unit 2 Flashcards
function of dendrite
receive incoming messages
function of cell body (soma)
contains nucleus
function of myelin sheath
fatty tissue that INSULATES axon speeding up transmission of messages
functions of node of ranvier
space between myelin sheath
function of schwann cells
non-neuronal cells in CNS that form myelin sheath
function of axon
longest part of neuron which the electrical message travels the length of neuron
function of axon terminal buds (buttons)
end point of a neuron that relates neurotransmitters into the synapse, hence sending the message onto next neurons
what is resting potential
neuron not firing, has negative charge with mostly potassium ions (K) inside & sodium (Na) outside which creates a polarized neuron
what ions are inside and outside during resting polarization, what is this also known as, and what is the neuron at
potassium inside + sodium outside; aka polarization; homeostasis
what is action potential
“nerve impulse”
causes the neuron to fire (electrical pulse travels length of axon)
all-or-nothing principle, maintains intensity
what is the all or nothing principle
when the nucleus decides to fire, it fires down axons completely or not at all
what is depolarization
when message begins, sodium (Na+) ions come in & depolarize (neutralize) section of axon (causing potassium ions to rush out)
what is the refractory period
potassium (+K) ions are pushed out and neurons “paused to reload”; during this time a neuron is unable to fire
how does the action potential work
- sodium channels open + sodium ions rush in
- potassium channels open + potassium ions rush
- sodium channels close, but channels further down open causing the process to go to the length of the axon
what sends to the neuron
terminal buds
what receives the messages
dendrites
what are neurotransmitters
chemical substance that crosses synapse to carry on message to next neuron
what is the synapse
open space between 2 neurons at which neurotransmitters cross
what do the receptor sites
specific points on dendrites of neurons that receive specific types of neurotransmitters
what is reuptake
the reabsorption by a neuron of transmission following the transmissions of a nerve impulse across a synapse
acetylcholine role + associated disorders
muscle contractions, memory and learning; Alzheimer’s disease
dopamine role + associated disorders
movement, thought process, rewarding sensation + pleasure; Parkinson’s (-), Schizophrenia (+), Drug Addiction (+)
serotonin role + associated disorders
emotional states, sleep + happiness; depression (-)
norepinephrine role + associated disorders
physical arousal, learning + memory; depression & stress (-)
GABA role + associated disorders
inhibition of brain activity, calming drug; anxiety disorders (-)
endorphins role + associated disorders
positive emotion, runners high, pain perception; opiate addiction
what are agonists and what is an example
imposter (mimics neurotransmitters)
fits into receptor site like a master key + notes
ex: morphine - opiate derivatives, mimics endorphins
what are antagonists and what is an example
blocker (blocks neurotransmitters)
fits in receptor site in fake key which prevents the neurotransmitter from working
ex: botox blocks acetylcholine
what does peripheral nervous system include
sensory motor neurons that connect CNS to rest of the body;
autonomic, somatic, sympathetic, parasympathetic
what does CNS include
spine + brain in the center of the body + interneurons
brain function
control center
spinal cord function
super highway of nerves;
body’s means of transmitting messages to or from brain
interneurons function
only neurons in CNS
“relay neuron”
messenger between sensory and motor
sensory [afferent] neurons function
carries incoming messages from sense receptors to CNS (feeling)
motor [efferent] neurons function
carries outgoing info from CNS to peripheral nervous system + muscles
autonomic nervous function
controls involuntary functions or things that happen autonomic
ex: breathing, heartbeat, digestion, etc.
somatic nervous function
controls voluntary movements + communication to and from sense organs; WE CONTROL
sympathetic nervous function
physically arouses the body and preps it to react in stressful situations expending energy
flight or fight
inhibits digestion
stimulates glucose release by liver
release of epinephrine + norephrine by adrenal gland
dilates pupils
parasympathetic nervous system
calms body, conserves energy + helps keep a constant internal state
rest + digest
stimulates digestion
contracts pupils
slows breathing + heart rate
what system does our endocrine system work with in normal circumstances
parasympathetic NS
what system does our endocrine system work with in crisis circumstances
sympathetic NS
endocrine system’s hormones are ____
released into and circulate thru the bloodstream; received ONLY at a specific site
pituitary gland function
master gland
directed by hypothalamus
thyroid gland function
produces hormone thyroxine which stimulates chemicals important to all body tissues
adrenal gland function
releases epinephrine and norephrine — which help ppl generate extra energy to deal with difficult situations
pancreas function
regulates blood sugar levels with insulin [glucose]
gonads function
sex glands
maintains reproductive organs in adults to produce sperm and eggs
testes - releases the hormone, testosterone
ovaries - release the hormones estrogen and progesterone
hormones vs neurotransmitters
h : longer, affects long term and goes long dist. thru blood
n: shorter, short term, short dist. across synapse from neuron to neuron
cerebral cortex
performs sophisticated info processing + has lobes & cortices
corpus callosum
functions to connect 2 hemispheres of brain
sum = add 2 parts
hippocampus
learning + new memories
campus = place to learn
thalamus
sensory switchboard
takes all incoming sensory info and directs it to connect lobes in cerebral cortex
** smell goes to olfactory bulb
hypothalamus
5fs - fight, f*ck, fever, flight, feeding
amygdala
fear stress + aggression [fight or flight]
cerebellum
little brain
movement, balance and coordination
“you must be my cerebellum bc i can’t stand without you”
pons
controlling sleep cycle and breathing
“pondering when you are sleeping”
medulla
controls heart beat
reticular formation
attention
limbic system includes
hypothalamic nuclei, amygdala, hippocampus, corpus callosum, thalamus
how are brain lesions used to study the brain
experimentally destroys brain tissue to study behaviors after such destruction
usually done for scientific or medicinal purposes
how are EEGs used to study the brain
electroencephalogram
simplified recording of the electrical waves sweeping across the brain’s surface
measured by electrodes placed by scalp
[FUNCTION]
how are pet scans used to study the brain
position emission tomography
process used to observe metabolic processes in the body + brain
patient ingests a radioactive form of glucose and PET takes pictures of it being used in body/brain
[FUNCTION]
how are MRIs used to study the brain
magnetic resonance imaging
uses magnetic fields + radio waves to produce computer-generated images that distinguish among different types of brain tissue
[STRUCTURE]
how are fMRI used to study the brain
measures brain activity by detecting changes associated with blood flow
patient interacts w/ info during scan to show activity
[FUNCTION]
how are CT/CAT used to study the brain
computerized tomography
combines + series of x-rays images to allow taken from different angles that create cross-sectional images of body + brain (3D x-rays)
[STRUCTURE]
frontal lobe case study and function
personality
phineas gage - steel rod thru skull damaged frontal lobe
motor cortex
what is motor cortex responsible for
voluntary movements
parietal lobe function
control body position, touch, pressure, temp + pain
sensory cortex
what is sensory cortex responsible for
perceiving touch + pressure on parts of body
temporal lobe function
hearing, strong long term memory, speech + understanding
auditory cortex
occipital lobe function
vision
broca’s area
areas in left frontal lobe that directs muscle movements involved in speech
what does broca’s aphasia mean
hard to speak
wernicke’s area
area in left temporal lobe that is involved in language compression + expression
what does wernicke’s aphasia mean
can’t understand, no meaning
left vs right hemispheres
L: logic + language
R: creative, non verbal, faces
brain neuroplasticity
you don’t use it you don’t lose it
split brain operations is done by splitting the
corpus callosum & right visual field = L hemisphere and viceversa
psychoactive drugs
a chemical substance that alters perceptions + mood (effects consciousness)
tolerance
continued use of drug
dependence
absence from drugs may lead to physical pain, intense cravings [physical dep], negative emotions [psychological dep]
withdrawal
upon stop taking a drug (after addiction) users may experience undesirable effects of withdrawal
depressants
“downers”
drugs that reduce neural activity + slow body functions
alcohol, barbiturates (depresses CNS activity), opiates (highly addictive)
stimulants
“uppers”
drugs that excite neural activity + speed up bodily functions
caffeine, amphetamines, cocaine
increased HR BR & attentiveness, mental awareness, anxiety, restlessness
hallucinogens
drugs that distort perceptions + evoke sensory images in absence of sensory input
LSD - bad trips, flashbacks
Marijuana (THC) - impaired attention, slowed reaction
what is the role of expectations in drug use?
impacts response to intoxications
what is the circadian rythm
controlled by hypothalamus
light signals to tell pineal gland to stop release of melatonin and dark doesn’t signal to increase melatonin
25 hours
stages 1-3 are known as
NREM
stage 1 sleep
mix of alpha + theta waves
drifting to sleep
may experience images or auditory hallucinations
stage 2 of sleep
mainly theta waves
sleep spindles : short bursts of energy occur
clearly asleep + relaxed
stage 3 of sleep
delta waves [deepest sleep]
significantly slowed brain activity
hard to awaken
only occurs first few cycles of night
REM sleep
low amp, regular beta waves
rapid eye movement + vivid dreams
body relaxed but brain active
sleep cycle repeats itself about every___?
90 mins
how many sleep cycles do we have each night?
4-6 sleep cycles
can we make up for the amount of sleep missed
no
sleep deprivation symptoms
difficulty focusing
diminished productivity
more likely to make mistakes
diminished immune system
hallucinations (usually after 72 hours)
insomnia
difficulty falling asleep
narcolepsy
overpowering urge to fall asleep midst conversation or standing up
sleep attacks are usually 5 mins or less
sleep apnea
failure to breathe when asleep
usually in overweight people
treated with weight loss and CPAP
effect:
lack of REM bc they don’t go thru sleep cycle
night terrors
sudden arousal from sleep > intense fear accompanied by psychological reactions
not same as nightmare bc you cannot remember this in the morning generally
usually during 1st sleep cycle (NREM)
sleepwalking
blank state, slow movement, may try to eat or go wrong place (stage 3)
rem behavior disorder
muscle not paralyzed in REM allowing person to act out in dreams
usually violent + vivid
more often in older middle aged men
why do we sleep theories
- protection
- recuperates (restores + repairs brain function)
- helps remembering (restores + rebuilds fading memories)
- sleep growth (pit. gland releases growth hormone)
what are dreams
usually story-like unfolding mental images
some degree of likeness to daily activities
what does the wish fulfilment theory say?
Sigmund Freud suggested that dreams provide a safe place for our unconcious wants + desires
manifest content vs latent content
manifest - literal story & latent - underlying meaning of dream
info processing in dreams
dreams help us sift, surf and fix day’s experiences in memories
activation synthesis theory
states that brain engages in a lot of neural activity that is random which dreams makes sense of
(dreams are brain’s interpretation of own activity so they mean nothing)
cognitive development in dreams
some researchers argue that we dream as a part of our brain maturation and cognitive development
what do all dream researchers believe?
we need REM sleep
what is rem rebound?
when deprived of rem sleep, and we then sleep, we show an increase in rem sleep
