L2- Neurons Flashcards
1
Q
what are neurons?
A
Specialised nerve cells that move electrical impulses to and from the central nervous system.
2
Q
What is the role of the cell body, nucleus, dendrites and axon of a neuron?
A
- Cell body- control centre of neuron.
- Nucleus- contains genetic material.
- Dendrites- receives electrical impulse from other neurons/ sensory receptors.
- Axon- a long fibre that carries electrical impulse from the cell body to the axon terminal.
3
Q
What is the structure of a neuron?
A
- cell body
- nucleus
- dendrites
- axon
- myelin sheath
- schwann cells
- nodes of ranvier
4
Q
What is the Myelin sheath in neurons?
A
insulting layer that protects the axon and speeds up transmission of the electrical impulse.
Schwann cells- make up myelin sheath.
5
Q
what are nodes of ranvier in neurons?
A
gaps in myelin sheath. Speed up electrical impulse along axon.
6
Q
Sensory neuron. Function/location/structure?
A
- found in sensory receptors.
- convert information from sensory receptors into electrical impulses and carry them from the receptors to the CNS via the PNS.
- when reached the brain, converted into sensations (eg. Pain).
- some impulses terminate at spinal cord. Allowing reflexes to occur quickly. (Don’t have to go to brain)
- have long axon. Cell body located in middle.
7
Q
Motor neuron. Function, structure, location?
A
- located in CNS, however project their axon outside of cns.
- send electrical impulses via long axons to the glands and muscles (effectors) so they can affect function.
- once stimulated, they release neurotransmitters that bind to receptors on muscles to trigger a response.
8
Q
Relay neuron. Function/location/structure?
A
- found in the CNS.
- connect sensory neurons to motor neurons so that can communicate with each other.
- during reflex arc, the relay neurons in spinal code analyse the sensation and decide response without waiting for brain to process it.
- short axon. No myelin sheath.
