Transcript Chapter 3: The Brain

Put your
right hand
in the air
Point
palm
downward
Put your
right
finger on
your ear
Say “This
is my
favorite
ear”
Do Now: Is the dancer turning
clockwise or counter clockwise?
Hemispheres
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Brain divided into two sides
Fissure: groove along center
Right: controls left
Left: controls right
Right Brain or Left Brain?
What is the structure of the brain?
Brain
Comprised of three major parts
•Lower Brain
•Mid Brain
•Cerebrum and Cerebral Cortex
•(upper brain)
Over 100
Billion Cells
Each part works
with others to
control what
think feel and
do.
What does the brain look like?
• Tightly compressed
macaroni
• Studying uses more
energy than jogging
• Uses 20% of your
oxygen
• Is protected in multiple
ways.
Upper Brain
Mid Brain
Lower Brain
Brain Stem
What does the lower brain do?
Lower
Brain
reaction
primal
aggression
What does the mid brain do?
Mid Brain
Limbic
System
Emotions
Sexual
instincts
Sense of
smell
Possible connection?
Why is the cerebral cortex so
important?
• Personality: makes us “human”
• “Seat of the soul”
• Example: when faced with severe brain injury
to frontal lobe– personality sometimes
changes completely
• Strokes, tumors – sometimes causes this
What your brain just did…
Analyzed instructions to lift
right hand
Triggered emotions in midbrain…”Is she nuts?” “Why
are we doing this?”
Sent to speech area to say
the words
Put words together into
sentence
Called on area that
controls hand movements
in left part of your brain
Called on area that
controls hand movements
(your finger did not end up
in your eye or nose!)
Searched memory bank for
words you needed
Corpus Callosum
Broad, thick band
running from side to
side and consisting
of millions and
millions of nerve
fibers.
Connections
between left and
right sides of brain.
Highway of
information – it is the
Newburgh-Beacon
Bridge of the I-84 of
your brain!
Where does the brain sit?
Central Station of
Human Nervous System
CNS (Central Nervous
System)
Floats in cerebrospinal
fluid
Enclosed in the cranium
Most common damage:
stroke, blunt head
trauma
How is the brain protected?
• Protected by the thick
bones of the skull
• Cerebral Cortex covering
• Suspended in
cerebrospinal fluid
• Isolated from the
bloodstream by the
blood-brain barrier a
semi-permeable
membrane that protects
the brain.
• The delicate nature of the
human brain makes it
susceptible to many types of
damage and disease.
• Infection of the brain is rare
because of the barriers that
protect it, but is very serious
when it occurs.
• Multiple Sclerosis-mylen,
insulation for nerves, is
impaired.
• Parkinson’s Disease,
Huntington’s Chorea = CNS
diseases
What is the Upper Brain?
• Cerebral Cortex: outermost layer of
brain covers the cerebrum – gray
matter.
• Higher level thought
• 100 Billion nerve cells
• It is the most highly developed part
of the human brain and is
responsible for thinking, perceiving,
producing and understanding
language.
• It is also the most recent structure
in the history of brain evolution
Summary
There are three parts to the brain on a horizontal level
• Upper Brain: higher level thinking
• Mid Brain: (Limbic System)vision, hearing, motor
control, sleep/wake, arousal (alertness), and
temperature regulation
• Lower Brain: primitive functions, aggression, fight or
flight
• Brain Stem: autonomic functions
• Two hemispheres – right hemisphere controls left, left
hemisphere controls right
• Brain Dominance Theory: Right brain dominant – art,
language, creative. Left brain – logical, math, organized
Cerebral cortex: covers brain (gray matter)
Fissure: groove along middle of brain
Parietal Lobe: sensory strip
Motor Strip: along frontal lobe - movement
Temporal Lobe: speech, hearing
Prefrontal Lobe:
:personal
memories
Occipital Lobe:
interprets visual
information
Frontal Lobe::reasoning, personality,
Cerebellum: balance, Reticular Activating System:
Thought, complex thoughts
alertness
coordination
Chronic traumatic encephalopathy
• The only known diagnosis for CTE occurs by studying
the brain tissue after death. CTE has been most
commonly found in professional athletes participating
in American football, who have experienced repetitive
brain trauma
• show symptoms of dementia, such as memory loss,
aggression, confusion and depression, which generally
appear years or many decades after the trauma.
• a progressive degenerative disease, which can only be
definitively diagnosed postmortem in individuals with a
history of multiple concussions and other forms of
head injury.
As of December 2012, thirty-three former National
Football American football
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•Lew Carpenter[64]
•Lou Creekmur[64][65]
•Dave Duerson[66]
•Shane Dronett[67]
•Cookie Gilchrist[68]
•John Grimsley[69]
•Chris Henry[70]
•Terry Long[71]
•John Mackey[30]
•Ollie Matson[30]
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•Tom McHale[72]
•Joe Perry[73]
•Junior Seau[74]
•Justin Strzelczyk[71]
•Andre Waters[71]
•Mike Webster[71]
(NFL) players have been
diagnosed post-mortem with
Do Now: Reading –
Phineas Gage: Neuroscience’s Most Famous Patient
Reticular Activating System
• Keeps us alert or puts us to sleep – alcohol
mimics reticular system neurons
The reason that
most drunk driving
accidents are due
to drivers falling
asleep at the wheel
Do Now: Draw a Clock
Mini-cog
During the mini-cog, a
person is asked to complete
two tasks:
1. Remember and a few
minutes later repeat the
names of three common
objects
2. Draw a face of a clock
showing all 12 numbers in
the right places and a time
specified by the examiner
3. The results of this brief test
can help a physician
determine if further
evaluation is needed.
Mini-mental state exam (MMSE)
During the MMSE, a health professional asks a patient a series of questions designed
to test a range of everyday mental skills.
1.
2.
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4.
5.
6.
7.
8.
Examples of questions include:
Remember and repeat a few minutes later the names of three common
objects (for instance, horse, flower, penny)
State the year, season, day of the week and date
Count backward from 100 by 7s or spell "world" backwards
Name two familiar objects in the office as the examiner points to them
Identify the location of the examiner's office (state, city, street address,
floor)
Repeat a common phrase or saying after the examiner
Copy a picture of two interlocking shapes
Follow a three-part instruction, such as: take a piece of paper in your right
hand, fold it in half, and place it on the floor
Disorders of the Brain
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Attention Deficit Disorder
TBI: Traumatic Brain Injury
Alzheimer’s Disease
Dementia with Lewey Bodies:
Although, where Alzheimer’s disease usually begins quite
gradually, DLB often has a rapid or acute onset, with especially
rapid decline in the first few months.
• While the specific symptoms in a person with DLB will vary,
core features of DLB are: 1) fluctuating cognition with great
variations in attention and alertness from day to day and hour
to hour 2) recurrent visual hallucinations. 3.)REM Behavior
Disorder
• List as many fruits as you can!
• Get ready, get set GO!
• Subjects were asked to list as many types
of fruit they could think of in a second
timed test.
• In 2005, a study was reported in
"Neuropsychologia" in which researchers
tested 96 people diagnosed with
Alzheimer's and compared the results to
40 healthy people.
• Researchers found that healthy test subjects
were able to list 20 to 25 words in each test,
but patients with Alzheimer's could remember
only 10 to 15 words.
• The Alzheimer's patients were unable to
remember words learned later in life but
could remember words learned in early
childhood. This pattern was so consistent that
researchers were able to determine which
subjects had Alzheimer's based on this word
loss.
What are some other parts of their
brain and their purpose?
Brain stem: internal physical state of body
Medulla Oblongata: breathing, heartbeat
Pons: regulates brain during sleep
Thalamus: relay station between senses and
cerebral cortex
Cerebellum: balance and movement
Limbic system: emotions, memory
Hippocampus: long term memory
Amygdala: aggression, emotion, motives, (very
active during adolescence)
Hypothalamus: eating, drinking, body temperature
Split Brain Game
1. Who was Phineas Gage and what did we learn
from him?
2. What part of your brain controls long term
No fair –darn
memories? Hint:
Hippos!!!
3. What rare and controversial procedure is
sometimes done to patients with severe
seizure disorders?
Pupillary Response
Central Nervous
System
Brain
Spinal Cord
Peripheral
Nervous System
Sensory
neurons
Motor Neurons
What are Neurons?
Neurons
• Cell body
• DNA,
Mitochondria,
Ribosomes
(protein)
Axons
• Long cable-like
• Carries nerve
impulse on
length of cell
Myelin
• Thin covering
over nerve
• Like insulated
electrical wire
Dendrites
• Branches
connect
to/communicate
with other cells
• Located at either
end of cell
What are Neurons?
• A neuron is a nerve cell
• Neurons transmit information
throughout the body in both
chemical and electrical forms to send
information to other cells.
• The axon and dendrites are
specialized structures designed to
transmit and receive information.
• The connections between cells are
known as a synapses.
• Neurons release chemicals known as
neurotransmitters into these
synapses to communicate with other
neurons.
The Role of Neurons in your Brain
I travel from
body to
brain
I travel
from brain
to body
Motor
Neuron
Sensory
Neuron
Neurotransmitters
What he
said….
We put information
into electrochemical
messages
transmitted by
sensory neurons
Inter
Neuron
I connect sensory
and motor
neurons
Quick Review:
Synapses, neurotransmitters & neurons…oh my!
Neuron
Synapse
Neurotransmitters
• Gather and transmit
electric and chemical
signals
• Point where 2 or more
neurons connect, (pass
info)
• Signals travel up to several
feet
• Chemicals in the endings
of nerve cells that send
information across
synapse
http://learn.genetics.utah.edu/content/addiction/reward/madneuron.html
What are Some Neurotransmitters made up of?
Dopamine
Motor Functions
Too much – Schizophrenia (theory)
Too little – Parkinson's and other
movement diseases
Acetylcholine
Attention and R.E.M. Sleep Inducer
Too little: muscle weakness
Endorphin
Relieve pain, Natural form of morphine
(woo hoo!)
Serotonin
chemical that helps maintain a "happy
feeling," helps with sleep, anxiety,
depression
GABA
gamma-aminobutyric acid
amino acid that helps induce relaxation
and sleep builds muscle tone.
It balances the brain by inhibiting overexcitation
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Sensory Neurons:
Travel from body to brain
Motor Neurons:
What did we learn?
Travel from brain to body
Interneurons:
Connect sensory and motor neurons
Neurotransmitters:
Chemicals in the endings of nerve cells that send information across
synapse
Central Nervous System:
Brain and Spinal Cord
Peripheral Nervous System:
Stem off from spinal cord
What are reflexes?
•A reflex is an involuntary or automatic,
action that your body does in response to
something - without you even having to think
about it.
• There are many types of reflexes and every healthy
person has them. In fact, we're born with most of
them…and most of them fade by age 6 months.
•Some infant reflexes that show up in adulthood can
be signs of neurological disease.
• Reflexes protect your body from things
that can harm it.
• For example, if you put your hand on a
hot stove, a reflex causes you to
immediately remove your hand before a
"Hey, this is hot!" message even gets to
your brain
• Blinking when something flies toward
your eyes or raising your arm if a ball is
thrown your way. Even coughing and
sneezing are reflexes. They clear the
airways of irritating things
Common Reflexes
Babinski
(foot)
Rooting
(sucking)
Moro
(startle)
Pupillary
(eyes – constriction
Or dilation)
Tonic
(fencing)
Galant
(leaning against
side of spine
that is stroked)
Babinski on Infant
Babinski Reflex
• Babinski's reflex occurs when the big toe
moves toward the top of the foot and the
other toes fan out after the sole of the foot
has been firmly stroked.
• This reflex, or sign, is normal in younger
children, but abnormal after the age of 2
• The presence of a Babinski's reflex after age 2
is a sign of damage to the nerve paths
connecting the spinal cord and the brain
Babinski Explanation
Moro
Moro Reflex
• Arms will rapidly fan out as if startled.
• It is normally present in all infants/newborns
up to 4 or 5 months of age
• Absence indicates a profound disorder of the
motor system.
• Persistence of the Moro response beyond 4 or
5 months of age is noted only in infants with
severe neurological defects
• It is believed to be the only unlearned fear in
human newborns
Moro Reflex in baby kitten too
Tonic (Fencers) Reflex
• known as the “fencing reflex" because of the
characteristic position of the infant's arms
and head, which resembles that of a trained
fencer.
• Beyond the first months of life may indicate
that the child has developmental delays, at
which point the reflex is atypical or abnormal.
For example, in children with cerebral palsy
the reflexes may persist and even be more
pronounced.
Tonic
Knee Jerk (Patellar) Reflex
Causes of Abnormal Knee Jerk Response
• Hyperactive (knee jerks too much): ALS, brain
tumor, stroke, liver disease, hypocalcemia (low
calcium), hypomagnesemia (low magnesium),
hypothermia, multiple sclerosis, preeclampsia,
spinal cord lesion and tetanus.
• Hypoactive (knee doesn't jerk enough):
botulism, nerve inflammation, peripheral
neuropathy, polio, untreated syphillis,
diabetes, alcoholism, arthritis, etc.
What have we learned about
reflexes?
• Types of reflexes: Knee Jerk, Babinski, Moro, Fencers (Tonic)
• Primitive reflexes in adulthood often sign of neurological
disease
• Absence of reflexes in infancy – neurologicial problem
• Normal reflexes protect us.
• Reflexes use interneurons – not sensory or motor neurons.
Reading
Knee Jerk or (DTR) reflex
• The reflex that the doctor checks by tapping
your knee is called the patellar, or knee-jerk,
reflex. It is also known as a deep tendon reflex
(DTR) This tap stretches the tendon and
the muscle in the thigh that connects to it.
• A message then gets sent to the spinal cord
that the muscle has been stretched. The spinal
cord very quickly sends a message back to the
muscle telling it to contract. The contraction
of the muscle causes your lower leg to kick
out.
Do Now: Awakenings – final day
• In reality, Dr. Sacks was conducting a double blind study
with 50% of the group on the L-Dopa and the rest on a
placebo. When Dr. Sacks saw the respons, he
immediately put the entire group on the drug. The
family members had to sign approvals releasing the
hospital from responsibility. Do you think this was
ethical? Why/Why not?
• Even though Dr. “Sayer” was the doctor and Leonard
was the patient – do you think he learned anything
from Leonard. Do you think it would’ve been better for
the patients to remain in their frozen states rather than
giving them back life for only a summer?
Headaches
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Vascular Headaches: Migraines
Muscle Headaches: Cluster, Tension
Worst Headache of your life! – aneurism
Seizures: Grand Mal, Petit Mal, Absence
• Types of reflexes: Knee Jerk, Babinski, Moro,
Fencers (Tonic)
• Primitive reflexes in adulthood often sign of
neurological disease
• Normal adult reflexes protect us.
Dr. Oliver Sacks
In 1966 Dr. Sacks began working as a consulting neurologist
for Beth Abraham Hospital in the Bronx, a chronic care
hospital where he encountered an extraordinary group of
patients, many of whom had spent decades in strange,
frozen states, like human statues, unable to initiate
movement. He recognized these patients as survivors of
the great pandemic of sleepy sickness that had swept the
world from 1916 to 1927, and treated them with a thenexperimental drug, L-dopa, which enabled them to come
back to life.
They became the subjects of his book Awakenings, which
later inspired a play by Harold Pinter ("A Kind of Alaska")
and the Oscar-nominated feature film ("Awakenings") with
Robert De Niro and Robin Williams. Dr. Sacks is a NYT
bestselling author and award winning Neurologist. You can
reach him at
This film is based on a true story
Do you remember?
• Why do we have reflexes?
• Describe two reflexes you have now
• Describe one reflex you don’t have anymore
and why