Biologicalš§ ā¢ Neurotransmission + Studies Flashcards
Roughly what percentage of neurons are located in the brain?
80%
Label this diagram of a neuron
In what two ways do neurons transmit information?
electrically and chemically
What is another word for the cell body of a neuron?
the soma
What does the cell body/ soma of a neuron contain?
The nucleus containing the genetic mateiral of the cell
What are dendrites?
(the receving part of the neuron) Branch-like structures that stick out from the cell body of the neuron; the purpose of dendrites is to carry impulses from neighbouring neurons to the cell body to then be passed through the rest of the neuron
What is the axon?
A tube-like structure that carries impulses away from the cell body down the entire length of the neuron
What is the meylin sheath?
the fatty layer that covers the axon in many neurons
What is the purpose of the meylin sheath?
- to protect the axon
- speed up electrical transmission impulse for neuron to work at optimum speeds
What are the nodes of ranvier?
gaps on the axon inbetween the meylin sheath
What is the purpose of the nodes of ranvier?
They allow for the increase of speed from the meylin sheath by forcing the electrical impulse to jump across teh gaps along the length of the axon consequently increasing speed by making the journey shorter
What is the axon terminal?
The extension of the main axon into branch-like structures similar to that of dendrites (in appearance), they contain axon terminal buttons.
What are axon terminal buttons?
The small knobs on the end of the axon terminal that contain synapic vessicles used for neurotransmission
What is the tiny gap between neurons called?
synapse/ synaptic gap/ synaptic cleft
What is synaptic transmission?
A chemical process where by biochemical substances called neurotransmitters are used to transmit electrical signals from a neuron, chemically across a synapse
What are synaptic vessicles?
Tiny sacs full of neurotransmitters located in the axon terminal button
What is a post/presynaptic neuron?
- presynaptic neuron = neuron impulse is coming from
- postsynaptic neuron = neuron impulse is traveling too
From what part of the neuron on the presynaptic neruon do the neurotransmitters travel to on the postsynaptic neuron?
Neurotransmitters travel from the axon terminal buttons of the presynaptic neuron and to the dendrites of the postsynaptic neuron
What is an Action Potential?
The electrical impulse that is sent down a neuron
What triggers the synaptic vessicles to release the neurotransmitters into the synapse?
The presence of an Action Potential; when an action potential reaches the end of a neuron/ the axon terminal/terminal buttons
Label this diagram of Neurotransmission
Describe the process of neurotransmission
- AP arrives at axon terminal button, consequently triggering the synaptic vessicles to release neurotransmitters into the synapse
- The released neurotransmitters diffuse across the synapse until they arrive at the dendrite of the postsynaptic neuron
- The dentrite contains specialised receptor sites complementary in shape to the neurotransmitters
- Neurotransmitters are uptaken and bind to complementary receptors though **lock and key **; postsynaptic neuron then converts the chemical signal back into an electrical one to then fire another AP along the neuron
What is reuptake?
When neurotransmitters that have remained in the synapse are reabsorbed by the presynaptic neuron to then be used again
What is uptake?
Just what happens normally when neurotransmitters travel from pre-to-post-synaptic neuron
