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You and Your Brain - Harvard University

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You and Your Brain - Harvard University
Created by Lindsey Reichheld
Walpole High School
Enter
Welcome to you and your
brain.
You will be navigating through a presentation on your
brain. The major parts and functions, how your brain is
protected, how your brain changes, and how your
choices affect your brain FOREVER. You will be
guided through some portions of this adventure but you
will have the freedom to choose in other parts. If you
choose to visit a web site just remember to return to
this presentation minimize the internet and this
presentation will continue. Good Luck
continue
Choose
Wisely
Brain Parts &
Functions
Built in
Security
Brain
development
Brains
need
Your brain, your life, your
choices!
What the heck’s a
neurotransmitter
Parts & Functions of the Human
Brain
Parietal Lobe
Click on the parts of the
brain to to learn more about
the function.
Frontal Lobe
Occipital Lobe
Corpus Callosum
Temporal Lobe
Brain Stem
Check out 3-D Brain Anatomy for more parts & more functions!
Cerebellum
Main Menu
Frontal Lobe
•Found under your forehead.
•Center of reasoning, planning,
some parts of speech, movement
(motor cortex), emotions, and
problem solving.
Return to brain parts
Parietal
Lobe
•Found on the top of your head.
•Receives sensory input from the
skin. (touch, pressure,
temperature, & pain)
Temporal Lobe
•Found on the sides of your head
above your ears.
•Functions include speech
perception, hearing, some types
of memory
Return to brain parts
Occipital Lobe
•Found at the back of your head.
•Receives input from the eyes
•Often referred to as the visual
cortex
Return to brain parts
Cerebellum
•Found at the at the back of your
head under the cerebrum.
•Means “little brain”
•Responsible for movement,
balance, posture.
•Often takes over learned
activitiesLike riding a bike!
Brainstem
•Most basic part of your brain.
•Controls functions essential to life
(breathing, digesting, eliminating
waste, sleeping, maintaining body
temperature…)
•Maintains life without “thinking”
Return to brain parts
Corpus
Callosum
•This is located centrally
between the left and right
hemispheres of your brain.
•It is a bundle of fibers that
connects the left and right
hemispheres.
• It is believed this area is
involved in creativity and
problem solving.
Click here to find out more about split brains!
The protection of your Brain
• Your brain sits inside your
skull which protects it from
physical damage.
•The cranium is the part of your
skull that surrounds the brain.
•The cranium is made up of 8
bones that have fused together.
(When you were born the bones had not
yet fused)
Protecting your brain -From the
inside
The skull protects your brain from
physical damage but what about damage
from the inside-like bacteria or viruses?
Your brain is protected from the internal
environment of your body by the blood brain
barrier (BBB). Blood is responsible for moving
materials around your body. You do not want
all of these materials to have access to your
brain. So the outside of the blood vessels in
the brain are made of cells that are VERY
tightly packed together. These cells prevent
large, unwanted molecules from entering the
brain. Unless they are lipids - then they easily
pass through.
Main Menu
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Illustration by Lydia Kibiuk, Copyright
© 1999 Lydia Kibiuk.
Brain
Development
At birth you had the majority of all the neurons that make
up your brain! But your brain only weighed about
400grams. By now your brain weighs1300-1400 grams.
What accounts for the huge change in weight?
This picture shows
how neurons
change overtime
by growing in size.
Neurons continue
to make new
synapses
(connections to
other neurons)
throughout your
lifetime.
Click here to
see what an
infant “sees”
QuickTi me™ and a
T IFF (Uncom pressed) decom pressor
are needed to see t his pict ure.
Image from: Dr. Venkatesh Murthy, Harvard University. “Synapses: from vesicles to circuits” 7/12/05
The Teen
Brain
The high school students (14-18yr) brain are still growing
and developing. In fact these years are not only crucial
to development but explain why teenagers think
“differently” than adults.
What a teenager chooses to
spend his/her time doing will
affect what neuronal
connections are kept. The
pathways in the brain that
are used are those that are
kept. So someone who
spend a lot of time in front of
the T.V. or video games will
be forging very different
pathways than someone
who is active or spend time
reading, or is well balanced
in activities.
http://www.time.com/time/covers/1101040510/brain/
The Teen
Brain
These images show how the brain
matures from the ages of five to 20.
(Keep in mind each individual can be
slightly different) The red/yellow
colors indicate more gray matter
while the blue(s) indicate less gray
matter and a more mature brain.
?
Click here to find out what
the big deal about gray
matter is!
NIMH/UCLA Project Visualizes Maturing
Brainhttp://www.loni.ucla.edu/~thompson/DEVEL/PR.html
The Teen
Brain
During the teen years several parts of the brain finish
developing.
•The frontal cortex goes through a growth period around 12 years, then continues
to fine tune the connections. (pruning)This is the judgment area of the brain and
does not finish developing until about 20 years of age.
•The Corpus Callosum - the fibers that connect the two sides of the brain thicken.
•Cerebellum -recently scientists have thought this area changes a lot during the
teen years.
•The Amygdala - found near the Corpus Callosum develops quickly and is where
emotions are centered. Many teens rely on this center before the frontal cortex is
Click here to see an
fully developed.
experiment showing
what part of the brain
Teens use to process
emotion
Main Menu
What Matter?
The neurons of the nervous system are often divided into two
general categories. White Matter and Gray Matter. (The names
indicate the color of that type of tissue.)
White Matter
Gray Matter
• White in color due to myelin sheath.
• Gray/red in color due to the lack of
myelin sheath.
• Generally responsible for carrying
information
• Generally responsible for processing
information. (Nerve impulses are
generated here.
Image from: http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg
What a brain wants, what a brain
needs
Your brain cells use two times as much energy compared to other somatic (
Your brain cells receive their usable energy from mitochondria
(just like other cells). Remember that mitochondria utilize
glucose to make usable energy. So your brain NEEDS
glucose!!
So your thinking that pop tart and soda you had for breakfast was a good idea?
WRONG! Too much sugar at once is BAD and will actually cause a depletion in the
amount of sugar available to the brain. You are better off having complex carbohydrates
(fruits, veggies, & whole grains) and forget the processed sugar.
What about water? Remember that
you’re your cells are mostly water.
What would happen if any cell lost
water? -Simple it will not function
properly. The same is true for your
brain cells.
Click here to
find out more
about
dehydration.
Don’t forget about
oxygen! Brain cells begin
to die with in minutes of
being deprived of oxygen.
Main Menu
Your Brain, your Life Your
Choices!
Click on your choice of topics to find out how
choices YOU make affect your brain.
Sports
Why should I care?
Sleep
Exercise
Drugs
Diet
Alcohol
Main Menu
Sport
While there are enormous benefits (physical & social) to
participating in sports there are also some dangers to your
Some sports are more detrimental to the brain thanbrain.
others (boxing, football, soccer, horse back riding, bike
riding, etc.)and a general awareness of the dangers is important. The CDC estimates that every year 300,000
sports-related concussions occur in the U.S. A concussion is a very minor form of brain trauma where the
individual loses consciousness for a short period of time. There is some concern regarding Second Impact
Syndrome (SIS), when an athlete receives a second concussion before healing from the previous one.
According to an Article in Discover magazine recent studies have shown that “football players with three or
more concussions suffer depression at three times the normal rate.” The same article also sites a study
comparing mental skills of soccer players to swimmers and runners that found soccer players are 3-4 times
more likely to have deficits in memory and planning skills. To read "Lights Out" in December's (2004) issue of
Discover click here. Studies indicate that repeated brain trauma can lead to long term problems. Muhammad
Alli suffers from pugilistic Parkinson's syndrome (caused by repeated blows to the head) after a career of
boxing.
Click here to
read about a
tragic football
accident
Wearing a helmet when bike riding
can reduce traumatic brain injury
by 85%.
Remember that brain cells DO NOT REGENERATEwhen brain cells die they are gone forever.
Click here for
more statistics
and
information on
brain trauma
The Damage Caused by
Concussion
The Neurocascade
Stage 1: An impact slams the
brain against the skull
Stage 2: To fuel the absorption
of new potassium, the neuron
consumes glucose.
Stage 3: The calcium clogged
mitochondria are starved for
oxygen causing a neuronal
energy crisis. Blood flow drops
and cells begin to die.
Graphic By Bryan Christie: Yeoman, Barry “Lights Out” Discover (online) December 2004
http://www.discover.com/images/issues/dec-04/sports-illus-65k.jpg
Remember that brain cells DO NOT REGENERATE
when brain cells die they are gone forever.
Your Life Menu
RIP
Neuron
Exercise
According to the Franklin institute online nearly 50% of people
ages 12-21 do not participate in physical activity. Less than 1/4
get at least a half hour of any type of physical activity!
Exercise has the following effects on our brains:
Animation from: http://philkaplan.com/thefitnesstruth/smallgroups.htm
• increases cerebral blood flow (the benefit?-the brains’ needs are being met
and since your brain is still developing you want it to have everything it
needs. Spoil your brain!
• increase in cognitive abilities
• a positive effect on neurotransmitters
• enhances our mood (there are conflicting theories why our mood is affected
but there is agreement that it is affected)
A study in mice showed that those mice
that exercised (using a wheel) were
better able to learn and navigate a maze.
Your Life Menu
It’s hard to imagine being old when you
are so young! But studies show that daily
exercise helps keep your brain young. It
decreases brain tissue loss.
Sleep
If you spend on average 8 hours a day sleeping, how
much of one year do you sleep away? If we “waste”
this much time sleeping there MUST be some value for
our while
bodies.
It seems as if we are not doing ANYTHING
we sleep,
however if we take a close look at our brains we will find that our
brains are very active while our bodies sleep. Examine the graphs
below, notice how active our brain is when we are asleep
compared with awake!
Scientists still are not
sure why we sleep but
there are two theories.
Why we
sleep?
Two Theories:
1. Restorative Value
This is the theory that sleep has an restorative advantage. The body uses sleep
time to recover from the mental and physical work that was done during the day.
It is thought that REM sleep is used to restore mental functions and may even
help reinforce new connections. (neuronal connections are believed to be the
basis to learning and memory) SWS sleep is thought to allow physical recovery.
Look at the graph on the previous page and compare the different types of sleep
to the recorded brain and muscle activity.
2. Adaptive Value
This is the theory that sleep has an adaptive advantage.
While an animal was not foraging for food, hunting, etc the
animal could conserve energy. Which do you think sleeps
more the hunter or the hunted?
Which animal sleeps
the most? Take a
guess then click here to
find the answer.
Image from: http://animals.timduru.org/dirlist/bear/
Lack of
Sleep
According to the an article posted on the Society of Neuroscience web
site a recent study showed the importance of sleep to procedural
memory. The researchers had subjects repeatedly type a sequence
using a key board. They found that there was no significant
improvement when the subjects were tested 12 hours later. But there
was a 20% improvement when the subjects had a full night sleep in
between the original learning and being tested again.
We all know that lack of sleep makes us cranky, makes it difficult to
concentrate on a task (listening to a lecture!), it slows down our
reaction time, and even seems to make it more difficult to solve a
problem.
Although sleep deprivation can lead to problems,
including death, the verdict is still out on whether or
not 8 hours of sleep a night is going to help you live
Your Life Menu
longer, so stay tuned.
Diet
As discussed previously your brain requires large amounts of
glucose as a fuel source. But your brain requires other
resources as well. Brains need a variety of vitamins,
minerals, amino acids, and lipids to function. Brains do more
then use energy they also form new synapses (learning),
make repairs to damaged cells, produce neurotransmitters,
and more. All of these tasks require a variety of materials for
successful brain function. Malnutrition while the brain is
growing leads to obvious problems. It’s like running out of
lumber before the house is built- no lumber the house does
not get built, no nutrition - the brain does not get built.
Remember if your body is starved so is your brain.
If your blood gets overdosed with sugar because you consumed too much glucose this
can slow your brain down. If you want to have full mental capacity not only should you
eat a “balanced diet” but stick to whole grains, veggies, fruits, and avoid pop tarts,
cookies, candy…..
Diet & Toxins
Lead
Lead is quite toxic to the brain and is most dangerous to those whose brains are still
developing. Lead blocks the majority of neurotransmitters by blocking Calcium
channels. Pencil lead is not truly made of lead, in fact you probably are not exposed
to very much lead on a daily basis. The major source of lead poisoning in young
people is old lead paint.
Mercury
What the heck is a
neurotransmitter?
Your Life Menu
Every heard of the Mad Hatter? The fictional character from “Alice in
Wonderland” who is found to be having a lovely tea party with no one in
particular. This character was based on real life hatters who often went
“mad” due to mercury poisoning, which often happened to individuals who
made felt hats. Mercury is one of the most toxic substances known to man, it
causes a number of problems which include neurological conditions.
Mercury is an industrial pollutant and does build up in certain types of fish.
There are certain limits to the amount of some types of fish people eat. But
don’t use this as an excuse there are also omega-3 Fatty acids in fish that
are GOOD for your brain.
Wright, Karen “Our Preferred Poison: A little mercury is all that
humans need to do away with themselves quietly, slowly, and
surely” DISCOVER Vol. 26 No. 03 March 2005
Illegal Drugs
Click on the drug below to find out how it affects
the brain.
Marijuana
Ecstas
y
Cocain
e
More information
on drugs and the
brain
Your Life Menu
Marijuan
a contains a molecule, elta-9-tetrahydrocannabinol (THC for short), that binds
Marijuana
to receptors found in brain neurons. The receptors are called cannabinoid receptors
are found in the parts of the brain associated with memory, concentration, perception
and movement. When THC binds to the receptors the nerve function is disrupted
“Why do we
have cannabinoid
receptors in our
brains?
We produce a chemical called anandamide
which binds to cannabinoid receptors just
like THC does. Scientists are not sure
what anandamide does in the brain.
There is no known long term affect
•sleepiness • Altered sense of space and
(although there is some suggestion
time.
•Lowered
blood
•delusions •hallucinations
that THC may affect memory) on
pressure
the brain but there are temporary
•Reduced
•disorientation
affects:
coordination
•relaxation
•Difficulty
•Impaired
Illegal Drugs Menu
concentrating
memory
Ecstasy
Ecstasy,3,4 methylenedioxymethamphetamine or "MDMA” is a
dangerous drug to party with. There are risks of dying during use
but this page will discuss long term affects on the brain.
MDMA (Ecstasy) affects serotonin in the
brain by causing the release of serotonin,
keeping serotonin from being cleaned up,
and depleting available serotonin. This
leads to an elevated mood but the loss of
serotonin will lead to a depression of the
mood. Maybe even worse than the
depression that follows ecstasy is the
damage caused to brain cells. Examine
the picture to the right, notice the
extensive damage several weeks after
ecstasy use and even after seven years
the damage is still very visible.
Remember that unlike your computer you
can’t back up your brain. Once you lose
neurons and connections you can’t
restore them.
Illegal Drugs Menu
Did you know that ecstasy was first invented and used as a medicinal drug
but the use was stopped after scientists found it caused brain damage.
Cocai
ne
Cocaine is also a VERY dangerous drug, it can
cause death during use as well as long term
damage to your brain.
Cocaine acts by blocking dopamine clean up in the brain, especially in the reward centers of the brain. It has
been found that a rewarding event causes the release of dopamine in the brain and is associated with good
feelings. Cocaine blocks the clean up of dopamine causing it to build up between neurons which leads to
constant firing of those neurons producing the good feelings. When the effects of cocaine where of the
individual often starts to feel depressed, which leads to the next use to stop the depressed feeling and return
to the euphoric feeling. Cocaine can lead to death during use because it increases blood pressure and
constricts blood vessels which can lead to a stroke (bleeding in the brain).Recent studies have found that
cocaine causes a depletion in memory and higher brain function.
“The PET scan allows one to see how the brain uses glucose;
glucose provides energy to each neuron so it can perform work. The
scans show where the cocaine interferes with the brain's use of
glucose - or its metabolic activity. The left scan is taken from a
normal, awake person. The red color shows the highest level of
glucose utilization (yellow represents less utilization and blue shows
the least). The right scan is taken from a cocaine abuser on cocaine.
It shows that the brain cannot use glucose nearly as effectively show the loss of red compared to the left scan. There are many
areas of the brain that have reduced metabolic activity. The
continued reduction in the neurons' ability to use glucose (energy)
results in disruption of many brain functions.” NIDA
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Image from: http://www.nida.nih.gov/pubs/teaching/Teaching4.html
Click here to see an animation of cocaine’s affect on the neurotransmitter dopamine.
Illegal Drugs Menu
Alcoho
Alcohol is a small molecule that easily passes the blood brain
l barrier. (Remember the blood brain barrier protects your brain
from internal invaders and chemicals) Alcohol is very easily
Obviously alcohol causes immediate
changesby
in athe
bodybody
and cause
in brain activity, like
absorbed
and changes
the brain.
slowing response time and impairing judgment, but there is evidence that there are LONG TERM
AFFECTS!!!! Research shows that alcohol consumption before the brain has finished developing
leads to less development. Remember the teen brain still has a lot of developing to go and that the
brain hasn’t finished the major changes until the age of 20.
(no wonder the drinking age is 21!) Alcohol introduced during
The images to
brain development causes problems with the brain systems
the left shows an
alcoholic man
associated with learning and memory .
The brain images to the
right show the brain
activity during a memory
task between 2 different
15 year olds. The
pink/red color indicates
brain activity. The brain
on the right belongs to a
15 yr old “drinker”
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
From Brain Briefings, 10/02 SFN,
http://web.sfn.org/content/Publications/BrainBriefings/brain_on_alcohol.html#full-size
Your Life Menu
Click here to see an animation of the effect of alcohol on nerve transmission. (Advanced)
and a nonalcoholic man.
Notice the
ventricle space
is much larger in
the alcoholic
man. Long-term
drinking results
in loss of brain
tissue as well as
causes other
damage to the
brain
Dehydratio
n
Neurotransmitters
Neurons must be able to communicate
with each other they do this by passing
on signals. There are two types of
ways neurons signal one another, both
result in a charge flowing from one
neuron to the next. Neurotransmitters
are one way neurons signal each
other. One neuron releases a
“neurotransmitter” and the other
neuron has special receptors that bind
to the transmitter thus sending
information. There are hundreds of
neurotransmitters below are just a few.
Serotonin
Dopamine
Epinephrine
Acetylcholine
Main Menu
Click here
for more
information about
neurotransmitters
This is a picture of three
neurons, each neuron is
connected to at LEAST
one other neuron. The
zoomed in portion shows
how neurotransmitters are
released from one neuron
and bind to the next.
Image from: http://www.besttreatments.co.uk/btuk/images/epilepsy_neurotransmitter.gif
Click here to see an animation
of neurotransmitters in action.
Why should I
care?
Your brain is like a computer
with one REALLY big
difference. You can back up
all the information on your
computer and if it crashes you
can restore all the information.
Well we DO NOT have a
restore button. Once the
neurons in our brains that
held a particular memory or
knew how to speak are gone
we can’t get them back. There
is no restore button. So treat
your brain well, you only get
Your Life Menu
one.
Image from: http://www.wonderquest.com/images/2004-04-09brain.jpg
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