NEURONS AND SYNAPTIC TRANSMISSION Flashcards
what % of neurons are located in the brain?
80%
what do neurons do?
they transmit signals electrically and chemically
what are the three types of neurons?
sensory
relay
motor
what are sensory neurons?
messages from the PNS t the CNS
how are snesory neurons adpted for ther function?
long dendrites and short axons
what are relay neurons?
connect the sensory neurons to motor or other neruons
how are relay neurons adapted for their function?
short dendrites
short axons
what are motor neurons?
connect CNS to effectors e.g. muscles or glands
how are motor neurons adpted for their function?
short dendrites
long axons
what is the basic structure of a neuron?
- cell body with nucleus
- dendrites extending from body carrying nerves impulses away from neighbouring neurons to cell body
- axon carrying impulse away from cell body down neuron
- axon covered w/ myelin sheath protect axon and speed up elec impulse
- nodes of ranvier ensure that impulses have speed as it is a gap
- terminal buttons communicate with next neuron across synapse
what is step 1 in the structure of a neuron?
1.cell body with nuclues
what is step 2 in the structure of the neuron?
dendrites carry nerve impulses away from neighbouring neurons to cell body
what is step 3 in the structure of a neuron?
axon carrying impulse away from cell body down neuron
what is step 4 in the structure of a neuron?
axon covered w/ myelin sheath protect axon and speed up elec impulse
what is step 5 in the structure of a neuron?
nodes of ranvier ensure that impulses have speed as it is a gap