuits
neurons stimulate each other in linear sequence but one cell restimulates the first cell to start the process all over
Parallel after-discharge Circuits
input neuron diverges to stimulate several chains of neurons
Synaptic Plasticity
ability of synapses to change
Synaptic Potentiation
process of making transmission easier
Immediate Memory
ability to hold something in your thoughts for just a few seconds
Short-term memory
last from a few seconds to several hours
Long-term memory
last up a lifetime and is less limited in the amount of information it can store
Declarative Memory
retention of events and facts that you can put into words
Procedural Memory
Retention of motor skills