Biopsychology: structure and function of neurones Flashcards
What is the function of dendrites?
sends the signal down the axon
What is the function of the nucleus?
contains genetic material
What is the function of Nodes of Ranvier?
speeds up transmission
What is the function of the myelin sheath?
it is a fatty layer that protects the axon and speeds up electrical transmission
What is the function of the axon?
carries the impulses away from the cell body down the neurone
What is the function of an axon terminal button?
signal leaves the neurone and is sent to the next neurone across a synapse or to an organ.
What is synaptic transmission?
the process for transmitting messages from neuron to neuron.
What is a synapse?
a specialised gap between neurons through which the electrical impulse from the neuron is transmitted chemically.
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 positively stimulated by a stimulus?
the inside of the cell becomes positively charged for a split second causing an action potential to occur. This creates an electrical impulse that travels down the axon towards the end of the neuron.
Explain the process of synaptic transmission.
When the electrical impulse reaches the end of the neurone (pre-synaptic terminal) it triggers the release of neurotransmitters from tiny sacs called synaptic vesicles.
Once the neurotransmitter crosses the gap, it is taken up by the post synaptic receptor site (dendrite of next neuron). Here, the chemical message is converted back into an electrical impulse.
What is excitatory transmission?
this occurs when a neurotransmitter such as adrenaline, increases the positive charge of the post synaptic neuron. This increases the likelihood that the neuron will fire and pass on the electrical response.
What is inhibitary transmission?
This occurs when a neurotransmitter, such as serotonin, increases the negative charge of the post synaptic neuron. This decreases the likelihood that the neuron will fire and pass on the electrical response.
What is the function of a motor neuron?
motor neurons carry signals from the CNS which helps both organs, including glands and muscles, function.
What is the function of a sensory neurone?
They tell the the rest of the brain about the external and internal environment by processing information taken from one of the five senses.
