Lesson 2: Neurons Flashcards
What are neurons?
specialised nerve cells that move ELECTRICAL impulses to and from the CNS
What are the 7 components of a nerve cell
1) dendrites
2) nucleus
3) axon
4) myelin sheath
5) nodes of ranvier
6) axon terminal
7) schwann cells
What is the function of dendrites?
receives an ACTION POTENTIAL from other neurons or sensory receptors
What is the function of the nucleus
Contains the genetic information of the nerve cell
What is the function of the axon
it is a long fibre that carries the electrical impulse from the cell body to the AXON TERMINAL
What is the function of the myelin sheath
INSULATING LAYER that protects the axon and SPEEDS up the transmission of electrical impulses
What are the nodes of ranvier
they are gaps in the myelin sheath that speed up the rate of electrical transmission
What are schwann cells
they are specialised cells which make up the myelin sheath
What is the axon terminal
Where the electrical impulse ‘ends’ and gets passed on to a new nerve cell
What are the 3 types of neurons
1) Sensory
2) Motor
3) Relay
Where are sensory neurons found?
In sensory receptors
What are sensory neurons responsible for?
1) convert information from SENSORY RECEPTORS into electrical impulses
2) carry electrical impulses TO the CNS via the PNS.
When information from the sensory neuron reaches the brain, what is it converted into?
converted into SENSATIONS so the body can react accordingly
Where do some sensory neurons terminate at + WHY
some terminate at the SPINAL CORD to allow reflexes to occur QUICKLY without waiting for the brain to respond
Where are motor neurons located?
in the CNS but project the AXONS outside the CNS
What are motor neurons responsible for?
1) send electrical impulses via long axons to glands and muscles (EFFECTORS) so they can affect function
What happens when motor neurons are stimulated?
they release NEUROTRANSMITTERS which bind the the receptors on muscles to trigger a response
Where are relay neurons located?
in the CNS
What are they responsible for?
1) connecting sensory neurons to motor neurons so they can COMMUNICATE with eachother
What do sensory neurons do during a reflex arc?
they are responsible for the analysis of SENSATION + decide how to respond WITHOUT waiting for the brain to process the pain.
