Exam 1 Flashcards
first candidate for the “seat of the mind”? Why? (2)
- heart
- heart rate increases during many emotional situations
- damage to heart = death
- damage to brain = not necessarily death
famous philosopher that proposed that the heart was the seat of the mind?
Aristotle
famous pholisopher who lived from 460-370 BC and claimed that brain was the seat of the mind?
- “from the brain come joys, delights, sorrows, etc.”
Hippocrates
What was trepanation? Why was it done? what does this tell us? what time period?
- drilling a hole in the skull
- thought to alleviate migrains, mental disorders, seizures, etc
- they saw a connection between brain and mental processes
- 1400s
with what two scientists did the scientific study of the brain begin? explain what each did
- time period?
- Andreas Versallius - first to draw a complete atlas of the brain
- Da Vinci - also did drawings of brain
- 1400s - 1500s
Descartes’ view on relationship between mind and body? How do they interact?
- time period?
- Dualism: body is made of material substance and mind is made of immaterial substance
- mind interacts with body through a hydraulic system of tubes connected to pineal gland (thought to not be bilateral). “Mind/soul” resides in those tubes/cavities
- 1600s
Explain what Paul Broca discovered
- what did this prove?
- damage to a certain area (thereafter deemed ‘Broca’s Area’) caused impairments in language production
- the mind is grounded in the brain. Damage to a certain portion of brain = specific impairment.
What did Luigi Galvani discover? How?
- time period?
- The brain interacts with the body through electric signals
- delivering current to an exposed nerve on a frog makes frog nerve contract
- 1700s
When did the neuroscientific revoluntion begin? what caused this?
- 1980s
- dramatic breakthroughs in medical technologies . Noninvasive live brain imaging allows us to see live brain activity.
what are the two types of cells in the nervous system?
- neurons
- glia
neurons are units of what?
- work in?
- essence of?
- do they last? regenerate?
- brain function
- large networks
- plasticity
- yes, longevity. But they DON’T regenerate.
function of glial cells? - do they regenerate?
- support, nourish, insulate, and repair neurons. W/O these, neurons wouldn’t work.
- YES
formal definition of neuron
cells in the nervous system that communicate with one another to perform information-processing tasks
approximately how many neurons are in the brain?
100 billion
function of the cell body
coordinates information-processing tasks and keeps the cell alive
functions of the dendrites
receive information from other neurons and relay it to cell body
what are dendritic branches?
branches off of dendrites (DUH)
what are dendritic spines? what do they do?
- little bulges on dendrites
- they increase surface area of dendrite so dendrite to reach more neurons
axon function
transmits information to other neurons, muscles, or glands
what is the axon hillock? what occurs here?
- where axon emerges from soma
- the AP starts here
what is a collateral?
any bifurcation in an axon (any place where axon splits)
what’s the myelin sheath?
insulating layer of fatty material around axon
what’s found w/in the soma?
nucleus
2 portions/extensions of dendrites
- dendritic branches
2. dendritic spine
4 portions/extensions of axons
- hillock
- collateral
- axon terminal (end branches)
- terminal buttons
all neurons are _____
interconnected
what are synapses?
connections through which neurons communicate
generally, info from neuron to neuron is what?
uni-directional
Each neuron can be activated and do what?
fire an AP when it reaches a threshold potential
2 different types of synapses. Explain what they do.
- Excitatory - increases the likelihood that the target neuron will fire
- Inhibitory - decreases the likelihood that the target neuron will fire
nodes of ranvier involved in what?
propagation of electric impulse
myelin is made of?
glial cells
size of:
- soma?
- axon?
- synapse?
- 10 micrometers
- millimeters to a meter
- 20 nanometers
what are the three types of neurons
- sensory neuron
- motor neuron
- interneuron
what do sensory neurons do?
- polarity?
receive info from the external world and convey it to the brain via the SC
- bipolar or unipolar
what do motor neurons do?
- polarity?
carry signals from the SC to the muscles to induce movement
- multipolar
what do interneurons do? - polarity?
connect sensory neurons, motor neurons, and other interneurons
- multipolarity
study and know what polarities of different neurons look like - presentation 2 slides 21 - 24 and notes in notebook
STUDY
list the 5 steps of a basic circuit for an arc reflex
- Receptor: a sensory neuron/cell that transforms external energy into electrical energy (the nervous impulse)
- Sensory Neuron
- Interneuron
- Motor Neuron
- Effector: cell that transforms the nervous impulse into an external response (muscle, gland, or organ)
what is the reflex arc?
causes the body to react to external stimuli quickly - the info doesn’t have to travel all the way to the brain. it bypasses the brain and goes through the SC.
practice labeling on slides 27 and 28 of Presentation 2
practice
what are ions?
small electrically charged molecules that flow in and out of the cell
what are membrane channels?
gates that open/close letting some molecules pass in/out of the neuron
what generates the membrane potential?
unequal concentration of ion charges across the semipermeable membrane
define resting potential? what are human’s resting potentials? explain what this means
electrical potential of a neuron in the absence of stimulation
- -70 mv
- inside of the neuron is more negative
what are the major ions that are part of neuron potentials? explain their concentration
- Na+ (more outisde)
- K+ (more inside)
define threshold potential
- what value is it?
the point at which an AP fires
- -50mv
excitatory stimulation makes what more likely?
- how does it do this? what’s this called?
makes the neuron more likely to generate an action potential
- brings the potential closer to -50mv. The intracellular side becomes LESS negative.
- depolarization
inhibitory stimulation makes what less likely?
- how does it do this? what’s this called?
makes the neuron less likely to generate an AP
- makes the intracellular side MORE negative
- hyperpolarization
where does the AP start?
axon hillock
action potentials follow what principle?
- aka a ____ signal
all or nothing
- digital
What happens during an action potential?
- voltage-gated ion channels open
- there’s a quick and large reversal of membrane polarity
study action potential picture on slide 2 of communicating information within a neuron
study
the AP propagates down the axon like what?
like a wave
3 properties of a nerve impulse once it’s fired
- it cannot invert direction
- preserves the same magnitude
- propagates till the axon terminal
there’s a _____ frequency that a neuron fires at, but?
baseline
- but when it’s stimulated, the firing rate increases
with APs, transmission is _____ based, but with synaptic transmission, transmission is ____ based
electrically, chemically
explain what happens with the presynaptic and postsynaptic cells during synaptic transmission
Pre:
1. AP reaches terminal button
2. Synaptic vesicles filled with NTs are released
Post:
1. NTs activate receptors on the post-cell
2. inhibitory of excitatory potential
3. IF threshold is reached, AP
Is neurotransmitter release all or nothing? Explain
- what’s this called?
NO
- you can release a little of a NT or alot
- analogical
list the steps in the flow of info from neuron 1 to neuron 2
- dendrites
- cell body
- axon
- NT
- synapse
- dendrites
- cell body
- axon
what’s the key-lock mechanism mean?
each NT has a specific receptor
main role of acetylcholine
involved in voluntary MUSCLE CONTROL
- also, memory, regulation of attention, sleeping, and dreaming
what is dopamine associated with?
- regulates what?
REWARD
- motor behavior, motivation, pleasure, and emotional arousal
what to remember about glutamate?
it’s the most common EXCITATORY NT in the brain
- information transmission throughout the brain
what to remember about GABA
it’s the most common INHIBITORY NT in the brain
- STOPS firing of neurons in brain
role of norepinephrine?
influences mood and arousal
role of serotonin?
regulates sleep and wakefulness, mood, eating, and aggressive behavior
many drugs affect the nervous system by doing what?
increasing, interfering with, or mimicking the manufacture of NTs
what do agonists do?
- explain this simpler
they increase the action of a NT by mimicking it or blocking the reuptake of it
- bid to a specific receptor well enough to make it work (close enough fit to make it work) OR stops it from being taken up from the synapse
give 3 examples of agonists
- L-dopa for dopamine
- amphetamine and cocaine for NE and DA
- SSRI for serotonin
what is L-dopa used for?
relieving PD symptoms
explain when and how SSRI works
- with depression, there’s often abnormally low levels of serotonin. SSR1 prohibits the reuptake of serotonin so it stays in the synapse longer
what are antagonists?
- explain simpler how this works
drugs that block the function of a NT
- like a key that fits in the lock but doesn’t open the door
example of an atagonist and how it’s used
curare for Ach
- used as a poison: occupies the receptors for Ach - paralyzes voluntary muscles and muscles involved in memory, not blocking sensory info at all
give two examples of toxins that block the AP that are not neurotransmitters
- explain what they do
- TTX - blocks NA+ channels
- small amount knocks out neurons involved muscles control - TEA - blocks K+ channels
- similar effects to TTX
define brain plasticity
the capacity for the brain to be molded by experience
all of the NS is involved in ___ and ____
- info is stored as a pattern of what?
memory and learning
- synaptic change
ultimatley, what is learning?
changing the connectivity of neurons due to experience = plasticity
Massive plasticity when? But?
early in life
- it continues throughout life
during childhood, there is a _____ of synapses
- so what happens?
- synapses are ruled by what principle?
an overproduction
- synapses compete for activity
- use it or lose it principle: weak synapses regress, strong synapses strengthen
synaptic activity is determined by what?
- explain this
ENVIRONMENT
- what you’re personally exposed to determines which synapses are strengthened (ex/ you ski and don’t snowboard - skiing synapses are strengthened and snowboard ones are pruned)
why is synaptic pruning a good thing?
- give ex/
because you’re getting rid of connections that aren’t used to make the ones that ARE used more effecient
- get rid of skills you’ll never need and specialize in the ones that you’ll need
- lemur video
the cerebral cortex occupies ____% of the volume of the brain
80
- what is the hindbrain made up of?
- medulla
- pons
- cerebellum
what structures it the brain stem comprised of? name them low to high
medulla, pons, midbrain
Forebrain aka?
cerebrum
diencephalon comprised of?
thalamus and hypothalamus
3 functions of the spinal cord
- transmit motor info from CNS to body
- transmit sensory info from body to CNS
- control basic reflexes that don’t need brain
location and function of cerebellum
- side of brainstem
- coordination of movement and fine-tune muscle control
overall functions of the brainstem
- specifically, medulla
basic vital functions
- medulla: breathing, HR, BP, digestion
function of thalamus
main relay station of CNS - All incoming sensory info will stop here, integrate with other info, and keep going
which sense bypasses the thalamus?
SMELL
function of the hypothalamus
master gland regulating many basic functions with the endocrine system; HOMEOSTATIC regulation; hunger, thirst, temp, sex
2 functions of the 4 ventricles
- mechanical support: cushion brain
2. to exchange substances with tissue of brain - nutrients to neurons and collect waste
list the subcortical structures
basal ganglia, hippocampus & amygdala (these 2 are parts of limbic system)
major functions of basal ganglia
motor performance and control of complex cognition (types of memory)
structure affected in PD
- less ___ with PD?
basal ganglia
- dopamine
major function of hippocampus
MEMORY
major function of amygdala
emotional states
damage to amygdala can cause what?
an inability to learn fear
neocortex composed of how many layers?
- these layers ____
6
- vary from region to region
name and describe the location of the three sulci we need to know
- Longitudinal fissure: divides brain into 2 hemispheres
- Central sulcus: defines border between frontal and parietal lobes
- Lateral sulcus: defines border between temporal lobe and parietal and frontal lobes
list the FIVE lobes
- frontal
- parietal
- temporal
- occipital
- limbic
this structure makes us special when compared to other animals, makes us the highest functioning creatures
frontal lobe
4 regions/structures that are in the frontal lobe
- primary MOTOR cortex
- pre-motor cortex
- Broca’s area
- pre-frontal cortex
most posterior part of the frontal lobe? function of this region?
primary motor cortex
- controls voluntary movement
Broca’s area function?
language production, fluency
what lobe is responsible for executive function? what portion of this lobe? Define/explain EF
- frontal
- pre-frontal cortex
- alotting brain resources to certain functions (ex/ am i going to talk now or listen); problem-solving, planning, inhibition
structure impaired in phineas gage?
frontal lobe
in children, this lobe is much less developed. what does this cause?
frontal lobe
- inability to inhibit certain behaviors (ex/ grab piece of cake from someone)
parietal lobe contains what cortex? where?
primary somatosensory cortex, most anterior gyrus in parietal lobe
list 4 functions of the parietal lobe
- primary somatosensory cortex (receives incoming sensory info)
- spatial orientation and perception (multi-modal integration) - ex/ watch a movie and combine visual and auditory info, then put the voices in space, firgure out which person the voice is coming from.
- comprehension of language
- control of attention
what does topological organization mean?
map-like organization of body parts on the sensory and motor cortexes of the brain
explain topological organization
the primary motor cortex and somatosensory cortex each have specific portions that correlate to a specific body part
2 properties of topological map
- DISTORTED representation: over-representation of more sensitive areas of the body
- CONTROLATERAL representation: ex/ if my left hand is touched, the RIGHT side of my somatosensory cortex is activated
explain the phantom limb phenomenon and what causes it
- what does this tell us?
- person still perceives a limb as present and painful even though it’s gone
- face area invades the hand area that’s no longer receiving any input, causes him to feel the phantom limb when his face is stroked
- brain is hungry for connections. If there’s an unused are of the brain, connections will form and rewire. Example of plasticity.
4 areas/functions of temporal lobe
- primary auditory cortex - first area of brain to receive auditory info
- Wernicke’s area - language comprehension
- learning and memory - medial temporal lobe (that’s close to hippocampus)
- Higher-order processing of visual info
2 areas of occipital lobe
- primary visual cortex
2. visual association cortex
what makes up the limbic system?
the limbic lobe, the hippocampus, and the amygdala
3 functions of the limbic lobe
- emotional responses
- memory
- drive-related behavior/motivation - eating, drinking, temp control
what’s the corpus callosum?
a thick band of nerve fibers that allows the two hemispheres of the brain to talk to each other
study case studies on last PP
study
