neurons and synaptic transmission Flashcards
(21 cards)
what do neurons do
transmit electrical and chemical signals to provide the ns with its primary means of communication
list the types of neurons
motor, sensory, relay
list the structures of a neuron
cell body, nucleus, dendrites, axon, myelin sheath, terminal buttons
what is inside the cell body
the nucleus
what are dendrites
branch like structures protruding from the cell body, carrying nerve impulses from neighbouring neurons towards the cell body
what does the axon do
carries impulses away from the cell body
what are terminal buttons
connect with the next neuron across the synapse
what is the myelin sheath
fatty layer that protects the axon and speeds up the electrical impulse, gaps called nodes of Ranvier which force the impulse to jump across
describe the function and structure of sensory neurons
carry messages from the pns to the cns
long dendrites and short axons
describe the function and structure of relay neurons
connect the sensory neurons to motor or other relay neurons
long dendrites and short axons
describe the function and structure of motor neurons
connect the cns to effectors such as muscles and glands
short dendrites and long axons
what happens when a neuron is in a resting state
the inside of the cell is negatively charged compared to the outside
what happens when a neuron is activated by a stimulus
the inside of the cell becomes positively charged for a split second causing an action potential to occur
what happens when an action potential occurs
an electrical impulse is created that travels down the axon towards the end of the neuron
neurons communicate with each other within groups known as what
neural networks
when are signals between neurons transmitted chemically and electrically
within neurons are electrical and between neurons are chemical across the synapse
what happens when the electrical impulse reaches the end of the neuron
triggers the release of neurotransmitters from tiny sacs called synaptic vesicles
what are neurotransmitters
chemicals that diffuse across the synapse to the next neuron in the chain
what are neurotransmitters taken up by
the postsynaptic receptor site (dendrites of the next neuron)
how does serotonin cause an inhibitory effect on the next neuron
the neuron becomes negatively charged and is less likely to fire
how does adrenaline cause an excitatory effect on the next neuron
increasing its positive charge and making it more likely to fire
