Transcript Chapter 3: The Brain

Do Now: Is the dancer turning
clockwise or counter clockwise?
Put your
right hand
in the air
Point
palm
downward
Put your
right
finger on
your ear
Say “This
is my
favorite
ear”
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
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.
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!
Upper Brain
Mid Brain
Lower Brain
Brain Stem
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
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 does the mid brain do?
Mid Brain
Limbic
System
Emotions
Sexual
instincts
Sense of
smell
Possible connection?
What does the lower brain do?
Lower
Brain
reaction
primal
aggression
Hemispheres
•
•
•
•
Brain divided into two sides
Fissure: groove along center
Right: controls left
Left: controls right
Right Brain or Left Brain?
You have inherited 1,000,000 dollars!
Congratulations! You are moving to new
house you are having made and have to
pack your things in boxes.
1. How will you pack your priceless
glassware that Aunt Edna left you in her will
to make sure they don’t break? If any of
them break, the money has to be given to a
distant cousin. Describe in a few sentences
how you will pack the glasses?
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
Phineas Gage: Neuroscience’s Most Famous Patient
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
What is a stroke?
•
A stroke is a medical emergency. Strokes happen when blood flow to your brain stops. Within
minutes, brain cells begin to die. There are two kinds of stroke. The more common kind,
called ischemic stroke, is caused by a blood clot that blocks or plugs a blood vessel in the
brain. The other kind, called hemorrhagic stroke, is caused by a blood vessel that breaks and
bleeds into the brain. "Mini-strokes" or transient ischemic attacks (TIAs), occur when the
blood supply to the brain is briefly interrupted.
Symptoms of stroke are
• Sudden numbness or weakness of the face, arm or leg (especially on one side of the body)
• Sudden confusion, trouble speaking or understanding speech
• Sudden trouble seeing in one or both eyes
• Sudden trouble walking, dizziness, loss of balance or coordination
• Sudden severe headache with no known cause
• If you have any of these symptoms, you must get to a hospital quickly to begin treatment.
Acute stroke therapies try to stop a stroke while it is happening by quickly dissolving the
blood clot or by stopping the bleeding. Post-stroke rehabilitation helps individuals overcome
disabilities that result from stroke damage. Drug therapy with blood thinners is the most
common treatment for stroke.
NIH: National Institute of Neurological Disorders and Stroke
Do Now:
Make a happy face
Make an angry face
Make a sad face
Make a fearful face
How do you know how to do that?
Face Blindness Test
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
Do Now:
This is a G rated activity–
touch the area where your corpus callosum
(under the fissure) is
Now touch your frontal lobe.
Now your Parietal lobe
Now your Temporal lobe
Now your Occipital lobe
Now your Cerebellum
Now your Medulla Oblongata
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
Reading: Disorders of the Brain
•
•
•
•
•
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
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
Split Brain Game
Dr. Oliver Saks
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 then-experimental
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.
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
Myelinated neurons are found in the peripheral nerves
(sensory and motor neurons), while non-myelinated
neurons are found in the brain and spinal cord.
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
Sensory
Neurons
Motor
Neurons
Receptors
Interneurons
• Travel from body to brain
• Travel from brain to body.
• - sense the environment (chemicals, light,
sound, touch) and put information into
electrochemical messages transmitted by
sensory neurons
• Connect sensory and motor
neurons
lhttp://learn.genetics.utah.edu/content/addiction/drugs/mouse.html
Dopamine
Acetylcholine
• Motor functions
• Too much – Schizophrenia
• Too little – Parkinson’s, other diseases
• Attention and REM sleep inducer
• Too little – Myashenia Gravis (muscle weakness, tired,
Alzheimers Link
Endorphin
• Relieve pain, increase wellbeing
• Natural form of morphine (woo hoo!)
Serotonin
• chemical that helps maintain a "happy feeling,"
helps with sleep, anxiety, depression
GABA
(gamma-aminobutyric acid)
Reticular system
• amino acid that helps induce relaxation and sleep
builds muscle tone.
• It balances the brain by inhibiting over-excitation.
• Keeps us alert or puts us to sleep –
alcohol mimics reticular system neurons
Reuptake
• The main objective of a Reuptake Inhibitor is
to substantially decrease the rate by which
neurotransmitters are reabsorbed, leaving a
large gain in the concentration of
neurotransmitter in the synapse.
• Example: Antidepressant drugs often use ssris
(selective serotonin reuptake inhibitors) to
cause a GAIN in amount of serotonin in brain.
http://learn.genetics.utah.edu/content/addiction/reward/madneuron.html
Serotonin Overdose
Class
Drugs
5-HT1 agonists
Monoamine oxidase
inhibitors (MAOIs),[1] TCAs,[1] SSRIs,[1] SNRIs,[1]
bupropion,[6] nefazodone,[7] trazodone[7]
tramadol,[1] pethidine,[1] fentanyl,[1] pentazoci
ne,[1] buprenorphine[8]oxycodone,[9] hydrocod
one[9]
phentermine,[10] diethylpropion,[10] amphetam
ine,[3][10] sibutramine,[1]methylphenidate,[10] m
ethamphetamine,[10] cocaine[10]
triptans[1][10]
Psychedelics
Ecstasy Crystal Meth Meth] LSD[11][12]
Antidepressants
Opioids
CNS stimulants
Herbs
Others
St John's Wort,[1] Syrian rue,[1] Panax
ginseng,[1] Nutmeg[13]
tryptophan,[1] LDopa,[14] valproate,[1] buspirone,[1] lithium,[1] li
nezolid,[1][15]dextromethorphan,[1] 5hydroxytryptophan,[7] chlorpheniramine,[10] ris
peridone,[16]olanzapine,[17] ondansetron,[1] gra
nisetron,[1] metoclopramide,[1] ritonavir[1]
What did we learn?
• Myelin: fatty sheath that covers nerves similar to an electrical
wire – lesions can cause neurological symptoms
• Neurons: Motor = brain to body, Sensory = body to brain,
Interneuron=connections between nerves, Receptors=receive
neurotransmitter
• Neurotransmitters: electrical/chemical messages passed along
by neurons
• Serotonin: happy chemical
• Dopamine: movement
• Acetylcholine: sleep, attention
• Endorphins: natural morphine
DO NOW:
Reading: What are reflexes?
1. Read article
2. Answer questions for
“reading” …you will answer
the “listening” questions at
the end of class and hand in.
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.
Why do we have reflexes?
• 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
• Other examples of protective reflexes are 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
What are the reasons for reflexes?
• Evolutionary Perspective?
• Survival Instinct?
• Reflexes take place without traveling from
brain (motor neurons) to sensory neurons
How are reflexes different than reactions?
• They use inter-neurons to communicate
without direct motor neurons!
Common Reflexes
Babinski
(foot)
Rooting
(sucking)
Moro
(startle
Pupillary
(eyes – constriction
Or dilation)
Tonic
(fencing)
Galant
(leaning against
side of spine
that is stroked)
Pupillary Response
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 on Infant
Babinski Explanation
Moro Reflex
• 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
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 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.
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.
Galant Reflex
• ://www.medicalvideos.eu/video/eb2712fc2af
d7dd/Galant-Reflex--Clinical-Pediatrics
Reflexes seizures & headaches?
•
•
•
•
•
•
•
•
Migraines: blood vessel based, often preceded by signs
Cluster: mostly male, one eye – occurs at intervals
Tension: often frontal/occipital based – muscles
Seizures: Grand Mal, Petit Mal, Idiopathic, Absence – often
preceded by signs
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 adult reflexes protect us.
What have we learned?
• Cerebral Cortex – covers your brain, gray matter
• Hemispheres-each half of the brain that has different roles.
Hemisphere dominance is a theory…what do you think?
• Corpus Callosum: The Newburgh Beacon Bridge of the
Interstate 84 of your brain
• Frontal Lobe: reasoning, higher level thought processes
• Parietal Lobe: motor strip, sensory strip
• Temporal Lobe: hearing, speech
• Occipital Lobe: sight
• Medulla: autonomic functions
• Cerebellum: balance, coordination
• Pons and RAS: sleep, recognition of faces
• Prefrontal lobe: seat of the soul, personal memories
• Lower brain: primitive reactions
• Midbrain: smell, emotion (limbic system)
• The blood brain barrier protects your brain from
infection
• Myelin: fatty sheath that covers nerves similar to an
electrical wire – lesions can cause neurological
symptoms
• Right Brain/Left Brain Theory (R=holistic L= analytical
• Neurons: Motor = brain to body, Sensory = body to
brain, Interneuron=connections between nerves,
Receptors=receive neurotransmitter
• Neurotransmitters: electrical/chemical
messages passed along by neurons
• Serotonin: happy chemical
• Dopamine: movement
• Acetylcholine: sleep, attention
• Endorphins: natural morphine
• Types of reflexes: Knee Jerk, Babinski, Moro,
Fencers (Tonic)
• Primitive reflexes in adulthood often sign of
neurological disease
• Normal adult reflexes protect us.