Chapter 2: Brain and Neural Communication Flashcards
Sensation
Physical information that the environment is receirved by any of the body’s senses.
The direct INTERACTION with physical energy in the world.
Perception
the cognitive interpretation of a sensation
What is Phrenology?
the study of intense brain mapping. Franz Gall believed that personality could be mapped on the brain and that specific part of the brain corresponded to self esteem, negativity, hope, etc.
The lobe associated with language and memory, taste and smell functions
temporal lobe
the ____ lobe is involved in planning, organizing, impulse control and sends commands
the frontal lobe
the parietal lobe functions
touch and spatial awareness, kinesthetic sense; bodily awareness
what is kinesthetic sense
bodily awareness, awareness of your position relative to the floor
the ____ lobe is involved with visual processing
occipital
How many layers comprise the meninges? Describe
3 layers:
1) Dura Mater: tough outer layer
2) Arachnoid membrane: thin sheet of tissue , below this membrane is where CSF circulates
3) Pia Mater: inner layer that is connected to the brains surface.
Where does CSF circulate?
in the subarachnoid space of the meninges. the subarachnoid space is between the arachnoid membrane and the pia matter.
Ventricles
hollowed out areas of the brain where there is no tissue. The CSF flows in the lateral ventricles and the cells that line the ventricles is the site of CSF produciton
site of CSF production
the cell lining of the ventricle.
the CSF flows in the _____ ventricles
lateral ventricles.
T/F The CSF circulates down the spinal cord and back up into the brain
true
Functions of the CSF
1) protection
2) carries out waste products from brain
T/F CSF can carry oxygen to the brain
false. only blood does
t/F CSF is constantly being made and disposed of
true. there is a high regeneration rate of CSF. The CSF continues to be made in the ventricles.
In terms of surface features of the brain, what is a gyrus?
the “bumpy” crests of the frontal cortex
in terms of surface features of theb rain, what is the sulcus?
the valleys of the frontal cortex
What is a fissure?
a large sulcus
longitudinal fissure
a large sulcus that splits the brain in half into the two hemispheres
T/F: Brain areas with high activation receive higher blood flow
true
How does the blood brain barrier protect the brain?
it protects the brain from larger pathogens that may be present in the blood. the pathogens are unable to flow past the barrier, only small nutrients like oxygen or glucose could make their way into the brain cell.
If the blood brain barrier ruptures, blood may _____, triggering a ____
blood may flow into the brain and make direct contact with the brain cells, triggering a stroke.
hemorrhagic stroke
when blood gets into the brain and causes apoptosis of cells and increase pressure in the brain. Due to a ruptured blood vessel.
ischemic stroke
blood cannot flow all the way around the brain due to blockage, there is no oxygen going to a specific part of the brain due to lack of blood flow. causes cell death
blood blockage = ____-stroke, vessel rupture = ____ stroke
blood blockage = ISCHEMIC -stroke,
vessel rupture = HEMORRHAGIC stroke
In terms of locations of the brain, what does lateral mean?
lateral: outside parts og the brain, left or right, FURTHER from the midline. (longitudinal sulcus/fissure)
In terms of locations of the brain, what does medial mean?
towards the midline, in the middle of the brain
anterior
front
posterior
back
doral
on top of head
ventral
on the bottom of the head
3 different ways of anatomical orientation
1) coronal section: frontal view, as if youre looking towards the front.
2) horizontal section: looking from the DORSAL view, from ontop of the brain
3) Saggital section:: looking from the SIDE VIEW, as if you cut the brain down the longitudinal fissure, the MEDIAL view
the 2 cerebral hemispheres are connected by the ______ and separated by the ____
the 2 cerebral hemispheres are connected by the CORPUS CALLOSUM and separated by the LONGITUDINAL FISSURE
the _____brain is responsible for complex behaviors and cognitive processes, while the ___brain is responsible for unconcious behaviors (sleep wake cycle).
the FOREbrain (CEREBRAL CORTEX) is responsible for complex behaviors and cognitive processes, while the MIDbrain and BRAIN STEM is responsible for unconcious behaviors (sleep wake cycle).
thalamus location and function
dead center in the brain near the ventricles. Acts as a relay station.
Pia matter
thin membrane encapsulating the brain, ppart of the meninges
cerebellum
fine motor technique and refinement
t/F: basic structure of human brain retains the most basic features of the less complex mammalian brains
true (we have the same brainstems and midbrains)
how can you primarily tell you’re looking at the human brain
the human brain is characterized primarily by the size and MASS of FOREBRAIN. We retain similar brain stems and midbrains as other species.
T/F: the larger the animal, the larger the brain
true
What part of the brain is associated with higher intelligence?
higher IQ= associated with more developed cerebral cortex.
If elephants have larger brains than us, why are we smarter than elephants?
although they have larger cortical SIZE, our brains are smaller but MORE DENSE with neurons. we have a LARGER NEURONAL MASS for the size of our brain. (ex/ or cortex is a dense cake, but the elephant’s cortex is cotton candy)
elephants have larger but less dense neurons, humans have smaller neurons that are more interconnected.
3 reasons as to why humans are smarter compared to other mammal
1) smaller neurons but in high density with more connections
2) larger and more developed forebrain.
3) larger relative cortical volume compared to body mass.
T/F: all mammals have the same size neuron
false. larger animals typically have larger neurons. Humans have smaller neurons but a lot of them, whereas elephants have larger neurons but not as many.
CNS is comprised of
the brain and spinal cord
the PNS is comprised of
neurons, sensory connections, and nerves outside of the CNS
2 components of the PNS
somatic and autonomic
2 components of the autonomic nervous system
sympathetic and parasympathetic.
Why do more complex neurological problems require more advanced measurement techniques rather than just measuring at the sensory level?
there may be damage to the brain (ex/ occipital love) rather than the extremity itself (the eyeball is fine)
ex/ seeing spots of light or blinddness in one or both eyes may be due to a stroke.
Visual Agnosia
an inability to recognize objects or forms.
T/F: visual agnosia stems from malformed retina that create images that are improperly fomed
false. people with visual agnosia have perfectly fine eyes (unless they are near/far sighted), but they cannot recognize objects becuase of TEMPORAL LOBE DAMAGE. there is a problem with PERCEPTION, not sensation.
Prosopagnosia
inability to recognize a face.
The most accurate method of studying the brain. When is this good to use?
histological techniques; allows you to exame the tissue and neuronal loss. the problem is that the person must be dead to do this sort of analysis.
Good approach to use to understand damage from brain diseases.
Who pioneered Brain Stimulation?
Wilder Penfield.
How does brain stimulation work?
use electrical current at DIFFERENT DEPTHS to induce or inhibit a specific behavioral response while subjects are awake.
DBS?
Deep Brain Stimulation. Electrodes are implanted deep in the brain; stimulation of a target area with LOW VOLTAGE ELECTRICAL current to facilitate behavior
how can DBS be used clinically?
can be used for Parkinson’s or epilepsy.
T/F: DBS uses medium to high voltage currents in order to elicit deep brain stimulation
false. uses low voltage.
procedure in which a magnetic coil is placed over the skill to stimulate the underlying brain in order to produce behavior
transcranial magnetic stimulation.
T/F: Transcranial magnetic stimulation is less invasive than DBS
True. DBS requires surgical implantation of electrodes in the brain.
_____ detects changes in blood flow
PET scan
T/F A pet scan produces an image after an event occured
FALSE. PET scans can produce a dynami, real-time measure.
how does a PET scan measure changes in blood flow?
by measuring the changes in the uptake of O2 or glucose
T/F: a PET scan requires a radioactive tracer
true
How does fMRI work
measures oxygen levels in blood flow, and changes in the oxygen content of the blood alter the magnetic properties of the blood.
How do activated brain areas “stand out” in a picture produced by fMRI?
the amount of oxygen in an activated area causes the brain region to stand out magnetically
What does NIRS stand for? What does it work?
NIRS: Near infrared spectroscopy. Oxygenated blood stands out and causes a color change. Infrared light can track the color change depending on O2 use, allowing for visualization of blood flow.
Con with NIRS
it is limited to outer part of the cortex visualization.
on a CT or MRI scan, the corpus calloseum will appear ___
white, because it is filled with myelin.
3 types of dynamic brain imaging
1) positron emission tomography
2) functional magnetic resonance imaging
3) near-infrared spectroscopy.
(also DBS and TMS)
3 types of static imaging technique
1) CT SCAN
2) MRI
3) Diffusion tensor imaging
why is it called a “dynamic” brain imaging technique?
because those techniques can be done when a task is being done by a participant.
computerized tomography (CT) scan uses an ____ beam
xray beam to pass through the brain at many different angles, creating many different images.
how does an MRI work?
produces a 3D image of a brain by passing a strong magnetic field through the brain.
does CT or MRI produces a more clear image?
the MRI produces a better image.
How does DTI work? What is DTI typically used for?
detects the directional movements of water molecules in the brain. Used to identify abnormalities in neural pathways.
Who proposed that the nervous system was composed of a network of interconnected fibers?
Camillo Golgi, thought the nervous system was a “nerve net,” and that the smallest unit is LARGER than a cell
Santiago Ramon y Cajal proposed the _____ hypothesis
the Neuron Hypothesis: that the nervous system is made of discreet cells. The brain is just made of billions of cells.
Camillo Golgi created the ____ which allowed visualization of the first neurons, which actually proved Cajal’s neuron hypothesis
the golgi stain
_____ are electrical impulses used to signal other neurons
Action potentials.
____ allows us to communicate information from our surroundings almost instantaneously
action potentials
Hans Berger
invented the first EEF was measured electrical activity in the brain. Determined that electrical activity in the brain forms different wave patterns.
3 basic subdivisions of the neuron
1) dendrites: receives signals from other cells and receives small graded potentials
2) soma: contains the nucleus and organelles
3) axon, where electrical signals are propagated down
the gap between one neuron and another neuron
synapse
direction of information flow in a neuron
1) dendrite
2) cell body
3) axon
4) synapse+postsynaptic dendrite
cations involved in neural cells? Anions?
cations: K+ and Na+
anions: A- and Cl-
two types of gradients involved with keeping the neuron in equilibrium
concentration and voltage gradients
the voltage difference is greatest ____ to the membrane
close to the membrane. the opposite charges will line up across the membrane.
white matter vs grey matter
white matter is composed of myelinated axons, grey matter is composed of cell bodies with no myelin. Some blood vessles.
at resting potential, the inside of the neuron is ____ relative to the outside.
negatively charged.
Which cation exists primarily inside the neuron?
K+. movement of Na+ into the cell is restricted by gated channels.
How does the neuron regulate the amount of Na+ and K+ inside the membrane?
the sodium-postassium ATPase pump. Pumps 3 Na+ out, 2K+ in, maintains a more negative interior and more K+ inside the cells.
How does Hyper Polarization happen?
occurs after an action potential due to K+ efflux because the potassium voltage gated channels are still open.
2 methods that hyper polarization can occur
1) due to K+ efflux
2) due to Cl- influx (via a neurotransmitter)
how does the neuron get equilibrated back to resting potential after hyper polarization
due to Na+-K+ pump and K+ leak channels.
How does depolarization occur?
due to an influz of Na+ through Na+ channels. Enough depolarization can induce an action potential ( needs to reach threshold first)
When the inside of the neuron reaches the most positive voltage (at the peak of the actionpotential), what channels open? What channels close? During the refractory period, what channels are open?
the Na+ channels close, and the K+ channels open. During refractory period, the K+ voltage gated channels are still open.
All or None Law
the nerve impulse travels down the length of the axon in only ONE DIRECTION with the same intensity
when AP hops from each node of ranvier to another across the axon, this method of propagation is referred to as:
saltatory conduction; it is much faster than traversing across the entire neuron because there is less material resistance.
Why is the refractory period so important?
it ensures that the AP signal is propagated forward and cannot excite channels that were previosuly excited.
T/F: the Action potential is due to Na+K+ ATpas
false. Na+ K+ Atpas maintains resting potential. Ap is due to voltage gated channels that allow ions (NA+) to flow freely into the cell down its concentration gradient.
Neurotransmitters are released by the _____ neuron from vesicles in the ______, and received by the ____ neuron on _____ sites.
Neurotransmitters are released by the PRESYNAPTIC neuron from vesicles in the AXON TERMINALS, and received by the POSTSYNAPTIC neuron on RECEPTOR sites.
____ are used as ligand triggers for voltage change in the post synaptic neuron
Neurotransmitters.
generally, an excitatory neuro transmitter does what?
makes the post synaptic neuron become more positive and increases the likelihood of an action potential
generally, an inhibitory neurotransmitter does what?
it makes the post synaptic neuron become more negative, and decreases the likelihood of an action potential
which neurotransmitter is most associated with movement and attention
acetylcholine
which neurotransmitter is most associated with sleep facilitation and brain activity inhibition?
GABA
which neurotransmitter generally is involved in the hippocampal long term potentiation athway and excites the nervous system?
glutamate
which neurotransmitter is involved both in memory and attention as well as sleep and mood regulation
norepinephrine. Its not gaba, although GABA helps with sleep regulation, it does not play a role in memory; in fact, it reduces memory
which neurotransmitter is involved with mood and appetite
serotonin
which neurotransmitter is involved in reward seeking behavior, control of movement, and cognition and attention?
Dopamine
4 main sensations in which we receive information about the world
1) body sensation (touch and balance)
2) auditory sensation (hearing)
3) visual (light)
4) chemical sensation (taste and olfaction)
How does touch elicit an Action potential?
displacement of hair on the arms causes mechanoreceptor channesl on dendrites to open allowing an influx of Na+. The Na+ influx from the mechanoreceptor channels brings the nerve cell to threshold, eliciting an action potential by activating voltage gated channels.
T/F: Brain electricity shuts down when asleep
false. the brain electrical activity is never silent, even when asleep or comatose.
How does an EEG work?
it measures the summed GRADED POTENTIALS from neurons and reveals features of the brains electrical activity across different regions.
What does Single Cell Recording do?
it measures the brain’s electrical activity by using very thin electrodes placed next to cells or inside them. It can help influence neuronal firing and has been used to treat parkinson’s disease. It’s kind of like a form of Deep Brain Stimulation.
