central nervous system (CNS)

Question 1

what is the central nervous system made up of

Answer 1

brain and spinal cord. surrounded and protected by cerebral spinal fluid which supplies nutrients and cushions the CNS from movement of the skull and spinal column

Question 2

what is a neuron (purpose of and describe)

Answer 2

transmits info
network of neurons and the connections between them make up the central nervous system. they do not touch each other so there is a synapse between them. then transmit nerve impulses along the length of an individual neuron and across the synapse

Question 3

what is the synapse

Answer 3

the junction between the axon of one neuron and dendrite of another. known as the synaptic gap

Question 4

what are neurotransmitters

Answer 4

chemical released when one neutron crosses the synaptic gap and is received by special receptor sites on the next neuron

Question 5

what are receptors

Answer 5

receptors are a certain shape prepared to receive a neuron transmitter from another neuron. if the neurotransmitter fits it is passed on. if it doesn’t the message is blocked

Question 6

what are hormones

Answer 6

chemicals released into the blood stream. produced by glands in the endocrine system. affect physiological and behavioural functions. hormones that affect behaviour act upon specific receptor sites in the brain. involved slow and longer acting responses

Question 7

what are genes

Answer 7

contained on chromosomes found within the nuclei of cells
made up of DNA
carry information from one generation to the next
influences development by triggering the productions of enzymes and proteins that are involved in the production of specific cells

Question 8

what is the sympathetic nervous system

Answer 8

responsible for preparing body for fight or flight

Question 9

what is the automatic nervous system

Answer 9

controls the body involuntary movements and controls the organs of the body

Question 10

what is the peripheral nervous system

Answer 10

all of the nervous system outside the CNS

Question 11

what is the somatic nervous system

Answer 11

controls voluntary movement and transmits signals to and from sense and muscles

Question 12

what is the parasympathetic nervous system

Answer 12

responsible for restoring the body to resting levels

Question 13

what are dendrites

Answer 13

finger like structures surrounding a cell body

Question 14

what is an axon

Answer 14

long extension from the cell body of a neuron

Question 15

what is an axon hillock

Answer 15

specialised part of the cell body of a neuron connecting to the axon

Question 16

what is the myelin sheath

Answer 16

cell that surround and protect axons forming an insulation layer

Question 17

what are the nodes of ranvier

Answer 17

areas around an axon where the myelin sheath thins

Question 18

what are the synaptic buds

Answer 18

small structures at the end of an axon that contains neurotransmitters that carry the neurones that carry the neurones messaged into the synapse

Question 19

what is GABA

Answer 19

inhibitor of messages and calming

Question 20

what is norepinephrine

Answer 20

gives attentions and prepares for fight or flight

Question 21

what is acetylcholine

Answer 21

memory and learning

Question 22

what is dopamine

Answer 22

pleasure feelings and addiction

Question 23

what is glutamate

Answer 23

cognitive functioning and dangerous if too much

Question 24

what is serotonin

Answer 24

happiness and good mood - low levels gives depression§

Question 25

what is reuptake

Answer 25

neurontransmitter is absorbed back into the presynaptic neuron

Question 26

what is the excitatory postsynaptic potential

Answer 26

makes the neurones more likely to fire an action potential

Question 27

what is action potential

Answer 27

electrical impulse in a neuron

Question 28

how do neurones work

Answer 28

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

Question 29

what is the effect of caffeine

Answer 29

suppresses the actions of adenosine, so increases neural activity so temporary increases in mental alertness and thought processing and reduces drowsiness and fatigue. does not directly increase energy metabolism and will in long term suppress it. reduces blood flow to brain and can lead to headaches

Question 30

what is the effect of nicotine

Answer 30

binds to and activates receptors called the cholinergic receptors. normally activated when they bind to acetylcholine (maintain healthy respiration, heart function and muscle movement). nicotine has a similar structure to acetylcholine, it disrupts normal functioning.
pain, anxiety and other negative symptoms are relieved and positive sensations are increased

Question 31

what is the effect of amphetamines

Answer 31

stimulants. increase the activity of dopamine and norepinephrine. cause the release of dopamine and blocks reuptake. inhibits the storage of dopamine in vesicles and inhibits the destruction of dopamine by enzymes. short term effects are an increased heart rate and reduced appetite, long term effects are weight loss an tremors.

Question 32

what are the strengths of this synaptic transmission explanation

Answer 32

method has scientific credibility, brain scanning is a strong method as it can be reliable if more than one person checks the data
evidence from people showing certain behaviour who have low levels of certain neurotransmitters in the brain. supports the idea that synaptic transmission is how messages pass in the brain
patients with parkinsons disease are offered a drug called L-dopa they can experience hallucinations (symptom of schizophrenia - high levels of dopamine, synaptic transmission can help to explain various disorders)

Question 33

weaknesses of the synaptic transmission explanation

Answer 33

cannot generalise animals to humans as there are differences
argument relating to cause and effect - do genes cause the abnormal levels of neurotransmitters or does it begin when neurochemical activity changes
quite simplistic - Allen and Stevens fond that less than half the neurotransmitters in transmission arrived from the presynaptic neurones being picked up by the post synaptic neurones - more complex