Midterm 1 - Unit 4, Biological Bases of Behavior Flashcards

1
Q

Neurons and its structure

A
  • cell of the nervous system specialized for sending and receiving neural messages
  • 100 billion, making over 100 trillion connections
  • dendrites, cell body/soma, axon, axon terminals/terminal branches, and myelin sheath
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2
Q

Action potentials

A
  • The way neurons talk to each other, by firing off action potentials
  • generated at the junction between the axon and cell body
  • then move down the length of the axon
  • When a neuron is depolarized by sufficient input, it reaches a threshold for producing action potential, this is called voltage threshold
  • at peak of action potential, interior of cell more positively charged than outside
  • action potential is all or nothing, not stronger or weaker
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3
Q

Resting potential

A
  • neuron is at rest, more negatively charged particles inside cell, the imbalance between intracellular and extracellular fluid results in an electrical charge across the membrane (70 millivolts)
  • neuron cannot fire action potential at this resting tate
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4
Q

Depolarization

A
  • happens when the ions outside of the cell want to get through to the inside and the ion channels open up
  • this movement causes the electrical charge across the membrane to begin to reverse
  • polarize means far apart, depolarize means less far membrane, so this means that the extracellular and intracellular environment is decreasing
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5
Q

Voltage threshold

A
  • When a neuron is depolarized by sufficient input, it reaches a threshold for producing action potential
  • once it’s reached, these voltage gated ion channels just open wide, positively charged sodium ions come flooding in from outside
  • once threshold is reached, the action potential is inevitable
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6
Q

repolarization

A
  • At peak of action potential, additional channels open up that allow for another type of ion, potassium ions, to move across membrane
  • they move from inside cell to outside, and negative direction comes out again
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7
Q

Refractory period

A
  • after action potential, at the end of repolarization, there is a temporary dip below resting potential, this is the refractory period
  • at this period, it is hard to get neuron to fire again
  • this period ensures that action potential is propagated forward, bc action potential moves like a wave along the axon
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8
Q

Synaptic cleft

A
  • At the end of axon, when the action potential (the electrical signal) reaches its end, the neurons don’t actually touch each other
  • They are separated by the synaptic cleft
  • electrical signals are unable to jump over this cleft so they are converted into a chemical one, neurotransmitters
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9
Q

receptor

A
  • channel in membrane of a neuron that binds neurotransmitters (receives it from the neuron across)
  • binds neurotransmitters in lock and key fashion, where only a certain neurotransmitter can bind to a certain receptor
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10
Q

Intracellular fluid and extracellular fluid

A
  • watery chemical soup
  • contains various electrically charged particles, or ions
  • intracellular (inside the cell)
    extracellular (outside cell)
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11
Q

myelin sheath + glial cells = support neuron functioning

A

Myelin sheath makes signals travel faster.
Glial cells support, protect, and help neurons work properly.

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12
Q

Excitation

A
  • receiving neuron slightly depolarized
  • excitatory currents are those that prompt one neuron to share information with the next through an action potential
  • moves the neuron closer towards voltage threshold and increases likelihood of action potential
  • excitatory inputs contract muscle
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13
Q

Inhibitation

A
  • receiving neuron slightly hyperpolarized
  • moves the neuron further from threshold and reduces likelihood of action potential
  • while inhibitory currents reduce the probability that such a transfer will take place
  • inhibitory inputs tell muscles to relax
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14
Q

GABA

A
  • A type of neurotransmitters within a class of it
  • GABA is within amino acids
  • Binds to major inhibitory receptors; influences muscle tone
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15
Q

Acetycholine

A

A class of neurotransmitters

  • Binds to both inhibitory and excitatory receptors; contributes to muscle control
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16
Q

Norepinephrine

A

Under monoamines, which is a class of neurotransmitters

  • Involved in fight-or-flight response activation
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17
Q

Serotonin

A

Under monoamines, which is a class of neurotransmitters

  • Contributes to feelings of happiness and well-being, appetite, and sleep
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18
Q

Dopamine

A

Under monoamines, which is a class of neurotransmitters

  • Associated with reward and pleasurable experiences
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19
Q

Endorphines

A
  • Under neuropeptides, which is a class of neurotransmitters
  • “endogenous morphine”
  • promote feelings of pleasure and reduce pain
    codes for opioid receptor where endorphins bind
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20
Q

Psychoactive drugs

A
  • chemical substances that alter a person’s thoughts, feelings, or behaviors by influencing the activity of neurotransmitters in the nervous system
  • Psychoactive drugs are artificial chemicals introduced into the body that “piggyback” onto the preexisting infrastructure used by your body’s own neurotransmitters.
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21
Q

Agonists & antagonists

A

Agonist:
- enhances action of a neurotransmitter
- by increasing release, block its reuptake or mimicking neurotransmitter and activating its postsynaptic receptor

Antagonist:
- inhibits actions of a neurotransmitter
- by blocking release, destroying neurotransmitter in synapse, binding to a postsynaptic receptor to block neurotransmitter

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22
Q

Opioid addiction

A
  • psychoactive drugs don’t just bind for a short period of time and then leave, if used for long time, they can change existing infrastructure that they’re hijacking and overpower reward function of endogenous opioids
  • repeated use causes changes to receptor structure
  • loss of sensitivity for naturally occurring rewards
  • Repeated exposure to opioids alters the brain so that it functions normally only when the drugs are present and abnormally when they are not, resulting in addiction.
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23
Q

Nervous system

A
  • complex network of nerves (bundles of neurons) that controls and regulates all bodily functions
  • subdivided into central nervous system and peripheral nervous system
24
Q

nerves

A
  • bundles of neurons
25
Q

peripheral nervous system

A

Consists of two parts: somatic nervous system and autonomic nervous system

26
Q

somatic nervous system

A
  • carries voluntary commands from the central nervous system to the muscles, controls our deliberate movements
  • brings sensory input back to central nervous system CNS
27
Q

autonomic nervous system

A
  • carries involuntary commands to organs, blood vessels, and glands
  • operates outside of our conscious control
  • divided into sympathetic and parasympathetic branches
  • autonomy = independence
28
Q

endocrine system

A
  • network of glands that release chemical messengers - hormones - into the blood
29
Q

pituitary gland

A
  • called the “master gland,” regulates other glands, director of them
  • regulates hunger, sexual arousal, growth, sleep, and even navigation of your social world
30
Q

oxytocin

A
  • produced by the hypothalamus, released into the blood stream by the pituitary gland
  • plays important role in social bonding
  • Vole experiment: Intranasal oxytocin increases trust, generosity, cooperation, emotion recognition, empathy, more positivity, less conflict
  • HOWEVER, effects of oxytocin agonism in humans are not always consistent
  • Some studies found no effects, or even negative/antisocial effects
  • Sometimes, oxytocin actually amplify the distrust in ppl with very high levels of dispositional distrust
  • One hypothesis: may make social information more salient but subsequent behavior will depend on the filters through which you interpret the social information
31
Q

spinal reflexes

A
  • initiated by spinal cord without involvement of the brain, like response to painful stimulus
  • quick reaction is happening at the level of the spinal cord, signal doesn’t have to reach the brain in order to respond to danger
  • reflex near a hot stove
  • pain receptors detect, electrical signals carry by sensory neurons to spinal cord, interneurons within spinal cord process signal and relay it motor neuron, motor neurons send command to muscles to react
32
Q

medulla

A
  • heart rate, blood pressure, reflexes like coughing and swallowing, involuntary systems
  • heart and lungs - medal goes over your heart and lungs
33
Q

pons

A
  • breathing, speed it up and slow it down when you body needs it
  • relays sensations like hearing, taste to higher levels of the brain
  • pons = bridge, involved in balance and coordination
34
Q

reticular formation

A
  • inside pons and medulla, runs through brainstem into midbrain
  • arousal and attention, wakefulness, being conscious
  • helps filter sensory info, determine which stimuli we should pay attention to
35
Q

cerebellum

A
  • pons, medulla, and cerebellum makes up hindbrain
  • mini brain hanging off main brain
  • coordination, balance, precise fine movements, accurate timing
  • helps refines movement and synchronization from sensory feedback
  • damage here affects the precision and accuracy of movements, but not movement in general itself
  • first area to be affected by alcohol
36
Q

limbic system

A
  • includes hypothalamus, thalamus, amygdala, hippocampus, and basal ganglia
  • all these located under the wrinkly part of the brain
  • known as the emotional brain
37
Q

capgras syndrome

A
  • condition where someone believes that someone close to them has been replaced by an imposter
38
Q

cerebral cortex

A
  • outer most layer of the brain, the wrinkly part
  • divided into left and right hemispheres connected by large bundle of nerve fibers (corpus callosum)
  • further divided into five lobes (frontal, parietal, occipital, temporal + insular lobe) FPOT
39
Q

frontal lobe

A
  • front of brain
  • movement planning, command center
  • contains primary motor cortex and prefrontal cortex
40
Q

parietal lobe

A
  • second part of the cerebral cortex
  • contains primary somatosensory cortex
  • spatial navigation, damage causes us to bump into things
  • pay attention to and locate objects in space
41
Q

occipital lobe

A
  • third section in FPOT
  • vision, right across from eyes
  • contains primary visual cortex
  • links to temporal and parietal lobes, recognize objects and process their movement
42
Q

temporal lobe

A
  • above ears
  • allows you to hear and understand language
  • helps to recognize objects and ppl
  • contains primary auditory cortex and primary olfactory cortex
43
Q

insular lobe

A
  • perceive our inner world
  • perceive the state of internal organs
  • feel heart racing, feel pain, the insular lobe allows you to perceive that
  • contains primary taste cortex
44
Q

primary somatosensory and motor areas

A
  • organized like a map, organized topographically
  • body parts that are physically close are represented in adjacent areas of cortex
  • amount of cortex space corresponds to amount of fine control or sensory discrimination required, does not match on to the size of the body type, bc the size matches to the degree of the sensitivity or finest the body part is used, more sensitive so more representation in brain
45
Q

primary sensory areas

A
  • each lobe has some sort of sensory area
  • parietal lobe: somatosensory area
  • occipital lobe: visual area
  • temporal lobe: auditory and olfactory areas
    insular lobe: primary taste area
46
Q

association cortex

A
  • integrates incoming info from sensory areas with existing knowledge to produce meaningful experience of the world
  • association = connection
  • ties incoming stimuli to past memories, etc
47
Q

corpus callosum, how two brain hemisphere communicate

A
  • bridge of fibers that connect the two cerebral hemispheres
  • helps them talk to each other, or interhemispheric transfer
48
Q

contralateral organization

A
  • BUTeach hemisphere does this for the OPPOSITE side of the body
  • This contralateral organization allows neurologists to assume that someone who cannot feel the right side of their body likely has left-hemisphere brain damage in their somatosensory cortex
49
Q

lateralization

A
  • Some functions of the brain are located on either the right or the left side
  • Areas in the left hemisphere are specialized for language
  • Analogous area in right hemisphere specialized for nonverbal, visuospatial processing of information
  • Evidence from strokes
  • Left hemisphere damage: deficits using & understanding language
  • Right hemisphere: deficits recognizing faces, reading maps, drawing geometric shapes
50
Q

split brain

A
  • Visual Stimulation: If a split-brain patient sees an object in their left visual field (processed by the right hemisphere), they may be unable to name it but can draw it with their left hand. Conversely, if they see it in their right visual field (processed by the left hemisphere), they can name it.
  • Tactile Stimulation: If the patient touches an object with their left hand (processed by the right hemisphere), they may not be able to verbally identify it. If they touch it with their right hand (processed by the left hemisphere), they can name it.
51
Q

broca’s area vs wernicke’s area

A

broca’s
- left frontal lobe

  • Broca’s patients could understand language but could not speak

wenicke’s
- temporal lobe

  • Wernicke’s patients could not understand language but could produce speech (although very jumbled)
52
Q

ways to studying the brain

A

neuropsychology
- Study of brain function by examining functional alterations following brain damage

limitations:
- Naturally occurring brain damage is not specifically localized & may spread over time
- Difficulty generalizing from one person’s brain and behavior to another

brain stimulation methods
- TMS, TDCS
Advantages
- Causal insights into brain function
- Some techniques may have therapeutic potential
Limitations
- Limited spatial precision (particularly TMS & TCDS)
- Limited depth penetration
- More invasive

Methods with good spatial resolution, poor temporal resolution
- PET, fMRI
- Injection of radioactive tracer
- Used to measure brain activity by detecting changes in blood oxygenation

Methods with good temporal resolution, poor spatial resolution
- EEG
- Recording of electrical waves from many thousands of neurons in the brain, gathered using electrodes placed on the scalp

53
Q

Neural plasticity

A
  • brain’s ability to change and adapt throughout individual’s life
  • Critical periods= specific timeframe during development when brain is particularly receptive to environmental stimuli, allowing for larger changes in neural connection
  • study: rats housed in enriched and deprived environments
54
Q

phantom limb syndrome

A

continuing sensation in limb that has been amputated

  • although the finger is gone, its place in the brain is still reserved for some time, so the person’s capacity to feel the finger’s presence remains
55
Q

Damage plasticity

A

neural modification/reorganization following injury

56
Q

critical period

A

Critical periods= specific timeframe during development when brain is particularly receptive to environmental stimuli, allowing for larger changes in neural connections

  • The periods early in life during which very specific experiences must occur to ensure the normal development of a characteristic or behavior.