neuroscience Flashcards
Distinctive feature of neurons
Ability to communicate with other cells
Transmission of information across relatively long distances
Myelin sheath
Improves the efficiency of neural transmissions
Also called the white matter
Only found in nervous system of higher animals
Damage to myelin sheath can be tragic and severe
Resting stat
State in which there is a negative electrical charge of about −70 millivolts within a neuron
Action potential
Electric nerve impulse that travels through a neuron’s axon when it is set off by a “trigger”
Positive electrical charge of about +40 millivolts within a neuron
Speed at which an action potential travels along an axon is determined by the:
Axon’s size
Thickness of the myelin sheath
Neurons differ in terms of:
Quickness of an impulse moving along the axon
Potential rate of firing
Excitatory message:
a chemical message that makes it more likely that a receiving neuron will fire and an action potential will travel down its axon.
Inhibitory message
a chemical message that prevents or decreases the likelihood that a receiving neuron will fire.
synthesis:
transmitter molecules are formed inside the neuron
storage
transmitter molecules are stored in synaptic vesicles which are chambers within axon terminals.
release
When released form presynaptic (sending) neuron, transmitter molecules move from synaptic vesicles across the gap
binding
transmitter molecules bind themselves to receptor sites in the postsynaptic (receiving) neuron
transmitter molecules bind themselves to receptor sites in the postsynaptic (receiving) neuron
Receiving neurons awash, in a continual chemical bath
Producing constant stimulation or constant inhibition of the receiving neurons
Effective communication across the synapse would no longer be possible
Reuptake
Reabsorption of neurotransmitters by a terminal button
Spinal cord:
Bundle of neurons that leaves the brain and runs down the length of the back
Main means for transmitting messages between the brain and the body
Controls simple behaviors on its own, without any help from the brain