A+P - Psych Flashcards
(187 cards)
1
Q
What is the resting membrane potential?
A
-70mV
(The potential inside the neuron is 70 mV l< the potential outside the neuron.)
2
Q
What two ions cause an action potential to occur?
A
Na+ & K+
3
Q
Which ion is in higher concentration outside the cell?
A
Na+
4
Q
Which ion is in higher concentration inside the cell?
A
K+
5
Q
Na+ wants to flow…
A
into the neuron (cell)
6
Q
K+ wants to flow…
A
out of the neuron (cell)
7
Q
Describe the concentration gradient.
A
Particles want to move from high to low concentration
8
Q
The (-) polarity (-70mV) inside the neuron attracts…
A
Na+ & K+
9
Q
Describe electrostatic pressure/gradient.
A
- opposites [in charge] attract
- like charges repel
10
Q
What is the role of ion channels?
A
to allow specific ions to cross the membrane
11
Q
Role of Na-K pumps
A
ushers out Na+ at a higher rate than K+ when the neuron is at rest
12
Q
NOTE
A
- K+ is actively pumped in
- Na+ is actively pumped out (after leaking in across membrane)
13
Q
How much Na+ is pump across the membrane?
A
3
14
Q
How much K+ is pumped across the membrane?
A
2
15
Q
What are the 2 kinds of postsynaptic potentials?
A
- excitatory postsynaptic potentials (EPSPs)
- inhibitory postsynaptic potentials (IPSPs)
- both are graded potentials meaning the size of the potential incr w/ the amount of stimulation
16
Q
Describe excitatory postsynaptic potentials (EPSPs)
A
they depolarize the cell
17
Q
Describe inhibitory postsynaptic potentials (IPSPs)
A
hyperpolarize the cell
18
Q
What does hyperpolarization cause?
A
makes it more difficult to have firing of the neuron; require more stimulation
19
Q
What does PSPs mean?
A
Postsynaptic Potentials
20
Q
What are the 2 methods of causing multiple postsynaptic potentials?
A
- Spatial Summation
- Temporal Summation
21
Q
When does spatial summation occur?
A
when there is simultaneous stimulation at different parts of the neuron
22
Q
Spatial summation NOTE
A
Can be a combo of multiple EPSPs, multiple IPSPs, or a mix of both
23
Q
What are the 3 possibilities of spatial summation?
A
- 2 simultaneous EPSPs sum to produce a greater EPSP
- 2 simultaneous IPSPs sum to produce a greater IPSP
- a simultaneous IPSP & EPSP cancel each other out
24
Q
When does temporal summation occur?
A
when 2 PSPs happen rapidly in succession at the same synapse to form a greater signal
–> meaning a single neuron - 2 signals
25
Is temporal summation inhibitory, excitatory or both?
Either 2+ inhibitory OR 2+excitatory
26
What happens when the membrane reaches threshold of excitation?
voltage-activated ion channels are opened
- Na+ > K+
27
What happens after an action potential occurs?
a refractory period
28
What are the 2 types of refractory periods?
- absolute
- relative
29
Is it possible for another AP to occur during the absolute refractory period?
impossible to initiate another action potential
30
Is it possible for another AP to occur during the relative refractory period?
- it's harder to initiate another AP (must apply higher than normal levels of stimulation to create another AP)
31
What is the consequence of the refractory period?
neural firing rate is related to stimulus intensity.
32
When does **high intensity stimulus** occur?
immediately after absolute refractory period
33
When does **low intensity stimulus** occur?
after absolute AND relative refractory periods
34
Where does saltatory conduction occur?
in myelinated neurons
35
Describe saltatory conduction.
APs travel the node of Ranvier which allows for quicker conduction down the neuron
36
What drives the process of exocytosis?
opening of Ca+ channels
37
What does exocytosis lead to?
the release of neurotransmitter into the synapse
38
What are the two categories of neurotransmitters?
- small-molecule
- large- molecule
39
How are small-molecule neurotransmitters transported?
Packaged into vesicles by the Golgi complex
40
How are large-molecule neurotransmitters transported?
Carried down to the terminal buttons by microtubules
41
Describe coexistence
A single terminal button can contain both small- & large-molecule neurotransmitters
42
What is a receptor?
a PRO w/ a binding site for specific neurotransmitters
43
What is a ligand?
any molecule that binds to another
44
Describe an ionotropic receptor?
pass neurotransmitter through ligand-gated ion channels (faster transmission, shorter-lasting effects)
45
Is a neurotransmitter a ligand?
YES
46
What are the 2 categories of postsynaptic receptors?
- ionotropic
- metabotropic
47
Describe an metabotropic receptor?
neurotransmitter binds to a signal PRO, which then releases its G- protein, which finally opens a path for the ions to enter (slower transmission, longer-lasting effects)
48
What 2 mechanisms prevent the collection/build up of neurotransmitter in the synapse?
- reuptake
- enzymatic degradation
49
Describe reuptake.
neurotransmitter drawn back into presynaptic buttons by transporter mechanisms
50
Describe enzymatic degradation
neurotransmitter degraded (broken apart) in the synapse by enzymes
51
Which neurotransmitters most often acts directly on neighboring neurons?
small-molecule neurotransmitters
52
Which neurotransmitters acts indirectly on synaptic activity?
Neuropeptides (large-molecule
neurotransmitters)
53
Describe endorphins
Large-molecule neurotransmitter or neuromodulator in the PNS/CNS & hormone in the pituitary
54
When are endorphins released?
in times of pain/stress & is **inhibitory** (“pain relief”) – stronger than morphine
55
What do endorphins bind to? causing?
- opioid receptors
- prevents release of substance P
56
What is beta-endorphin?
an endogenous opioid
- one of the neurochemicals involved w/ exercise-induced euphoria (runner's high)
57
Endorphins are associated w/
states of pleasure, including such emotions brought upon by laughter, love, sex & even appetizing food
58
Dopamine plays a big role in...
addiction
59
Dopamine is a ___ molecule neurotransmitter, but can also act as a ___.
- small
- hormone
60
Dopamine is considered a...
neurohormone
61
Dopamine is mainly known for...
sense of pleasure/motivation it provides, but not known to have many other roles
62
Dopamine plays a role in which key things in the body?
- learning & attention
- mood regulation
- heart & kidney function
- pain processing
63
Imbalances in dopamine are linked to
- addiction
- Parkinson's disease
- various mental health concerns
- pain pleasure motivation
64
Is glutamate (GLU) excitatory or inhibitory the brain?
excitatory
65
What is the most common excitatory neurotransmitter across the whole nervous system (brain)?
glutamate (GLU)
66
Glutamate is important for...
learning, memory, and other various cognitive functions
67
What results in neural cell death?
overproduction of endogenous (but not dietary) glutamate
68
Imbalances in glutamate (GLU) is linked to...
- ALZ Dz
- Parkinson's Dz
- brain injury
- stroke
69
Describe serotonin.
inhibitory neurotransmitter
- also a neurohormone
70
Serotonin (5-HT) function
helps regulate many key biological functions related to survival
--> sleep, mood, libido, **anxiety, pain**, appetite
71
Imbalances in serotonin causes
(typically deficiencies)
disorders w/ Sx of anxiety, depression, &/or chronic pain
72
Describe norepinephrine (NE).
functions more as a neurotransmitter vs a neurohormone
73
NE also contributes to...
mood, memory, & ability to focus
74
NE aka
noradrenaline
75
NE is primarily known for its contributions to the ___ response.
fight-or-flight
76
NE works on which system for fight-or-flight?
sympathetic nervous system
77
Imbalances in NE are linked to...
- PTSD
- Parkinson's Dz
- ADHD
78
Describe Gamma-Aminobutyric Acid (GABA)
inhibitory neurotransmitter
79
What is the most common inhibitory neurotransmitter of the brain?
GABA
80
What effect does GABA have on the brain?
produces a calming effect
- reduces in stress, fear, & anxiety
- helps one fall & stay asleep
81
Imbalances in GABA is linked to...
- schizophrenia
- ASD
- anxiety disorders
- depression
- seizures
- hypersomnia
82
Chart: Adrenaline
- **fight or flight neurotransmitter**
- stressful or exciting situations
- incr HR & blood flow
83
Chart: Noradrenaline
- **Concentration neurotransmitter**
- attention & responding actions also fight-or-flight
- contracts BVs & incr blood flow
84
Chart: Dopamine
- **pleasure neurotransmitter**
- pleasure, addiction, movement & motivation
85
Chart: Serotonin
- **mood neurotransmitter**
- well-being, happiness, sleep cycle, digestive regulation
- affected by exercise & light exposure
86
Chart: GABA
- **calming neurotransmitter**
- calms firing of nerves, high levels improve focus, low levels cause anxiety
- motor control & vision
87
Chart: Acetylcholine
- **learning neurotransmitter**
- thought, learning, memory
- activates muscles, attention & awakening
88
Chart: Glutamate
- memory neurotransmitter
- **most common brain neurotransmitter**
- involved in learning & memory, regulates development & nerve contracts
89
Chart: Endorphins
- euphoria neurotransmitter
-released during exercise, excitement & sex
- well-being & euphoria
- reduce pain
90
For psychpactive drugs to produce effects, what must they do?
enter the brain
91
What must psychoactive drugs cross to enter the brain?
blood-brain-barrier
92
The BBB acts as a...
filter that makes it difficult for chemicals to pass from the BVs of the CNS into its neurons
93
Effects can partially depend on ___. The route of administration influences the ___ that the drug reaches the site of action.
- drug administration
- rate/degree
94
ROA: Describe Oral ingestion
- Absorbed through intestines into bloodstream
- Relatively easy/safe
- Effects are relatively slow
- Unpredictable (absorption varies w/ what is in stomach)
95
ROA: Describe Injection
- Effects are strong, fast, predictable
Three types:
- Subcutaneous (just below skin)
- IM (into large muscles)
- IV (directly into veins/bloodstream)
96
ROA: Describe Inhalation
- Absorbed into the bloodstream through capillaries in the lungs
- Difficult to regulate dose
97
ROA: Describe Mucous Membrane Absorption
- Mucous membranes can absorb drugs very quickly
- Can be administered through any mucous membrane, w/ a very commonly-used one being inside the nose
(i.e., snorting)
98
Once inside the brain, how do the drugs take their effect? (2)
Agonist or Antagonist
99
What is an agonist?
Molecule that incr a neurotransmitter’s action
100
What is an antagonist?
Molecule that inhibits or blocks a neurotransmitter’s action
101
The actions of most drugs are terminated by enzymes in the liver, which is called...
drug metabolism
102
How small amounts of the unmetabolized drugs eliminated?
- urine
- sweat
- feces
- breath
- breastmilk, etc
103
Describe Cytochrome P450 (CYP)
a hemePRO that has a key role in metabolism of drugs
104
What is considered a major mediator of drug-drug interactions?
Cytochrome P450 (CYP)
105
NOTES
Genetics or polymorphisms can causes CYP changes causing more/less metabolism of drugs
106
Define drug tolerance
a state of decr sensitivity to a drug’s effect that results from prior exposure to that drug
107
List the 2 key ways drug tolerance an be measured.
1. How much one’s response decr when the same amount of the drug is administered
2. How much more of the drug needs to be administered to produce the same degree of effect
108
What are the 2 types of tolerance?
1. metabolic tolerance
2. Functional tolerance
109
Define metabolic tolerance
results from a decr in the amount of drug that is able to reach the target cells
110
Describe functional tolerance
results from a decr in the ability of the drug to influence the target cells
111
How is functional tolerance similar to DM?
down regulation of receptors
- now it takes more drugs to get high
112
When is tolerance greatest?
when administration is in same situation as previous administrations.
113
Define drug withdrawal syndrome.
an illness that is triggered by sudden elimination of a drug that has perpetually been in the body in significant amounts.
114
NOTE
Exposure produces compensatory NS changes to offset drug’s effects
Elimination sees these compensatory changes (w/o the drug present) manifested as withdrawals
115
Describe physical dependence
When someone suffers from withdrawal Sx if they stop taking a drug
116
Is physical dependence a psycho condition?
NO
117
NOTE
Everyone who is dependent has developed a tolerance, but not everyone w/ a tolerance is dependent.
118
List the depressants
alcohol
119
List the hallucinogens
- LSD
- Marijuana
120
List the stimulants
- Caffeine
- Tobacco
- Cocaine
- Amphetamines
121
What do depressants do?
reduce "depress" CNS activity
122
How do low doses of depressants work?
Tend to leave you feeling more relaxed & facilitate social interaction by slightly reducing inhibitions
123
How do mod-high doses of depressants work?
- Induced sleep
- Cognitive & perceptual impairments
- Excessive muscle relaxation (resulting in slurred speech, poor motor coordination, etc.)
- Lightheadedness/dizziness
- Slowed breathing
124
What is one of the most common depressant drugs used today?
alcohol
125
How does alcohol affect GABA?
agonist
126
How does alcohol affect ACh, 5-HT & GLU?
antagonist
127
NOTE about alcohol
- Passes directly into BS via digestive tract (can have quick effects)
- Can alter neural activity in numerous ways, including by binding directly to receptors for ACh, 5-HT, GLU &GABA
128
Withdrawal syndrome ranges from...
from a hangover (i.e. HA & nausea) to delirium tremens (i.e., severe tremors, shivering, irregular HR, hallucinations)
129
Alcohol can cross placenta, potentially resulting
fetal alcohol syndrome
130
What are hallucinogens?
drugs that alter one’s awareness of reality and/or their own thoughts & feelings.
131
Common examples of hallucinogens
- LSD (aka acid)
- MDMA (ecstasy/molly)
- Psilocybin (magic mushrooms)
- Peyote
- Ketamine
- Marijuana
132
LSD main Sx
hallucinations ("trips")
- incorporate real & imagine stimuli
133
What does LSD bind to?
5-HT receptors, acting as an antagonist for some & an agonist for others
134
What is marijuana made from?
dried leaves & flowers of cannabis plant
135
How is marijuana ingested?
inhaled or oral
136
What is the psychoactive ingredient in marijuana?
THC
137
Describe addition & withdrawal w/ marijuana
- low potential for addiction
- withdrawal is rare
138
What other categories does marijuana fall into & describe action?
depressant
- due to lowering certain kinds or neural activity
stimulant
- due to incr other kinds of neural activity
139
Social doses of marijuana can cause...
- Incr sense of well-being
- craving sweets
- enhanced sensations
- delayed rxn time
- incr thirst/appetite
140
Higher doses of marijuana can cause...
- Impaired judgment
- paranoia
- short-term memory impairment
- possibility of hallucinations (rare)
141
THC mimics?
anandamide
142
Describe anandamide.
an endogenous substance that helps slow movement/incr sense of calm & remove unnecessary short-term
memories
143
Which breaks down quicker, THC or anandamide?
anandamide
144
Psychoactive drugs that generally yield an effect due to an incr of CNS activity are known as...
stimulants
145
What is the main sx of stimulants?
speeding up both physical & mental bodily processes
146
Common examples of stimulants.
- Caffeine
- Tobacco (nicotine)
- Cocaine
- Amphetamines (including ecstasy & meth)
- “Bath salts” (a wide mix of specific stimulant street drugs)
147
Caffeine give a feeling of "wakefulness" due to...
caffeine binding to adenosine receptors
148
What is adenosine?
an endogenous chemical that accumulates throughout the day & leads us to feel more tired the more it binds to neural receptors.
149
How are caffeine & adenosine related?
Caffeine mimics adenosine & binds to those same receptors, blocking adenosine from having those effects.
150
What is the psychoactive ingredient in tobacco?
nicotine
151
Nicotine acts as...
an agonist for certain ACh receptors
152
NOTE
- Nicotine is highly addictive
- can also incr NE activity & sympathetic nervous system activity (linked to elevated arousal/stimulation)
153
Continued use of nicotine can lead to...
desensitized ACh receptors, where more of the drug is needed to produce the same effect
154
Teratogenic effects of nicotine
Incr likelihood of miscarriage, stillbirth & early death of child
155
Describe cocaine/crack.
a stimulant made from coca shrub.
156
Describe how cocaine/crack works.
- Acts by blocking reuptake of numerous neurotransmitters, including DA, NE & 5-HT
- results in a higher [] of these in their synapses
157
Psychological effects of cocaine
- excessive confidence
- high energy levels
- being extra talkative
- feeling fidgety
- loss of appetite
158
Chronic use of cocaine can lead to...
the CNS to expect higher DA levels (in particular) to feel its typical rewarding effects
159
What are the most commonly abused stimulants?
amphetamines
160
Which amphetamine is particularly addictive?
Meth
161
NOTE
amphetamines have similar effects as cocaine, but w/ a slower onset & longer duration
162
Chronic abuse can lead to psychotic sx like...
- paranoia
- hallucinations
- erratic behavior, etc
163
Example of opioids
morphine, codeine & heroin.
164
Describe opioids.
- highly effective analgesics, but very addictive
- act on receptors in the brain that normally bind to endogenous opiates (endorphins)
165
What are some addictive effects of opioids?
rush of pleasure & drowsy euphoria
166
Withdrawal syndrome of opioids occurs w/n how much time of last dose?
hours
167
What are the Sx of withdrawal syndrome from opioids?
- constipation
- pupil constriction
- reduced libido
168
What may help treat heroin addictions?
Methadone & buprenorphine replacement therapies
169
Define Hazardous/risky substance use.
Consuming more of the drug than is recommended, which may put you at risk for developing adverse health effects
170
Define substance use disorder?
An actual DSM-5 dx in which repeated psychoactive drug use is causing “significant impairment or distress”
171
Dx of substance use disorder relies on...
both abuse & physical dependence to be present
172
Describe the definition of addiction?
- word origin denotes “enslavement”
- user is no longer able to self-regulate consumption of a drug
173
Does genetic play a role in addiction?
YES
174
What are some psychological & social factors can also incr risk of addiction?
- substance availability & cost
- Socioeconomic factors
- Racial & ethnic disparities
- Traumatic experiences
- Hx of mental health disorders
175
NOTE
Drugs that reach the brain quickly **&** act on the brain’s “reward circuits” (often DA pathways) are typically those that are easiest to become addicted to
176
Describe the progression of addiction
Initial drug taking-->
Habitual drug taking-->
Drug craving & repeated relapse
177
Describe physical-dependence theories
- Cycle of use is driven by avoiding withdrawal Sx
- Tx: Withdraw drugs in hospital setting (still see relapse)
--> I need/have to take it
178
Describe positive theories
- Motivated by (+) drug effects
- Crave (+) properties
--> it makes me feel good
179
Describe incentive-sensitization theory
- Addicts crave drugs more but enjoy them less
- Must take more to get the same high, so dose increases over time
180
Name to the 2 pathways that are a part of the mesotelencephalic dopamine system.
- Nigrostriatal pathway
- Mesocorticolimbic
181
What are specific areas of targeted in the nigrostriatal pathway?
from substantia nigra to dorsal striatum
182
Degeneration of the nigrostriatal pathway is associated with what condition?
Parkinson's Disease
183
Describe the mesotelencephalic dopamine system do?
a collective circuitry that **reinforces behavior**
184
What are specific areas of targeted in the mesocorticolimbic pathway?
ventral tegmental area to cortical & limbic areas
185
Which pathway mediates self-stimulation?
mesocorticolimbic pathway
186
Dopaminergic input to this structure is critical to experience reward & pleasure.
Nucleus accumbens
187
The nucleus accumbens is responsible for
reward & pleasure
