neurons Flashcards
neurons?
nerve cells
sensory neuron?
detects sense info and carries from PNS to the CNS(long dendrites and short axons)
relay neuron?
connect sensory neurons to motor neurons - do not connect directly - also connect to other relay neurons - short dendrites and short axons
motor neurons?
carries electrical signal to the effector - short dendrites and long axons
dendrites?
stick out of the cell body
cell body?
includes nucleus (genetic info) - these carry electrical signals from other neurons to the cell body
axon?
away from the cell body and down the length of the neuron - covered in a fatty layer called the myelin sheath
myelin sheath?
protects axon - speeds up electrical signals - gaps called nodes of ranvier - makes signal go even faster
terminal buttons?
end of the axon which communicate to the next neuron across the synaptic cleft
how neurons fire?
resting state - negative charge - neuron changes for a split second - creates electrical signal that is carried to the axon at the end of the neuron
synaptic transmission?
neighbouring neurons communicating with each other
what is the synapse made up of?
synaptic cleft (space between the neurons), end of one neuron (presynaptic neuron) , start of another neuron(post synaptic neuron)
neurotransmitter?
chemical that is released from the synaptic vesicles, send signals by the synaptic cleft from one neuron to another
what happens when an electrical signal reaches the end of a neuron?
arrives at terminal button, tiny sacs called vesicles, contain neurotransmitters, electrical signals cause them to release neurotransmitter molecules, travel across synaptic cleft to the next neuron
what happens if there is any neurotransmitters left in the gap?
broken down by enzymes and reabsorbed at the presynaptic neuron
