neurons and synaptic transmission Flashcards
What is a neuron?
the basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals
what are sensory neurons?
these carry messages from the PNS to the CNS. they have long dendrites and short axons
what are relay neurons?
these connect the sensory neurons to the motor or other relay neurons. they have short dendrites and short axons
what are motor neurons?
these connect the CNS to effectors such as muscles and glands. they have short dendrites and long axons.
draw a diagram of the 3 neurons
what does the cell body (soma) include?
a nucleus, which contains the generic material of the cell
what do dendrites do?
protrude from the cell body, they cary neural impulses from neighbouring neurons towards the cell body
what does the axon do?
carries impulses away from the cell body down the length of the neuron
what does the myelin sheath do?
covers the axon, protecting it, and speeds up electrical transmission of the impulse
what is the function of the nodes of ranvier?
they speed up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon
what do the terminal buttons do?
they are located at the end of the axon and communicate with the next neuron in the chain across a gap known as the synapse
when a neuron is resting what is the charge of the inside?
it’s negatively charged compared to the outside
what happens to a neuron when it is activated by a stimulus?
the inside of the cell becomes positively charged for a split second causing an action potential to occur. this creates an electrical impulse that travels down the axon towards the end of the neuron
signals within neurons are transmitted..
electrically
signals between neurons are transmitted…
chemically across the synapse