Lesson 2 - Neurons Flashcards
What is a neuron ?
A Neuron is a specialised nerve cell that move electrical impulses to and from the CNS>
What are the parts of a neuron?
Cell body - Control centre of the neuron
Nucleus - Contains genetic material (within cell Body)
Dendrites - receive the electrical impulses from other neurons or sensory receptors
Axon- Long fibre tah==hat carries impulses from cell body to the axon terminal
Myelin sheath - Insulatory layer that protects axon and catalyses transmission of impulses.
Schwann cells- Make up the myelin sheath
Nodes of Ranvier- Gaps in the Sheath. Speed up transmission.
What are the three types of Neuron?
Sensory, Motor, Relay
What do the sensory neurons do?
They carry electrical impulses from the sensory receptors to the CNS via the peripheral nervous system. They convert info from the the sensory receptors into electrical impulses. They become sensations in the brain so a reaction can take place. Some impulses stop at the spinal cord so reflexes can take place.
What do Motor neurons do?
They send electrical impulses via long axons to the glands and muscles so they can affect function. When a motor neuron is stimulated they release neurotransmitters that bind to receptors on muscles, this triggers a response and leads to movement.
What do Relay neurons do?
They connect sensory neurons to motor neurons so they can communicate.
