Neurons and synaptic transmission Flashcards
What is the function of sensory neurons?
Carry nerve impulses from sensory receptors to the CNS
What is the function of relay neurons?
Connect sensory and motor neurons, and are found in the CNS. They are also known as interneurons
What is the function of motor neurons?
They have long axons which carry nerve impulses to muscles, triggering muscle contraction
What does the nerve impulse do?
It travels along the axon in the form of an electrical signal called action potential
What helps nerve impulses cross the synaptic gap?
neurotransmitters
The arrival of an ______ _________ at the end of the axon triggers the release of neurotransmitter molecules from synaptic vesicles into the synaptic gap
action potential
What is the process called when neurotransmitter molecules are released into the synaptic gap from synaptic vesicles?
exocytosis
After exocytosis, neurotransmitter molecules diffuse across the gap and bind to (1)__________ _________ in the membrane of the post-synaptic neuron, where they trigger a new (2)______ _________
(1) specialised receptors
(2) action potential
Excitatory neurotransmitters cause an __________ ____-_______ ________ (EPSP), making the postsynaptic neuron more likely to fire
excitatory post-synaptic potential
Name 2 examples of excitatory neurotransmitters
acetylcholine
noradrenaline
Inhibatory neurotransmitters cause an _________ ____-________ _________ (IPSP), making the post-synaptic neuron less likely to fire
inhibitory post-synaptic potential
Name 2 examples of inhibtory neurotransmitters
serotonin
GABA
The (1)__________ of EPSP and IPSP inputs determine whether or not an (2)_______ _________ is produced, or how freuquently the neuron will (3)____
(1) summation
(2) action potential
(3) fire
What is the name of the insulating layer covering the axon?
myelin sheath
What does the myelin sheath allow the nerve impulse to do?
travel more rapidly
