Chapter 3 Flashcards
Glial cells
Support neurons and neuronal functioning, enhances learning and memory, removes waste, creates blood-brain barrier and myelin sheath, responds to injury
Astrocytes
make up brain blood barrier
Oligodendrocytes
make up the myelin shealth in some axons
Synapse
gap between neurons where info is transmitted
synaptic vessicles
contain neurotransmitters
Dendrites
receive information
Axon
send information to other neurons
Axon terminals
contain synaptic vesicles which release neurotransmitters into the synapse
Soma
cell body, manufactures new proteins/cell components, contains nuclei
myelin sheath
insulates axon and increases speed of electrical transmission
nodes of ranvier
gaps in the myelin sheath
Explain the process of an action potential
when a neuron is stimulated it begins to depolarize due to potassium and sodium diffusing across the membrane. Once membrane potential reaches threshold( -55mV), the neuron fires an action potential. The neuron then repolarizes in order to return to its resting state, but in this process it overshoots and enters a brief period of hyperpolarization before then returning to resting potential.
resting potential
neuron’s resting membrane voltage when it is not firing (typically -70mV)
threshold
The minimum cell membrane voltage to trigger depolarization/ an action potential (-55mV)
absolute refractory period
depolarization/repolarization, cell can’t generate another action potential at this point
relative refractory period
hyperpolarization, action potential can be generated at this time given a large enough stimulus
hyperpolarization
relative refractory period
All or none law
cell either depolarizes or it doesn’t, as soon as cell membrane voltage hits -55mV, it sends the same electrical impluse no matter the strength of the stimulus. The strength of the stimulus is determined by the number of action potentials generated.
neurotransmitters
chemicals that carry messages across the synapse to either excite or inhibit other neurons firing(2 types; excitatory and inhibitory)
Five stages of chemical communication
synthesis, storage, release, binding, deactivation (broken down or reuptake)
graded potentials
excitatory postsynaptic potential (EPSP); postsynaptic depolarization, postsynaptic neuron more likely to fire
Inhibitory postsynaptic potential (IPSP); postsynaptic hyperpolarization, postsynaptic neuron less likely to fire
glutamate
main excitatory NT, sensory and learning
drugs- alcohol and sensory enhancers
GABA
main inhibitory NT
alcohol and anti-anxiety
Norepinephrine
cortex arousal
drugs- amphetamine and methamphetamine
Acetylcholine
cortex arousal, selective attention, memory, muscle contradiction
drugs- nicotine, memory enhancers, botox
Dopamine
motor function and pleasure/reward
drugs- L-dopa(treats Parkinsons), antipsychotics
Serotonin
Mood regulation, aggression, sleep-wake cycles, temperature
drugs- SSRI anti-depressants
Endorphins
Pain killers
drugs- codeine, morphine, heroin
Anandamide
Pain killers, increase appetite
drugs- Tetrahydrocannabinol (THC)
Psychoactive drugs
impact the nervous system
agonist
when a drug enhances activity at the receptor site(either binds to receptor site or blocks re-uptake of NTs)
antagonist
when a drug reduces activity at the receptor site
Neural plasticity
The ability of neurons to change over time. 3 areas:
plasticity over development
plasticity and learning
plasticity following injury and/or degeneration
neural plasticity and development
growth (of dendrites and axons), synaptogenesis (formation of new synapses), pruning (destroying certain neurons to remove pathways that aren’t useful), myelination
neural plasticity and learning
synaptogenesis, potentiation(changing of activation and structure of neurons), structural plasticity (nerons change their shape from standard condition to an enriched condition)
neural plasticity, injury, and degeneration
neurogenesis (formation of new neurons) happens in brain, doctors can inject stem cells (undifferentiated cells that can develop into any kind of cell)
The brain-behaviour network
how different regions of the brain are responsible for different behaviours
cerebral cortex
outer grey matter of the cerebrum
basal gangliafunction and damage consequences
structures in the cortex that help control movements, takes sensory info from primary sensory and association cortexs and sends instructions based on the info to the motor cortex
helps control emotions, language, decision making, learning, and memory
damage can result in Parkinson’s and Tourettes
limbic system
evolved out of olfactory system, closely tied to autonomic NS, bridge between cerebral hemispheres and brain stem, plays are role in emotion, motivation, learning, smell, memory.
4 main areas: thalamus, hypothalamus, amygdala, hippocampus
cerebellum
controls balance and enables us to coordinate movement and learn motor skills
brain stem
midbrain, hindbrain(pons medulla)
spinal cord
connects peripheral NS with brain
protected by vertebrae
reflex arc/spinal reflexes
skin receptor, sensory neuron, inter-neuron, motor neuron, muscle
3 major regions of the brain
forebrain, midbrain, hindbrain
The forebrain
cerebral cortex, basal ganglia, limbic system
the midbrain
helps control eye movement and coordination, contain RAS
the hindbrain
medulla, pons, cerebellum
peripheral nervous system
somatic nervous system, autonomic nervous system
somatic nervous system
contains sensory and motor nerves
voluntary muscle movement
carries info from CNS to the muscles
autonomic nervous system
involuntary muscle movements, 2 divisions: sympathetic, activates functions(fight-or-flight) and parasympathetic inhibits functions(rest-and-digest)
The endocrine system
network of glands that release hormones into the bloodstream
pituitary gland and hormones
controls the other glands in the body
releases oxytocin(love hormone)
adrenal gland and hormones
found above the kidneys releases adrenaline and cortisol during times of stress and arousal
what are the 8 different brain stimulating, recording and imaging techniques?
EEG, MRI. fMRI, PET scan, MEG, CT scan, DBS, TMS
Electroencephalograph (EEG)
measures electrical activity generated by the brain, noninvasive
Magnetic resonance imaging (MRI)
produces high resolution images of soft tissue such as the brain; measure the release of energy from water in reaction to a magnetic field, superior to CT scans, noninvasive
functional MRI (fMRI)
measures change in blood oxygen levels, shows activity in response to the subject looking at something or solving a problem, noninvasive
position emission tomography (PET) scans
functional imaging technique, shows areas of low and high activity, invasive; involves injection of a radioactive drug
Magnetoencephalography (MEG)
measures presence of magnetic fields on the surface of the cerebral cortex
Computed tomography (CT scan)
3D reconstruction
deep brain stimulation (DBS)
surgical procedure that implants battery powered electrodes into the brain to stimulate specific areas
transcranial magnetic stimulation (TMS)
applies quick changing magnetic fields to the skull which creates electrical fields in the brain that either enhances or interrupts brain function
genotype
set of gene transmitted to us at birth from our parents
phenotype
genotype expression
heritability
how much your phenotype is determined by genetics and how much it is determined by environmental factors
multiple sclerosis
degrading of myelin sheath resulting in electrical signals becoming scrambled and leading to emotional and physical difficulties such as difficulties with coordination.
meninges
3 membranes that protect brain and spinal cord
cerebral ventricles
CSF filled pockets that extend through the brain and spinal cord
cerebrospinal fluid
provides nutrients, waste removal, and is a shock absorber
corpus callosum
nerve fibres that connect the 2 brain hemispheres
thalamus
sensory relay center
hypothalamus
maintains bodily states through hormone levels, regulates hunger, thirst, sexual drive, temperature (four Fs)
amygdala
modifies our memories based on how we feel, triggered by fear, helps us pay attention to emotionally impactful stimuli, remember what triggered our emotions, makes sense of social cues
hippocampus
plays a critical role in memory, especially spatial memory ex. mental map, damage can cause trouble creating long term memories ex. remembering events
Reticular Activating system (RAS)
connects with forebrain and cerebral cortex (outer grey matter of cerebrum) plays a key role in waking up, activates cortex by increasing signal-to-noise ratio, damage can cause a coma
parasympathetic nervous system
rest and digest
sympathetic nervous system
fight or flight
Adrenalin
release by the adrenal glands when cued by the sympathetic system, contracts muscles, constricts blood vessels, increases breakdown of fatty acids and synthesis of glycogen into glucose, dilates bronchioles, supresses digestive and reproductive function, dialtes pupils
chromosomes
found in the nucleus, humans have 46, contain genes which are made of DNA which is a set of instructions for making proteins
reaction range
the extent to which genes set limits oh how much a trait can change in response to a new environment
central sulcus
deep groove that separates the frontal lobe from the rest of the cortex
motor cortex
generates signals for voluntary movement
somatosensory cortex
receives data about sensation: touch, pressure, pain
prefrontal cortex
responsible for thinking, planning, and language, contains Broca’s area; which plays a key role in language production
association cortex
Regions of the cerebral cortex that analyze/ reanalyze sensory inputs to build up our perceptions
ADHD drugs
boost the signal-to-noise ration in the prefrontal cortex
frontal lobe
responsible for motor functions, planning, language, decision making, contains motor and prefrontal cortexs
parietal lobe
eye movements, lobe specialized for touch and perception(tracking objects location, shape, orientation), relays visual/touch info to motor cortex,contains somatosensory cortex
temporal lobe
lobe specialized in hearing, plays a role in understanding language and memory
contains auditory cortex and Wernicke’s area(plays a critical role in understanding speech)
lateral fissure
separates temporal lobe from the rest of the cortex
occipital lobe
contains visual cortex, dedicated to seeing
pons
connects the cortex to the cerebellum
medulla
involved in basic functions such as heart-rate, breathing, vomiting
6 parts of the CNS
cortex, basal ganglia, limbic system, brain stem, cerebellum, and spinal cord
electrical stimulation studies
pioneered by Wilder Penfield, investigated brain functions by electrically stimulating the brain during neurosurgery, supported the idea that neural communication is electrical
