BioPsyc Chapter 3 Flashcards
NFL tie in
Easterling and Duerson - concussions → progressive brain damage → suicide
How many nerve cells in the brain
100 billion
Define Neurons
NEurons - cells in the nervous system that communicate with each other to perform information processing tasks
What did Cajal do
Golgi stain to see the three parts of the neuron
Define the Cell body
Cell body (soma) of neuron - coordinates processing of info/keeps the cell alive - contains the nucleus
Define Dendrite
Greek - tree - receives info from other neutrons & relays to cell body
Explain Axons
Axons - carry info to the neutrons, muscles, glands - very long up to 1 m - from spinal cord to toe; Dendrite-INBOX - AXON-OUTBOX
Define Myelin Sheath
myelin sheath covers axon - fatty material composed of glial cells
Define glial cells/ functions
Glial cells support cell in nervous syst. 1 - digest parts of dead neurons 2 physical/nutritional support for neurons - 3 form myelin
Demyelinating diseases
multiple sclerosis - myelin sheath deteriorates - slows neuron transmission ie loss of feeling overcome
Define Synapse + how many
junction between axon of one neutron and the dendrites / cell body of another - 100-500 trillion synapses in adults - info transmit across synapse = neuron communication
Sensory Neurons
Receive info from the external world-conveyed to the brain and spinal cord i.e. In eyes-sensitive to light
motor neurons
signals to muscles produces movement
interneurons
Connect sensory neurons, motor neurons, othe interneurons - MOST COMMON
specialized neurons example
1 purkinjie cells - info from cerebellum 2 pyramidal cerebral cortex 3 bipolar cells - eyesight
how fast do signals travel in the body
25-200 kPH
Explain Hodgkin and Huxley’s contribution
studied giant quid axons -found difference in charge inside + outside = resting potential
Electrochemical Action
1 conduction - signal within neurons - dendrite → cell body → axon 2 transmission - movement of signals of synapse = Electrochemical Action
Resting Potential
- difference in electric charge in/out of Neuron’s cell membrane - arises from difference in [ion] - more K+ inside → so they move out - leave (-70Mv) charge inside; Resting Potential = potential energy - creates place for possible elec. impulse
Depolarization
Normally K+ flows out and Na+ blocked from going in - but in Depolarization → Na+ flows IN to axon - makes it less negatively charged
what is Action Potential
The electric impulse - Action Potential - an electric signal conducted along length of axon to synapse - “all or none” - not enough stimulation = none, enough = consistent; from loss of K+ and flow of NA+ in = the process
Refractory period
time after action potential when new action potential CANNOT be initiated - reversed to start by chemical pump - NA+ back out - K+ back in
Average firing limit (from refractory period)
30-500 times/sec
Intensity of stimulus changes THIS:
of neurons firing - frequency of individual neurons DOES NOT change action potential
what is Saltatory conduction
charge jumps through myelin to “nodes of Ranvier” - domino effect - speeds the flow of concentration
Terminal buttons
Like structures that branch out from the axon
neurotransmitters
In vesicles-chemicals that transmit info across the synapse to receiving dendrites
Why are neurotransmitters short-lived
One drift away 2 inactivated by enzymes 3 removed through a re-uptake
Receptors
Of the cell membrane to receive neurotransmitters-initiate or prevent new electric signal
Presynaptic neuron
Sending neuron where the message comes from
explain synaptic transmission
Neurotransmitters float across the synapse - bind to receptor sites - Communication, thoughts emotion
Nero transmitter prevalence
Different types for different places
Three-stepSynapse process
One reuptake-Nero transmitter is reabsorbed by presynaptic neuron’s axon 2 enzyme deactivation-transmitters broken down 3 auto receptors-detect excess -stop flow
Acetycholine (ACh)
Neurotransmitter ACh - many functions ie voluntary motor - no ACh = botulism paralysis also Alzheimer’s death
Dopamine
transmitter Dopamine - regulates motor behaviour, pleasure, aruosal - role in addiction, high levels = schizophrenia, low levels = parkinson
Serotonin
transmitter - regulation of sleep, eating, aggressive behaviour - low levels = mood disorders - Porzac slows release - more useful less reuptake
Orexin
transmitter - eating, sleep
Glutamate
transmitter - excitatory in brain - enhances info transmission - too much = seizures
GABA
gamma-aminobutyric acid - primary inhibitory transmitter - stops firing puts glutamate in check
Norepinephrine
transmitter - danger vigilance
Endorphins
transmitter - pain pathways/emotion centers “runner’s high”
What all those neurotransmitters do
normal functioning needs a delicate balance of each - imbalances CAN occur naturally - or drug induced
FACT: Electric charge of the action potential takes the form they can cross the synaptic gap
FACT: 60 -100 chemicals are neurotransmitters
FACT drugs mimic neurotransitters
FACT drug use affects brain function
Agonists
drugs that INCREASE the action of a neurotransmitter
L-Dopa
(agonist) L-Dopa treats Parkinsons - increase Dopamine - works less well over time ? Michael J Fox
Amphetamine-Cocaine Combo
Agonists Amphetamine - releases norepinephrine/dope; Cocaine - prevents norep/dope reuptake= FLOODS synapse=increased receptor activation = euphoria+energy - can lead to heart attack
Prozac
relieves depression - Serotonin reuptake inhibitor - Agonist
Clonidine
Agonist - Clonidine binds to autoreceptors - prevent their inhibitory effect
nicotine
agonist - binds to post-synaptic receptor sites - activate = increased neurotransmitters
Antagonists def
Antagonists BLOCK funciton of neurotransmitter vs Agonists increase func
Caffeine/Botulinium
Antagonists - they activate autoreceptors - inhibit release of neurotransmitters
Beta-blockers
Antagonists - ie propanalol - block transmitters from binding on post- synaptic receptors
Meth
affects pathways for dope, seortonin, etc - antagonist
Endocrine system
glands that secrete hormones
Define nervous System
network of neurons - convey electrochemical info throuought the body
CNS
Central Nervous System - brain + spinal cord
Peripheral Nervous System
Connects CNS to organs/muscles
Somatic Nervous System
conveys between VOLUNTARY MSUCLES / CNS
Automatic Nervous system
controls involuntary organs ie blood vessels heart 2 Subs: 1 sympathetic 2 parasympathetic
Sympathetic Nervous System + Example
prepares body for action against threat ie danger alley - pupils dilate, heart rate faster
Parasympathetic NS
undoes sympathetic, returns body to normal resting state
Symp + Parasymp Control
they coordinate many functions ie sexual behaviour - anxiety disrupts this balance
Spinal Cord functions
beathing, moving, etc - puts higher processing to action
Spinal reflexes
no brain instructions needed for basic responses/ contractions
Spinal injury + superman
where the injury occurs = damage done ie Chris Reeve superman
Brain weight
3 pounds - simpler funcitons @ lower levels
Hindbrain
continuous with the spinal cord - coordintates info in/out of spinal cord
Hindrain Structures
Medulla, reticular formation, cerebellum, pons
Medulla
extension of spinal cord into skull - heart ratte, circulation, respiration
Reticualr Formation
regulates sleep, wake, arousal
cerbellum
“little brain” fine motor skills
Pons
bridge - relays cerbellum info to rest of brain
Midbrain
small in humans - 1 tectum, 2 tegmentum
Tectum
orients an organism to environment ie swivel @ sound
Tegmentum
movement and arousal - mood from here
Forebrain
highest level - cognitive/emotional - ovverrides other parts in humans
Cerebral cortex
outermost layer - visible - 2 hemis
Subcortical structures def + list
subcortical - udner cerebral cortex near center - protected (between ears) 1 Thalamus 2 Hypothalamus 3 Pituaitary Gland 4 Limbic System 5 Basal Ganglia
Thalamus
relays info from SENSES - transmit to cerebral ie seeing/smelling apple
Hypothalamus
regulates body temp - hunger,thirst, sex - under thalamus
Lesions @ hypothalamus
some lead to overeating - no appetite - electric stimualtion can make cats bite
Pituitary Gland
master gland - hormones that direct other glands - ie breastfeeding releases oxytocin
Limbic System
hpyothalamus, hippocampus, amygldala: motivation, emotion, learning, memory - subcorts meet cortex
Hippocampus
seahorse - new memories then integrates into knowledge network for cortex storage ie damage- cant remember conversation
Amygdala
tips of hippocampus (almond) - emotional memories ie haunted house
what do the Basal Ganglia do
intentional movements and posture
Parkinsons + Basal Ganglia
damaged so intentiona lmvmts not working - substantia niagra neurons damaged
Gyri + Sulci
ridge on cerebral cortex - sulci = depressions - fold up cerbral cortex
Brain organization across hemispheres
left/right - symmetrical in appearance
Contralateral controls
right hemisphere from left side body, left hemi from right side body ie contralateral vision
commisures
bundles of axons - make communication possible btwn parallels areas of the cortex in each half
corpus callosum = commisure #1
large commisure - connects large areas of cerebral cortex on each side of the brain - supports communication acroos hemis - so right stuff registered in left half
Organization WITHIN hemispheres
Lobes : Occipatal lobe, parietal lobe, temporal lobe, frontal lobe
Occipatal lobe
processes viual info - contains primary visual cortex
Parietal Lobe
process touch - somatosensory cortex - strip of tissue from top of brain down sides - represents skin areas contralateral surface of bod - homunculus - image showing somatsoensory importance - Motor cortex - another strip for movmtn
Temporal Lobe
responsible for learning/lang - PRIMARY AUDITORY CORTEX like others
Frontal lobe
specialized areas for mvmt, abstract thinking, planning, emmory, judgment - HUMANS
association areas
areas of cerbral cortex - provide sense + meaning to the info - neurons here more flexible - can be shaped by learning ie noises ? meaning
Mirror Neurons
active when seeing behaviour ie handshake
Marc dax
lateralization of brain 1936 left/right
Paul Broca
Aphasias - Broca’s area - Monseiurg Leborne - “tan”
Aphasias
braind dange defects
Expressive Aphasias
individuals understand what they hear but CANNOT answer
Receptive Aphasias
recpetive (wernicke’s ) aphasias - individuals cant express meaning in speech/ understand
Explain cerebral cortex hemispheric specialization
Left: analysis, right side mvmt, speech ,writing; RIGHT spatial construction, face recognition, non-verbal images, left side mvmt
Evidence of brain lateralization
perceptual assymetry - info in right visual field (to LEFT brain0 analyzed more cuz left goes to right side - EEG Patterns
Explain Brain Plasiticity
sensory cortices adapt to changes in environment - ability to be modified ie Phantom Limb syndrome due to this
Benefits of brain plasticity
ie better motor cortex for musicians, taxi drivers, etc specialization - physcial excersise stimulates hippcampus
Is the brain perfect?
No - brain is not perfect - so NOT like enchanted loom philosphers thought
Explain CNS development in embryo
4th week 3 levels visible 5 th week forebrain.hindbrian subs, subs foldi n on each other
Explain Brain ontegeny
ontogeny - how brain develops in individual - 8 weeks - structures done - other species much slower
explain evolution of CNS from other species
Protozoa - molecules trigger cilia - Flatworms - first CNS - humans = best
Explain HUMAN brain evolution
forebrain is refined - evolved quickly than other species - primates to human time also rapid
Explain Nature/nuture
Nature - genetics vs nurutre environment - focus has shifted to determine interaction of the 2
Explain genes + chromosomes
Genes = section of DNA , Chromosomes = threads of DNA - 22 pairs are autosomes - 23rd pair = sex chromosomes, XX in females, XY in males - Karyotype = representation of human chromosomes
Explain degree of relatedness
probs of sharing gnees - identical twins from split egg = 100% - dizogtic twin like all siblings 50% - monozyg twins higher chance of same disease
Explain epigentic
environmental influences that determine if genes are expressed & degree of expression - Does NOT alter DNA
Epigenetic marks
chemical modifications to DNA - turn genes on / off from environmetn
Genotype vs phenotype
genotype - inherited genes - phenotype - observable traits
consequences of the fact that genes come in pairs
alleles - homo/hetero - dominant, recessive so recessive allels only seen in homozygous offspring
Define DNa methylation + example
DNA methylation - adding methyl group to DNA - works as epigentic mark “epigenetic writer” - swticdhes genes on/off ie nurses high/low stress different methylation
Histone Modification
another source of epigentic marks - chemical to histones involved in packagin DNA
FACT - Genetic capabilites deffer with your individual capabilities
FACT: intelligence can be inherited - extraversion less so
Heritability + ratio
measure of variablitiy of traits accounted for by genes - ratio = 0-1.00 - high inheritance = 1.00
Heritabiltiy of humans
Moderate Range 0.3-0.6 - not all intelligence is genetics
3 genetic disorders in humans
1 PKU (phenylketonuria) - single recessive gene on autosome - treated with special diet 2 red-green colour blindness - recessive trait by X chromosome so sex-linked 3 Huntington’s disease - Woody guthrie
4 heritability points
1 its an abstract concept - not specific genes 2 - pop concept not inidividuals 3 dpeendent on environment 4 Not fate
explain licking & grooming effect
more LG = chilled out adult rats, less = high strung rats
Why study damaged brain
To understand normal operation
Explain Broca / Wernicke Areas
Broca’s aea = spoken language, left frontal lobe Wernicker’s area - lang. comprhension - upper left temporal lobe
Phineas Gage
railroad work - pole through frontal lobe -quiet before now a irritable MF
Split brain research + examples
Sperry , also Gazzinga, normal - info comes In and shared between hemis - split brain to treat epilepsy- info goes to left hemi and stays there ie could speak but could pick it up ( in left but not right)
Split Brain chimeric face example
Brad&Leo - can answer leo cuz right side seen by left speech brain, point to brad, cuz left hand controlled by right seeing brain (contralateral vision)
Hubert + Wiesel
mapped visual cortex - cortrast between light/dark areas - - has feature detectors - repsond to certain aspects of image
EEG Electroencophalograph
EEG records electrical activity in brain- ie awake vs sleep
List 2 neuroimaging techniques
1 structural brain imaging - basic 2 functional brain imaging - shows activity of tasks
Explain strucutral brain imaging methods
1 CT computerized axial tomopgraphy - xrays 2 MRI - magnetic resonance - line up nuclei of molecules - then snap back into place - the energy scanned - good for soft tissue - 3 DTI diffusion tensor imaging - maps connectivity with pathways of water molecules
Functional brain imaging techniques
1 PET scan (positron emission tomography) radioactive substance into bloodstream while tasks - harmless\ 2. fMRI - detects difference between oxy/deoxy hemoglobin when exposed to magnetic pulses
fMRI over Pet advatages
- no radiaoctive exposure 2 localizes change across BRIEFER periods
what network does functional imaging show when subject at rest
default network
insights from functional imaging
fusiform gyrus - Phineas gage - PET confirms different areas activated when listening
Why cant fMRI be used to validate courtroom
fMRI results averaged - not just single individual
Define brain death
irreversible loss of all brain functions
Why use transcranial magnetic stimulation
cant ethically do brain damge - but can mimic with TMS
Define transcranial magnetic stimulation +_ visual cortex example
activates/deactives cortex with mmagnetic pulse = temporary damagee ie motion dtectin damaged on visual cortex so CONC: visual cortex causes mtoion perception
Explain fMRI TMS combos
TMS to mimic brain damge -fMRI to see where its occuring
List 3 Brain myths
1 10% used 2 toddler stimuli dievolop brain 3 different learning types
Heritabiltiy equation
find it online
