Nervous System, Neurons, And Neurotransmitters Flashcards
1
Q
Nervous system
A
- Central nervous system
- peripheral nervous system
2
Q
Central nervous system (CNS)
A
- brain and spinal cord
3
Q
Peripheral nervous system (PNS)
A
- transmit signals between the CNS and rest of the body
- somatic and autonomic nervous systems
4
Q
Somatic nervous system (SNS)
A
- transmits information from bodies sensory receptors to CNS and CNS to skeletal muscles
- responsible for actions that are voluntary
5
Q
Autonomic nervous system (ANS)
A
- transmits information from smooth muscles and organs to CNS and vice versa
- responsible for activities that are involuntary, although some activities can be brought under voluntary control using biofeedback or other techniques
- sympathetic and parasympathetic nervous systems
6
Q
Sympathetic nervous system
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- prepares body for action
- during fight or flight causes people dilation sweating increased heart rate and respiration rates and inhibits digestion and sexual activity
7
Q
Parasympathetic nervous system
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- rest and relaxation
- causes body to return to pre-emergency state after fight or flight
8
Q
Parasympathetic and sympathetic nervous system
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- both active to some degree most of the time and work together cooperatively for some functions
Ex) sexual response parasympathetic nervous system necessary for erection and sympathetic nervous system responsible for ejaculation
9
Q
Neurons
A
- responsible for communicating information to the nervous system
10
Q
Glia
A
- provide neurons with structural support, insulation, and nutrients
- produces myelin
11
Q
Nervous system
A
- two types of cells: neurons and glia
12
Q
Structure of neuron
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- very in size and shape
- all have one or more dendrites, Soma and an axon
13
Q
Dendrites
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- receive information from other cells
14
Q
Soma
A
- contains nucleus, mitochondria, ribosomes, and other elements essential for the survival of the cell
15
Q
Axon
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Transmits info to other cells
- some are insulated with myelin with speeds up conduction of information
16
Q
Conduction within neurons
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- information conduction is an electrochemical process
- begins with neurons dendrites receiving sufficient stimulation from other neurons
- prior to stimulation neuron is in resting state (fluid inside is negatively charged)
- once it stimulated sufficiently channels in the cell membrane open allowing a positively charged sodium ion to enter cell which makes it become depolarized
- once simulation reaches minimum threshold complete depolarization occurs and triggers an electrical impulse (action potential)
- after action potential neuron returns to arresting state
17
Q
Action potential
A
- all or nothing responses
- Have same intensity
- stimulus intensity is encoded by frequency of action potentials or number of neurons that generate action potentials
18
Q
Transmission between neurons
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- transmission of info equals synaptic transmission
- chemical
- begins when action potential reaches acts on terminal which causes the release of a neurotransmitter into synaptic cleft
Once neurotransmitter hasn’t affect on a post gymnastic neuron it is an activated by being absorbed by a priestsynaptic neuron or broken down by an enzyme
19
Q
Axon terminal
A
End of an axon
20
Q
Synaptic cleft
A
- space between the axon terminal of the priestsynaptic neuron and the dendrite of an adjacent postsynaptic neuron
21
Q
Neurotransmitters
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- have an excitatory or inhibitory effect
22
Q
Excitatory
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- increased likelihood of an action potential in a postsynaptic neuron
23
Q
Inhibitory
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- decrease the likelihood of a action potential occurring in a post-synaptic neuron
24
Q
Neuroplasticity
A
- aka brain plasticity
. - brain’s ability to modify, change, and adapt both structure and function throughout life and in response to experience
25
Q
Four types of neuroplasticity
A
- homologous area adaption
- cross modal reassignment
- map expansion
- compensatory masquerade
26
Q
Homologous area adaption
A
- in response to early damage to a particular area of the brain, functions of these area are shifted to corresponding areas and opposite hemisphere
- pre-existing functions of corresponding area may be negatively affected
Ex) damaged prior to lobe in childhood, left parietal lobe takes over visual spatial functions and mathematical functions normally carried out by this area Maybe impaired
27
Q
Cross modal reassignment
A
- brain area responsible for processing particular type of sensory input is deprived of input and function of neurons in that area change
Ex) neurons and visual cortex of child born blind do not receive and process visual input so neurons may receive and process so medicine sensory input which allows child to create cognitive representations of a physical world
28
Q
Map expansion
A
- temporary or permanent enlargement of functioning cortical regions as a result of practice or exercise
- involve recruiting neurons from borders of that region
- often occurs when you practice or learn a new skill
29
Q
Compensatory masquerade
A
- person no longer able to performs a task using cognitive processes that were mediated by a recently damaged area of the brain
- instead, use alternative cognitive processes that were mediated by an intact area of the brain
Ex) lose spatial sense as a result of brain injury and rely on memorizing landmarks ticket from one place to another
30
Q
Neurotransmitters
A
- chemical substances that transmit information between neurons
- classified as small molecule neurotransmitters or neural peptides based on size and the way they are synthesized
31
Q
Small molecule neurotransmitters
A
- synthesize and stored in the axon terminal
- dopamine
- acetylcholine
+ Glutamate - norepinephrine
- serotonin
- Gaba
32
Q
Neuropeptides
A
-enkephalin
– endorphin
- endogenous opioids that have analgesic and euphoric effects
33
Q
Dopamine
A
- excitatory and an inhibitory
- movement, personality, mood, and sleep
- contributor to several disorders
- low levels in substantia negra equals Parkinson’s disease
- high levels in caudate nucleus equals tourette’s disorder
- dopamine hypothesis equals schizophrenia due to high levels of dopamine or hyperactivity of dopamine receptors
34
Q
Mesolimbic dopaminergic pathway
A
- begins at ventral tegmental area and ends at ventral striatum (nucleus accumbens)
- essential part of reward circuit
- roll and reinforcing the effects of substances of abuse
35
Q
Dorsilateral prefrontal cortex
A
- initiates motivation to obtain a reward by sending signals to the ventral tegmental area and nucleus accumbens
36
Q
Mesocortical dopa menergic pathway
A
- begins at ventral teg mental area and ends in the prefrontal cortex
- involved in emotion, motivation, and executive cognitive functions
37
Q
Tuberinfundibular dopaminergic pathway
A
- begins in the hypothalamus and ends in the pituitary gland
- plays a role in hormone regulation especially inhibition of prolactin release
38
Q
Nigrostriatal dopaminergic pathway
A
- begins in the substantial negro and ends in the dorsal striatum (caught a nucleus and putamen)
- key role in the production of purposeful movement
39
Q
Acetylcholine
A
- both excitatory inhibitory
- movement, arousal, attention, and memory
- causes muscles to contract
- low levels in the and torhenial cortex and hippocampus linked to early memory loss associated with Alzheimer’s
40
Q
Myasthenia gravis
A
- autoimmune disorder caused by muscle weakness
- destroys ACH receptors at neuromuscular junctions
41
Q
Glutamate
A
- excitatory
- movement, emotions, learning, and memory
- excessive glutamate causes cell damage and death (glutamate induced exotoxicity)
- Caesar disorders, strokes, and neurodegenerative diseases (Huntington’s and Alzheimer’s)
42
Q
Neuropinephrine
A
- excitatory
- arousal, attention, learning, memory, stress, and mood
43
Q
Catecholamine hypothesis
A
- some forms of depression are caused by deficiency of norepinephrine
- mania is caused by excessive
44
Q
Serotonin
A
- 5-HT
- inhibitory
- arousal, sleep, sexual activity, mood, appetite, and pain
- low levels equal depression, increased risk of suicide, bulimia, OCD, and migraines
- high levels= cause anxiety and obsessive thinking, food restriction lower serotonin which alleviates the symptoms
- higher than normal blood levels found in people with autism
- chronic schizophrenia equals in large cerebral ventricles and cerebral atrophy
45
Q
GABA
A
- inhibitory
- memory, arousal, sleep, and motor control
- low levels= insomnia, seizures, and anxiety
- benzos reduced anxiety and induce sleep by amplifying effects of gaba
- degeneration of gaba and ACH cells and basal ganglia contribute to motor symptoms of Huntington’s
46
Q
Psychoactive drugs
A
- classified based on effects of neurotransmitters
- agonist
- partial agonist
- inverse agonist
- antagonist
47
Q
Agonists
A
- mimic or increase effects of a neurotransmitter
- direct agonist or indirect agonist?
48
Q
Direct agonists
A
- attached to a receptor site and act like a neurotransmitter
49
Q
Indirect agonists
A
- increased the availability of the neurotransmitter but do not attach to receptor site
50
Q
Partial agonist
A
- produce effects that are similar to but weaker than the effects of a neurotransmitter
51
Q
Inverse agonists
A
- produce effects that are opposite of the effects of a neurotransmitter or agonist
52
Q
Antagonists
A
- do not produce any effects on their own, but block or reduced effects of a neurotransmitter or agonist
- direct antagonist or indirect antagonist
53
Q
Direct antagonist
A
- binds to and blocks receptors
- prevents a neurotransmitter from attaching to the receptor
54
Q
Indirect antagonist
A
- prevents the production or release of a neurotransmitter by a presynaptic cell
