10/8 ap psych class announcements : test or vocab quiz make-up: shaniya, madeline, brooklyn, aim: to...
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10/8 AP Psych Class Announcements:Test or vocab quiz make-up:
Shaniya, Madeline, Brooklyn,
Aim: to discuss the functions of the nervous system categories, label the parts of the brain
Do NOW: “The Science of Love”Turn in article
HW: Bring Playdough!!
Help class Wed after school
10/11,14 AP Psych Class Announcements:Test or vocab quiz make-up: Aim: explain functions of
various parts of the brain
Do NOW: noneTurn in article answers
HW: practice questionsStudy for testTurn in ch 2 notecards
The Biology of Mind
Chapter 2
Ways we Study the Brain
• Accidents• Lesions• EEG• CAT Scan• PET Scan• MRI• Functional MRI
Accidents
Phineas Gage Story• Personality changed
after the accident.What does this tell us?• Answer: Different
parts of the brain control different aspects of who we are!!!!!
Phrenology
• Early attempt to study the brain
• Franz Gall• He tried to “map” out
the brain with corresponding personality traits.
• They were identified by feel the bumps on your head
Lesions
• Purposeful removal or destruction of some part of the brain.
Electroencephalogram
• EEG machine• Detects brain waves
through their electrical output.
• Used mainly in sleep research.
Computerized Axial Tomography
• CAT Scan• 3D X-Ray of the
brain.• Good for tumor
locating, but tells us nothing about function.
CT example
Magnetic Resonance Imaging
• MRI• More detailed picture
of brain using magnetic field to knock electrons off axis.
• Takes many still pictures (slices)and turns images into a movie like production.
• Does not study function!
MRI example
• Notice the tumor…
Positron Emission Tomographyor PET Scan• Measures how much of a chemical the brain is using (usually
glucose consumption). Patient drinks a radioactive sugar which show up when certain parts of the brain are being used.
• Good for studying function!!
PET scan• Depression
Functional MRI• Combination of PET and MRI• fMRI is good for function, hence the f.
The Biology of MindI. Neural Communication
Neurons
How Neurons Communicate
How Neurotransmitters Influence Us
II. The Nervous System
The Peripheral Nervous System
The Central Nervous System
III.The Brain
Neural Communication
Note the similarities in the above brain regions, which are all engaged in information processing.
Neurobiologists and other investigators understand that humans and animals operate
similarly when processing information.
Neural and Hormonal Systems
Will Explain Why We FEEL……
Pain
Strong
Sick
Nervous
NeuroanatomySynapseSynapse
Neurotransmitters (chemicals held in terminal buttons that travel through synaptic gap)
Parts of a Neuron
Cell Body: Life support center of the neuron.
Dendrites: Branching extensions at the cell body. Receive messages from other neurons.
Axon: Long single extension of a neuron, covered with myelin [MY-uh-lin] sheath to insulate and speed up messages through neurons.
Terminal Branches of axon: Branched endings of an axon that transmit messages to other neurons.
Parts of a neuron:
• http://learn.genetics.utah.edu/content/addiction/reward/madneuron.html
1. Resting potential……
• Draw the axon membrane at resting potential
Na+ (sodium) is outside the membrane
K+ (potassium) is inside the membrane too, but a mainly negative charge exists INSIDE the membrane.
Polarized
• At resting potential, we say the cell is polarized, that is, the + and – charge are at opposite position (one is in the membrane, one is outside).
2. Threshold Threshold: Each neuron receives excitatory and inhibitory signals from many neurons. When the excitatory signals minus the inhibitory signals exceed a
minimum intensity (threshold) the neuron fires an action potential.
Gas vs. brake pedals of a car!!!!
3. Action Potential4. Depolarization
Action Potential-if threshold is reached, process of firing begins. Gates open and Na+ ions begin moving in and out of the axon Depolarized- during action potential when the ions are moving in and out.
Action PotentialA neural impulse. A
brief electrical charge that travels down an
axon and is generated by the movement of positively charged atoms in and out of
channels in the axon’s membrane.
5. Refractory
•Refractory period- for a short time (before the ions can return to original position) the neuron can’t fire again immediately
•Ex: when you flush a toilet, you can’t flush again immediately
6. Repolarize
• The ions must go back to original position to be ready to fire again.
• EX: This is like when the toilet bowl is filling up with water
The All-or None Response
• The idea that either the neuron fires or it does not- no part way firing.
• Again, you can’t “kinda” flush a toilet!!
Review• Put the following events in their proper order
transmission to your “Study Buddy” :• Refractory
• Depolarized• Resting potential• Action potential
• repolarize• Threshold
• Excitatory vs. inhibitory signals• polarized
How does the brain perceive intensity, like pain?
By the number of times the neuron fires!!!!!!
How does the process create an electrical charge?The transfer of ions crossing the axon’s membrane causes an electrical charge.
Review:How does a Neuron fire?
• 1. Resting Potential: the neuron before it fires- is polarized
• 2. Threshold reached- more excitatory than inhibitory signals
• 3. action potential begins• 4. axon is depolarized – ions
move in and out• 5. refractory/repolarization-
reloading of ions- filling up the toliet bowl
So….how do nerve cells communicate?
• Do nerve cell touch each other and send the electrical charge to each other?
• How would they know what “message” to send?
• No!! They do not touch!
• They are separated by a tiny gap.
• So…how does each cell communicate across a gap?
At the Synapse
Synapse [SIN-aps] a junction between the axon tip of the sending neuron and the
dendrite or cell body of the receiving neuron. This tiny gap is called the synaptic gap or
cleft.
NeurotransmittersNeurotransmitters
(chemicals) released from the sending neuron travel across the synapse
and bind to receptor sites on the receiving
neuron, thereby influencing it to generate
an action potential.
They fill in receptor sites like keys to a key hole.
Lock & Key Mechanism
Neurotransmitters bind to the receptors of the receiving neuron in a key-lock mechanism.
Reuptake
Neurotransmitters in the synapse are
reabsorbed into the sending neurons
through the process of reuptake. This
process applies the brakes on
neurotransmitter action.
Reuptake demonstration
• http://www.thirteen.org/closetohome/animation/coca-anim-main.html
• Neurotransmitters to know:
• 1.Dopamine• 2. ACH• 3. serotonin• 4. endorphins• 5. glutamate• 6. GABA
What is an SSRI?
• Selective Serotonin Reuptake Inhibitor
• Prozac, Zoloft, Celexa etc…..
• These are anti-depressants that block the reuptake of serotonin, therefore, making sure the synapse is filled with serotonin
How is a neural transmission both an electrical and a chemical response?
• Electrical- action potential create electricity
• Chemical- at the synapse
1. Acetylcholine (ACH)
• Deals with motor movement and memory.
• Lack of ACh has been linked to Alzheimer’s disease.
2. Serotonin
It’s pathways are involved with mood sleep and hunger.
Too little: depression
Too much: mania
From Mapping the Mind, Rita Carter, © 1989 University of California Press
3. Dopamine• Its function is:
motor movement, pleasure and
alertness.
Too little: dopamine is associated with Parkinson’s disease.
Too much : is associated with
schizophrenia.
Norepinephine
• Chemically the same as adrenaline• Controls alertness and arousal
• Too little: depression
4. Endorphins• Function deals with pain
control.
We become addicted to endorphin causing feelings.
5. GABA
• an inhibitory neurotransmitter
• Too much: you become sedate, drowsy
• Too little: anxiety
6. Glutamate• An excitatory neurotransmitter
Too much: MSG excites neurons, starting migraines
Too little: memory , concentration problems
Drugs can be…..
• Agonists- mimc and make neuron fire
• Antagonists- stop neural firing
• Reuptake Inhibitors- block reuptake
What are agonists and antagonists?
• Agonists mimic neurotransmitters.• Ex: Morphine mimics endorphin.
• Antagonists block neurotransmitters:• Ex: curare blocks ACh (paralyzes you)
Botox blocks ACh
Agonists
Antagonists
Types of Neurons
• Sensory (afferent) Neurons- from senses to spinal cord
• Interneurons from spinal cord to brain
• Motor (efferent) Neurons-from brain back to muscles, glands
Neural Chain
What about a reflex?
• Sensory neuron motor neuron
• Hit knee to spinal cord motor neuron
There is no “inter neuron” involved!!!!!!
Nervous System
CentralNervousSystem(CNS)
PeripheralNervousSystem(PNS)
The Nervous System
Autonomic Nervous System (ANS)
Sympathetic NS “Arouses”
(fight-or-flight)
Parasympathetic NS “Calms”
(rest and digest)
Central Nervous System
The Brain and Neural Networks
Complex Neural Network
Interconnected neurons form networks in the brain. Theses networks are complex and modify with growth and experience.
The Endocrine System
The Endocrine System is the body’s “slow”
chemical communication
system. Communication is
carried out by hormones
synthesized by a set of glands.
Hormones
Hormones are chemicals synthesized by the endocrine glands that are secreted in the
bloodstream. Hormones affect the brain and many other tissues of the body.
For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar, and feelings of excitement during
emergency situations.
Pituitary Gland
Is called the “master gland.” The anterior pituitary lobe releases hormones that
regulate other glands. The posterior lobe regulates water and salt balance.
Adrenal GlandsAdrenal glands secretes hormones
(epinephrine and norepinephrine :a.k.a adrenaline) during stressful and emotional
situationsbtw: norepinephrine is both a
neurotransmitter and a hormone
•Nervous System Practice Questions
Answers:
• 1. B 8. B• 2. A 9. A• 3. C 10. B• 4. C 11. E• 5. B 12. A• 6. A 13. B• 7. B 14. D
The Brain: Older Brain Structures
The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival
functions.
Brainstem
The Medulla [muh-DUL-uh] is the base
of the brainstem that controls heartbeat
and breathing.
Pons• Located just
above the medulla.
• Involved in facial expressions. (Pons = yawns)
Reticular Formation
• controls arousal and ability to focus our attention.
• Reticular = net (like pantyhose); opens
during day• Damage to it results in
comaIf Destroyed
Thalamus• Switchboard “relay
station” of the brain.• Receives sensory
signals from the spinal cord and sends them to other parts of the brain.
• Receives info from every sense except smell.
Cerebellum
• Bottom rear of the brain.
• Means “little brain”
• Coordinates fine muscle movements and balance.
The Limbic System
The Limbic System: our emotional center!!!!
• The Limbic System is a doughnut-shaped system of neural associated with emotions such as fear, aggression and drives for food and sex.
Hypothalamus• Maybe most
important structure in the brain!!!!
Controls• Sleep• Eating, drinking• Pleasure, emotions• Body temperatureThe most powerful structure in the brain.
Rat with an Implanted Electrode in pleasure center of Hypothalamus
Reward pathways
• http://bcs.worthpublishers.com/introvtk/player/pages/inst_Browes_page.aspx?From=Search&Tab=bPage&SearchTerm=brain&SearchFrom=Gen
Hippocampus• Involved in the
processing and storage of memories.
• Its proximity to your emotional centers explains why memories and emotions are so linked!
Amy G. Dala
• Is a very emotional girl “Drama Queen”
Amygdala
• Brain part involved in telling your body to produce norepinephrine (adrenaline)
• More involved in volatile emotions like anger and jealousy.
What would happen to you if your limbic system were disconnected from you frontal lobe?
• The Phineas Gage
Story
Cerebral Cortex
• The intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is the body’s ultimate control and information processing center.
• It’s what marks us different from animals!
Features of he Cerebral Cortex
• Made up of densely packed neurons we call “gray matter”
• Glial Cells: support brain cells.
• Wrinkles are called fissures.
• It’s divided into 2 hemispheres and 4 lobes!
The Cerebral Cortex is made up of four Lobes.
Frontal Lobe
• Controls abstract thought, personality and emotional control and planning.
• Developed frontal lobe = maturity!!!!!!!!!!!!!!!!
• Lobotomies damage this.
What is the motor cortex?• Part of the brain in the frontal lobe that tells my body how
to move (like typing this).
http://www.pbs.org/wgbh/aso/tryit/brain/#
What is the sensory cortex?
It’s the part that senses our 5 senses. It’sIn the parietal lobe.
What are Motor and Sensory Cortexes?
The wires are switched! Right controls left!The motor cortex is in which lobe?
Parietal Lobes• Contain Sensory
Cortex: receives incoming touch sensations from rest of the body.
• Most of the Parietal Lobes are made up of Association Areas.
Occipital Lobes
• Think “optical”.• Contains Visual
Cortex: interprets messages from our eyes into images we can understand.
Temporal Lobes
• Located in the thumb-shaped area
• Process sound sensed by our ears.
• Interpreted in Auditory Cortex.
Specialization and Integration in Language
LanguageAphasia is an impairment of language, usually caused by left hemisphere damage
either to Broca’s area (impaired speaking) or to Wernicke’s area (impaired understanding).
Language areas
1. Broca’s – speech “He broca his tongue and can’t speak!”
2. Wenicke’s – allows you to understand what others are saying
“I don’t understand why Nick and Jessica broke up”
3. Angular Gyrus – allows to read in your head
Corpus Callosum
• The “bridge” between the two hemispheres
The brain is sculpted by our genes but also by our experiences.
Plasticity refers to the brain’s ability to modify itself after some types of injury or
illness.
“Practice makes perfect”- the more you practice a skill, the more the brain changes.
Plasticity
The hemispheres of the brain
Left Hemisphere: logic, sequential and language tasks .
Right Hemisphere: spatial, creative tasks and name recognition.
Video: Split brain patient
• https://www.youtube.com/watch?v=RFgtGIL7vEY
• 10 minutes
Review: Brain Parts
List all the parts of the brain you would be
using for the following tasks:
Driving a car
Arguing with someone by text message
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