biopsych; neurons and synaptic transmission - Y12 Flashcards
how are signals transmitted?
how are signals transmitted?
what is a neuron?
the basic building blocks of the nervous system, neurone are nerve cells that process and transmit messages through electrical and chemical signals
what is a sensory neuron?
these carry messages from the PNS to the CNS which long dendrites and short axons
what is a relay neuron?
these connect the sensory neurons. to the motor or other relay neurons. they have short dendrites and short axons
what is a motor neuron?
these connect the CNS to the effectors sun as muscles and glands. they have short dendrites and long axons
what does EPSP stand for
excitatory postsynaptic potential
what does IPSP stand for
inhibitory postsynaptic potential
what do dendrites do?
carry nerve impulses from the adjacent neurons towards the cell body
what is the soma?
the cell body that includes a nucleus which contains the genetic material of the cell
what does the axon do?
carries the impulses away from the cell body down the length of the neuron
what is the myelin sheath?
a fatty substance that covers and protects the axon and speeds up electrical transmission of the impulse.
what are the Nodes of Ranvier?
gaps between the myelin sheath which speed up the transmission by forcing them to jump across the gap.
what is the terminal button?
the bottom of the axon which is where the neuron communicates with the postsynaptic neuron through the synaptic cleft.
what is electrical transmission?
when the neuron is activated by the stimulus, the inside of the cell becomes positively charged causing action potential to occur which creates an electrical impulse to travel down the axon towards the end of a neuron.
what is synaptic transmission?
the process by which neighbouring neurons communicate with each other by sending chemical messages across the gap which separates them.
what is a neurotransmitter?
brain chemicals which are released from synaptic vesicles that relay signals across the synapse from one neuron to another. they can be divided into excitatory or inhibitory neurotransmitters
what is excitation?
when a neurotransmitter increases the positive charge of the neuron making it more likely to fire and pass on the impulse
what is inhibitory?
when a neurotransmitter increases the negative charge of the neuron making it less likely to fire and pass on the impulse
how are signals transmitted electrically?
signals WITHIN neurons are transmitter electrically
how are signals transmitted chemically?
signals BETWEEN neurons are transmitted chemically across the synapse
what is summation?
is the process that determines whether or not an acton potential will be triggered by the combined effects off epsp and ipsp.
