Lesson 2 - Neurons

Question 1

Neurons

Answer 1

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

Question 2

Neurons
Parts

Answer 2

Cell Body - controls centre of the neuron
Nucleus - contains genetic material
Dendrites - receives electrical impulse (action potential) from other neurons or sensory neurons
Axon - long fibre that carries electrical impulses from cell body to axon terminal
Myelin Sheath - insulated layer protecting axon and speeds transmission of electrical impulses
Schwann Cells - make up myelin sheath
Nodes of Ranvier - gaps in the myelin sheath, speed up electrical impulses along the axon

Question 3

Neuron Diagram

Answer 3

Question 4

Types of Neurons

Answer 4

Sensory Neuron
Motor Neuron
Relay Neuron

Question 5

Sensory Neuron

Answer 5

Found in sensory receptors
Carry electrical impulses from the sensory receptors to the CNS via the PNS
Convert information from sensory receptors to electrical impulses
When impulses reach brain, converted into sensations so body can react appropriately
Some impulses terminate at spinal cord allowing for reflexes to occur without brain response

Question 6

Motor Neuron

Answer 6

Located in the CNS but project their axons outside the CNS
Send electrical impulses via long axons to the glands and muscles
Glands and muscles are called effectors
When motor neurons are stimulated, they release neurotransmitters that bind to the receptors on muscles to trigger response => movement

Question 7

Relay Neuron

Answer 7

Found in CNS
Connect sensory neurons to motor neurons so they can communicate
During a reflex arc, relay neurons in spinal cord are involved in analysis of sensation and decide on response without having to wait on brain to process and respond

Question 8

Neurons in the Body Diagram

Answer 8