Biopsychology: neurons and synaptic transmission

Question 1

what is a neuron?

Answer 1

Neurons are nerve cells that process and transmit messages through electrical and chemical signals.

Question 2

what are the three types of neurons?

Answer 2

Sensory neurons
relay neurons
motor neurons

Question 3

what is the role of sensory neurons?

Answer 3

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

Question 4

what is the role of relay neurons?

Answer 4

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

Question 5

what is the role of motor neurons?

Answer 5

They connect the CNS to effectors such as muscles or glands. They have short dendrites and long axons.

Question 6

what is a dendrite?

Answer 6

carry nerve impulses from neighbouring neurons to
the cell body

Question 7

what is an axon?

Answer 7

carries the impulse away from the cell body down the length of the neuron.

Question 8

what is a myelin sheath?

Answer 8

fatty layer which covers the axon. It insulate and protects the axon from external influences that might effect the transmission of the nerve impulse down the axon.

Question 9

what are the nodes of ranvier?

Answer 9

these speed up the transmission of the impulse by forcing it to jump across the gaps along the axon.

Question 10

what are terminal buttons?

Answer 10

communicates with the next neuron in the chain across a gap known as the synapse.

Question 11

Is the inside of the cell negatively charged or positively charged when the neuron is at resting state?

Answer 11

negatively charged

Question 12

what happens to the inside of the cell when a neuron is activated by a stimulus?

Answer 12

The inside of the cell becomes positively charged for a split second causing an action potential to occur. This creates an electrical impulse that travels down the axon towards the end of the neuron.

Question 13

what is synaptic transmission?

Answer 13

The process by which neighbouring neurons communicate with each other by sending chemical messages across the synapse that separates them.

Question 14

what is a neurotransmitter?

Answer 14

they are chemicals released from the synaptic vesicle into the synapse by neurons. They affect the transfer of an impulse to another nerve
neurotransmitters are taken back up into the terminal buttons of neurons.

Question 15

what is the process of synaptic transmission?

Answer 15

1. nerve impule travels down and axon and reaches synaptic terminal
2. this triggers the release of neurotransmitters
3. the neurotransmitters are fired into the synaptic gap
4. neurotransmitters binds with the receptors on the dendrite of the adjacent neuron
5. if successfully transmitted the neurotransmitter is taken up by the post synaptic neuron
6. this message will continue to be passed in this way via electrical impulse.

Question 16

where are neurotransmitters released from and received by ?

Answer 16

released from presynaptic neuron
received by post synaptic neuron

Question 17

reflex arc

Answer 17

Stimulus
Receptor- ( sensory organs in the PNS conveys message along sensory neuron)

Sensory - sensory neuron sends the message to CNS where it connects with the relay neuron

Relay
Motor
Effector
Response

Question 18

what is excitation?

Answer 18

when a neurotransmitter such as adrenaline increases the positive charge of the postsynaptic neuron. This increases the likelihood that the postsynaptic neuron will pass on the impulse.

Question 19

what is inhibition?

Answer 19

when a neurotransmitter such as serotonin increases the negative charge on a postsynaptic neuron. This decreases the likelihood that a post synaptic neuron will pass on the electrical impulse.