Lesson 2 - Neurons Flashcards
What is a neuron
- Specialised nerve cell
* Moves electrical impulses through CNS
What is the cell body
Controls centre of neuron
What is the nucleus
Contains genetic material
What are dendrites
Receives electrical impulse (action potential) from other neurons/sensory receptors
What is an axon
Long fibre that carries electrical impulse from cell body to axon terminal
What is the myelin sheath
Insulating layer that protects axon and speeds up transmission of electrical impulse
What is the Schwann cell
Make up myelin sheath
What are the nodes of Ranvier
Gaps in myelin sheath
-speed up electrical impulse along axon
What are sensory neurons
- Located in sensory receptors
- Carry electrical impulse from sensory receptors to CNS via PNS
• Convert info from sensory receptors to electrical impulses
-converted to sensations (pain)
• Sensory impulses terminate at spinal cord (reflexes)
What are motor neurons
• Located in CNS
-project axons outside CNS
• Send electrical impulses via long axons to glands & muscles (effectors)
What do motor neurons release when stimulated
• Release neurotransmitters
-bind to receptors on muscles to trigger response
What are relay neurons
- Located in CNS
- Connect sensory neurons to motor neurons
- (during reflex arc) Relay neurons in spinal cord involved in analysis of sensations
