neurons and synaptic transmission

Question 1

what are the 3 types of neuron (in order)

Answer 1

• sensory neurone
• relay neurone
• motor neurone

Question 2

go to flashcards for diagram of neuron’s

Answer 2

-

Question 3

explain the structure of a neuron?

Answer 3

• cell body has nucleus= genetic material of cell
• dendrites- protrudes from cell and carries impulses towards cell
• axon carries impulses away from the cell
• axon covered in fatty layer of myelin sheath + speeds up electrical transmissions
• and sheath is segmented by nodes of Ranvier speeding up transmission of impulse
• terminal buttons at end of axon communicate with next neuron in synapse

Question 4

explain electrical transmission and firing of a neuron

Answer 4

• in resting state the inside of cell in negatively charged compared to outside
• when neuron activated by stimuli inside becomes positively charged for split second
• causes action potential, creates electric impulse that travels down axon to end of neuron

Question 5

explain chemical transmission in synaptic transmission?

Answer 5

• neurons communicate with each other= neural networks
• each separated by synapse and in that space is the presynaptic terminal and postsynaptic receptor site
• signals WITHIN neurons are transmitted electrically
• signals BETWEEN are transmitted chemically through synaptic transmission
• when electrical impulse reached end of presynaptic terminal= release of neurotransmitter from synaptic vessles

Question 6

explain a neurotransmitter?

Answer 6

• chemicals that diffuse across the synapse to next neuron in the chain
• once crossed it is taken up by postsynaptic receptor sites
• converted back to an electrical impulse and repeats in a other neuron
• each neurotransmitter has its own specific molecular structure that fits perfectly into post-synaptic receptor site

Question 7

what is excitation?

Answer 7

• neurotransmitters either have an excitatory or inhibitory effect on the neighbouring neuron
• neuron increases in positive charge and more likely to fire

Question 8

what is excitation?

Answer 8

-neuron increases in positive charge and more likely to fire

Question 9

what in inhibition?

Answer 9

-neuron becomes negatively charged and less likely to fire

Question 10

provide an example of inhibition ?

Answer 10

• neurotransmitters either have an excitatory or inhibitory effect on the neighbouring neuron
• serotonin causes inhibition in receiving neuron, resulting in it becoming negatively charged and less likely to fire

Question 11

why do neurone only fire in one direction?

Answer 11

-synaptic vesicles containing neural transmitter only present on pre-synaptic membrane
-there are only receptor sites on the post-synaptic neuron
- it is the binding of the neurotransmitter to the receptor which enables the signal/information to be
passed/transmitted on (to the next neuron).