L2 - Neurons

Question 1

What are Neurons?

Answer 1

Specialised nerve cells that move electrical impulses to and from the CNS

Question 2

What are the different parts of a neuron?

Answer 2

• Cell body: control centre of neuron
• Nucleus: contains genetic material
• Dendrites: receives electrical impulse from other neurons/sensory receptors
• Axon: a long fibre carrying electrical impulses from the cell body to the axon terminal
• Myelin Sheath: Insulating layer protecting the axon. Speeds up transmission of the electrical impulse
• Schwann Cells: Makes up the Myelin Sheath
• Nodes of Ranvier: Gaps in Myelin Sheath. Speeds up electrical impulses along the axon

Question 3

Disrobe a sensory neuron

Answer 3

• Found in sensory receptors
• Carry electrical impulses from sensory receptors to CNS via PNS
• Convert info from sensory receptors into electrical impulses
• When impulses reach the brain, they are converted into sensations, so body reacts quickly
• Some impulses are terminated at the spinal cord so reflexes can occur without a delay

Question 4

Describe a Motor Neuron

Answer 4

• Located in CNS, but axons are outside the CNS
• Send electrical impulses via long axons to effectors for function
• When stimulated, they release neurotransmitters that bind to muscle receptors to trigger a response, leading to movement

Question 5

Describe a Relay Neuron

Answer 5

• Found in CNS
• Conect sensory neutrons to motor neurons for communication
• involved in analysis of sensations and decide how to respond (involuntary response)