Neurons and Synaptic Transmission Flashcards
What are the three types of neurons
Motor, relay and sensory
How big are neurons
vary from mm to m
What is in a neuron cell body
nucleus holding genetic material and dendrites protruding from cell body
What do dendrites do
carry nerve impulses from other neurons
What do axons do
carry impulses down length of neuron - covered in fatty layer known as myelin sheath
Myelin sheath
protects axon and speeds up electrical transmission of impulse
Nodes of ravier
split up myelin sheath, speed up electrical transmission of impulse
Terminal buttons
found at end of axon, communicates with next neuron in chain across synapse
How are neurons in the body laid out
neurons are linked in chains
the receptor passes a signal to the sensory neuron - this then passes to the relay neurone in the spinal cord - this is then passed to motor neuron - passes it to effector
Neuron layout
Receptor - sensory - relay - motor - effector
What is the charge inside a cell
negative charge when neurone is in resting state
What is the charge outside of a cell
postive charge
What happens when a stimulus activates a neuron
for a split second the inside of the cell becomes positively charged - creates action potential
What is action potential
it creates electrical impulse which travels down the axon towards end of neuron
What are neural networks
Groups which neurons communicate with each other in - synapse separates others
How are signals transmitted between neurons
chemically
What is a presynaptic terminal
the end of the neuron - neurotransmitters are triggered to release from synaptic vesicles when electrical impulse gets to presynaptic terminal
What are neurotransmitters
chemicals that diffuse across synapse of one neuron to next
Many different types in the brain
all have specific structures which fit into corresponding post-synaptic receptor sites
What is a postsynaptic receptor site
dendrites - pick up neurotransmitters from other neuron
Chemicals are converted back into electrical impulse
What is am inhibitory neurotransmitter
E.g. serotonin causes inhibition - neuron becomes more negatively charged and less likely to fire
What is am excitatory neurotransmitter
E.g. adrenaline causes excitation - neuron becomes more positively charged and more likely to fire
