Neurons Flashcards
What is a neuron?
A specialised cell within the nervous system
What do neurons do?
Communicate with 1000s of other cells at a time in huge networks
New networks are formed when we learn something new and they adapt as we have new experiences
What is plasticity?
The brains ability to change and adapt because of experience
What are dendrites?
Branches at the top end of a neuron that receive messages from other neurons
What is the cell body?
The main part of the cell (contains the nucleus and mitochondria)
Has key components of the cell
What is the nucleus?
Has the genetic material of the neuron and stores DNA
What is the axon hillock?
Connects the cell body to the axon
Generates the electrical impulse down the axon (action potential)
What are Schwann cells?
Glial cell- forms the myelins heath and supplies nutrients to axons
What are nodes of ranvier?
Gaps between myelin sheaths- speeds up action potential
What is the myelin sheath?
Fatty deposit provides electrical insulation
What is a synapse?
Gap between dendrite and the terminal button of another where chemical messages can be passed
What is an axon/synaptic terminal?
End of the axon that leads to the terminal buttons
Transmits messages via neurotransmitters to other cells
What is an axon?
A long branch from the cell body that passes electrical impulses down to the end of the neuron to allow it to communicate with others
Where are sensory neurons found
In receptors (eyes, ears, skin)
What do sensory neurons do/
Carry nerve impulses to the spinal cord and brain
What happens once the nerve impulses reach the brain? (Sensory neurons)
They are translated into sensations (vision, hearing etc)
Where are relay neurons found?
In the brain and spinal cord
What do relay neurons allow for?
Sensory and motor neurons to communicate
What do relay neurons do?
Integrate sensory information and regulate motor activity
Where are motor neurons found>
In the CNS- they control muscle movement
What happens when motor neurons are stimulated?
They release neurotransmitters that bind to the receptors on muscles to trigger a response- leading to movement
Takes messages from CNS to muscles and glands
What happens to a neuron during an excitatory reaction?
It is more likely the next neuron will fire e.g. doing exercise releases dopamine
What happens to neurotransmitters during an excitatory reaction?
They bind to the receptors on the post-synaptic membrane- the post-synaptic neuron becomes positively charged and creates an action potential
What happens to the neuron during an inhibitory reaction?
Less likely the next neuron will fire
Neurotransmitters bind to the receptors on the post-synaptic membrane- the post-synpatic neuron becomes more negatively charged and does not create an action potential
