Neurons And Synaptic Transmission

Question 1

What are the three types of neurons

Answer 1

Motor, relay, sensory

Question 2

What is the role of the sensory neuron

Answer 2

To carry messages from the PNS to the CNS. They have long dendrites and short axons

Question 3

What is the role of the motor neuron

Answer 3

To connect the CNS to effectors such as muscles and glands, they have short dendrites and long axons

Question 4

What is the role of the relay neuron

Answer 4

To connect the sensory neurons to the motor neurons or other relay neurons. They have short dendrites and short axons

Question 5

What is synaptic transmission

Answer 5

The process by which a nerve impulse passes across the synaptic cleft from the presynaptic neuron to the postsynaptic neuron

Question 6

What is excitation

Answer 6

When a neurotransmitter increases the positive charge of the postsynaptic neuron, increasing the likelihood that the neuron will fire eg, adrenaline

Question 7

What is inhibition

Answer 7

When a neurotransmitter makes the charge of the postsynaptic neuron more negative, decreasing the likelihood that the neuron will fire eg. Serotonin

Question 8

What is a neurotransmitter

Answer 8

A chemical messenger that helps transfer the electrical impulse across the synapse from the presynaptic to the postsynaptic neuron

Question 9

What is summation

Answer 9

The net result of adding up the excitatory and inhibitory neurotransmitters binding to the receptors- determines whether or not the neuron fires

Question 10

Describe the process of synaptic transmission

Answer 10

• nerve impulse travel down presynaptic neuron
• it stimulates synaptic vesicles to release neurotransmitters which diffuse across the synapse to the postsynaptic neuron
• neurotransmitters bind to receptors on surface of postsynaptic neuron- has either inhibitory or excitatory effect
• likelihood of cell firing determined by summation