Brain, Body, & Brain, Body, & BehaviorBehavior

NERVOUS SYTEM NEURONS

BRAINNEUROTRANSMITTERS

ENDOCRINE SYSTEMIMMUNE SYSTEM

DID YOU KNOW THAT… DID YOU KNOW THAT… Some cells in your nervous system are more than 3 feet long?

Our bodies produce natural painkillers similar to some narcotic drugs?

95% of fetuses suck their right thumbs? Raising the body temp. of a finger may relieve the pain of a migraine headache?

Men’s & women’s bodies produce both male & female sex hormones?

IntroIntroALL behaviors & mental processes are influenced by or based on biology◦study the brain in detail

Behaviors & mental processes can’t be fully understood through bio alone!!!• Oversimplify =

not credible

AVOID THE “BIOLOGY IS DESTINY” PITFALL◦WE ARE THE PRODUCT OF AN INTRICATE INTERACTION OF BIO. & ENVIRONMENTAL FACTORS

NERVOUS SYSTEMNERVOUS SYSTEM

NERVOUS SYSTEMNERVOUS SYSTEMBrain, spinal cord, nervesprocesses info. from:

◦1) inside the body◦2) external environ.

NEURONS◦cells in the nervous system (brain cells & nerve cells

◦Specialized to respond to signals & send signals of their own

3 Main Functions3 Main FunctionsINPUT: receiving info. about what is going on inside & outside (senses) your body

PROCESSING: combining info. with past experiences (if any) & decide how to react/behave

OUTPUT: brain activates muscles to act on what to do about it (the info. received)

INPUT INPUT PROCESSING PROCESSING OUTPUT OUTPUT

Q: How can the nervous system do this? ◦A: Neurons! must COMMUNICATE NeurotransmittersElectrical signals

100 billion neurons that are separate but still able to alternate signals from one circuit to another

DIVISIONSDIVISIONS• 1) CENTRAL

NERVOUS SYSTEM • brain & spinal cord• Info is sent here from

PNS to be shot up the spinal cord to the brain to be processed .

– The ‘CEO’ of the nervous system

2) PERIPHERAL NERVOUS SYTEM ◦all nerves not in the brain & spinal cord.

◦PNS collects info. to be sent to the CNS.

2 subdivisions of PNS◦Somatic: sensory nerves & motor nerves

◦Autonomic: Automatic processes

Signals must make a ‘full circuit’ in order for you to process sensory & motor info

Peripheral nerves spinal cord brain spinal cord original peripheral nerves

NEURONSNEURONSNerve cellmore advanced than your typical cell◦ involved w/ receiving, moving, & processing info.

PARTSCell Body Receptor Axon

terminals Dendrites AxonSynapse VesiclesNeurotransmitters Myelin

PARTS OF THE NEURONPARTS OF THE NEURONCell Body: contains a nucleus that caries DNA info; determines how the cell functions

Dendrites: fibers of the neuron that receive signals/info from the axons of other neurons. Dendrites Detect signals from other neurons◦Carries the signals to the cell body to be interpreted

Axon: fibers that carry signals away from the cell body to where communication occurs with other neurons. Axons carry signals Away from the cell body to axon terminals

Axon Terminal: areas @ the end of an axon where neurotransmitters are released

Synapse: gap between neurons. Where neurotransmitters “jump” from one neuron to another.

Neurotransmitters: chemicals that transfer information from one neuron to another by “jumping” across the synapse. ◦can only “fit” into its own receptors

Vesicles: Little “bubbles” where neurotransmitters are stored at the end of an axon.

Receptor: where neurotransmitters fit into the receiving dendrite of the next neuron.

Myelin sheath: insulating protein layer that surrounds the axon in order to speed up communication & contain the electric pulses.

HOW DO NEURONS HOW DO NEURONS COMMUNICATE?COMMUNICATE?

Dendrites accept neurotransmitters from other neurons and transfer that info to the cell body.

That info is shot down the axon in the form of electrical signals.

When these electrical signals reach the end of the axon, it releases the neurotransmitters (chemical signals) from the vesicles.

The neurotransmitters “jump” across the gap between neurons, known as the synapse.

The neurotransmitters then bind to their proper receptors on the dendrites of the receiving neuron (like a puzzle). ◦Dendrites get excited when they detect neurotransmitters in their receptors & send info. to the cell body.

THE WHOLE PROCESS STARTS OVER

‘‘CLOSE UP’ VIEW OF NEURAL COMMUNICATION CLOSE UP’ VIEW OF NEURAL COMMUNICATION BTW 2 NEURONSBTW 2 NEURONS

Rules of Neural CommunicationRules of Neural Communication1) NEURONS EITHER FIRE OR DON’T FIRE. IT’S “ALL OR NOTHING”◦rate of firing can differ

2) Can only communicate w/ other neurons that are close to them.

3) MUST MAKE FULL CIRCUIT! ◦Nerves spinal cord brain spinal cord same nerves

When you are ‘killing brain cells’, you are killing NEURONS & CONNECTIONS!

LOU GEHRIG’S DISEASELOU GEHRIG’S DISEASEWasting away of motor

neurons in brain & spinal cord

Progressive, disabling, & fatal

Symptomsinability to control

mvmt, loss of muscle control

Neurons waste away = muscles waste away too

AUTISMAUTISMBrain dev. disorder – abnormalities & deficits in: ◦Social interaction◦Restricted interests & repetitive behavior

Deficit in mirror neurons (?)Probs empathizing w/ & imitate others

MULTIPLE SCLEROSIS (MS) MULTIPLE SCLEROSIS (MS) Immune system slowly destroys Myelin sheaths Slows communication

Progressive & fatal350,000 Americansonset = 20 – 40 yrs old

Symptoms: loss of the ability to speak, walk, write, eventually breath & heartbeat

THE BRAINTHE BRAIN

THAT MAGNIFICENT BRAIN OF THAT MAGNIFICENT BRAIN OF YOURS! YOURS!

Sits in a fluidThere are psych. changes when the brain experiences trauma or chemical changes .

DIVIDED INTO 3 MAIN PARTS◦a.k.a ‘the 3 brains’◦each contains specialized structures

HINDBRAINHINDBRAINmost primitive part; vitalsIncoming signals reach here 1st

Medulla: vital bodily functions (breathing, swallowing, circulation)

Reticular Formation: “net”work of fibers (neurons); arousal & attn

Cerebellum: basic motor activities; coordination (sequencing/ timing); posture, balance, normal speech patterns

MIDBRAINMIDBRAINIntegrates mvmt w. sensory info, & relays it up to the rest of the brain ◦Ex. Loud noise turn in head in direction of the sound

FOREBRAINFOREBRAINmost complex aspectsThalamus: relay station for sending messages to & from parts of the brain

Hypothalamus: ‘pleasure center’; regulates hunger, thirst & sex drive; controls rage

Hippocampus: regulate emotion & form LT memories

Cerebrum: high level thinking process◦Emotions, memories, personality, logic, decision making, planning, etc.

◦Largest part◦Div. into 2 hemispheres (halves) & 8 lobes

Cerebrum Cerebrum Whole Whole brainbrain

Corpus Callosum –band of fibers in the mid of the brain – connects the 2 hem.

LOBES of CEREBRUMLOBES of CEREBRUMCerebrum / 4 lobes

◦Each is specialized◦all work together in order to collect, analyze, store, & respond to information

All 4 lobes are found in both hemispheres (mirror image)

Deep groves in the brain mark where the difft lobes are

PARIETAL◦body & skin sensations◦Touch, pressure, temp., pain, movement

TEMPORAL◦sound sensations◦auditory info; involved in hearing, memory, speaking

OCCIPITAL◦visual info (vision center)◦Optic nerves directly connected to here

FRONTAL◦Arranges incoming info into meaningful perceptionsMost advanced cog. processes

◦Language, organizing, planning, problem solving, decision making, personality, learning, dreaming, emotions, memories, creativity, & thinking

◦Control of the body

POOR PHINEAS! POOR PHINEAS! major changes in behavior

Able to see the connection btw damaged parts of the brain & behavior

Why did he survive?

Before◦friendly; good judgment, cooperative, enjoyable

After◦short-temper; swore; urinated & undressed in public; said inappropriate things; aggressive; violent;

Damage to what lobe? FRONTAL!◦Severe changes in personality, judgment, & rational thought

◦prevented censoring of thoughts, ideas, & social functioning

Right & Left Cerebral Right & Left Cerebral HemispheresHemispheres

LATERALIZATION OF THE CEREBRUMLATERALIZATION OF THE CEREBRUMLateralized

◦2 hemispheres are specialized for processing certain kinds of info.

Each hem. controls the opposite ½ of the body◦Right 1/2 controls left side of body◦Left 1/2 controls right side of body

We constantly use both◦compliment each other◦Work in harmony to jointly control human functions

2 hems. connected by the corpus callosum. (communication)◦processed in one half, then sent to the other to be processed… then both ‘analysis’ are integrated to produce one flow of thought & behavior

LEFT HEMISPHERE◦LANGUAGE (verbal): speaking, understanding language, reading, writing

◦Sequences & order; time◦Math: algebra, calculus, physics◦Detail-oriented◦‘Safe & logical’◦Process info. logical & sequential

FUNCTIONS/ CHARACTERISTICS

Right Hemisphere◦Nonverbal: body language; emotions; visual symbols & images

◦Spatial: patterns; objects in ‘space’; art & music

◦Math: geometry ◦‘Big picture’ oriented◦‘Impulsive’ ◦Process info. intuitively, simultaneously, & randomly

HEMISPHERES & HEMISPHERES & PREFERENCEPREFERENCE

We tend to ‘prefer’ 1 hemisphere over the other◦‘dominance’ ◦reflected in the ways we learn best

LATERALIZATION & INTEGRATION!

Right vs. Left Handedness? Right vs. Left Handedness? Genetics

◦4/5 sets of identical twins have same handedness

levels of testosterone during pregnancy◦Boys 2 x more likely to be ‘lefties’

Handedness dev. prenatally Forcibly imposing a handedness can cause emotional probs & secretive behaviors

PARENTS WHO ARE LEFT HANDED

CHILD’S ODDS

Neither parent 1 in 50

One parent 1 in 6

Both parents 1 in 2

Stare @ the dot (1 min) – stare @ wall

‘‘SPLIT BRAIN’ SPLIT BRAIN’ STUDIESSTUDIESSeparate the 2 hem. by cutting the corpus callosum ◦Lessens severity/frequency of epileptic seizures

Creates 2 independently functioning cerebrums

Intelligence, personality, & emotions went unchanged… seem ‘normal’

This changes way people think about & deal w/ the world in 2 major ways: 1) touch: can’t label an object if it’s held in the left hand◦ word ‘spoon’ shown to lft eye… can’t say what it is but can pick up a spoon among other objects

◦Patients blindfolded & key put in lft hand… can’t say what it is but used it to open a lock

2) vision: can’t describe a picture if seen only by the left eye.

◦Nude pic shown to right eye… laughed & described what they saw

◦Nude pic shown to lft eye… only blushed & smile(emotional rxn)

BRAIN ANEURYSMBRAIN ANEURYSMBulging artery that can rupture1/15 ppl in U.S. will dev. an aneurysm:

◦10% - 15% ‘ruptures’ die before getting to a hospital

50% die w/in 30 days after rupture 50% survivors suffer permanent damagemost commonly detected btw ages 35 -

60 Women to men - 3:2 ratioGenetics, smoking, blood pressure,

ethnicity

STROKESSTROKES 3rd leading COD in U.S. ½ mill. ppl/each yr! Blockage of a blood vessel kills brain tissue

Impaired abilities depend on where it happens in the brain◦lang., coordination, numbness/paralysis of a part on 1 side of the body, hearing, decision-making, etc.

BRAIN PLASTICITYBRAIN PLASTICITYPlasticity: ability of the brain to adapt itself after trauma, alteration, or disease ◦strengthen neural connections @ synapses & est. new ones

When 1 part is damaged, another part of the brain may take over its functions (to a certain extent) – compensates!

How? Build new circuitry &/or alter existing◦Ex. Visual cortex in blind ppl

Childhood vs. adulthood

PRUNINGPRUNINGPruning:

◦Brain will cut some neural connections & “rewires” itself

◦The neurons w/o connections can no longer be accessed (‘lose’ that info)

Which ones are cut? ◦Genetics◦Experiences (don’t use it, you lose it)

How much, which ones, & in what ways the brain prunes can greatly affect cog. abilities

Connections that remain are stronger, faster, & more efficient than before!

Infancy & childhood◦brain “overproduces” neural connections (new experiences & rapid learning)

Adolescence◦big pruning period!

Stare @ the cross only

BATTLE OF THE SEXESBATTLE OF THE SEXES

MEN WOMEN3D perceptions targeted motor skills

Effects of brain trauma more devastating

recognizing patterns

Use more of the brain when processing language

*Patterns of brain functioning differs slightly*Sex or gender (?)

NEUROTRANSMITTERSNEUROTRANSMITTERS

CHEMICALS IN THE ENDINGS OF NEURONS THAT SEND INFO. ACROSS SYNAPSES TO ANOTHER NEURON

-- excitatory -- inhibitory

WHAT ARE THEY?WHAT ARE THEY?• Chemical signals (100+) • relay messages/info. from 1 neuron to

another• certain behaviors are assoc. w/

certain neurotransmitters• Each circuit specific to an activity • Mvmt circuit, pain circuit, pleasure

circuit, etc.Everything you do, feel, or think depends on neurotransmitters!!!!!!!

AcetylcholineAcetylcholineArousal (excitatory)Controls the expansion & contraction of muscles; movement◦Send info. from 1 nerve cell to another whenever we get ready to move some part of the body.

Disorders = Alzheimer’s, inability to make new memories, paralysis

NorepinephrineNorepinephrineArousal (excitatory), mood regulation, increases heart rate & contracts blood vessels, stimulates glands to release adrenaline

Disorder = depression; prolonged overproduction can cause ‘burn out’ ◦symptoms resemble paranoid schizophrenia

SerotoninSerotoninAffects sleep, mood/emotion regulation, appetite, aggression, sexuality, & impulse control

Body makes it from chemicals in certain foods (carbs, fruits, & veggies), sunlight, exercise

Men & women react diff’tly to dramatic drops in serotonin levels◦Men – more impulsive; women – more cautious & drop in mood

Disorders = SIDS; SAD; Depression

DopamineDopamineemotional functioning, motivation, reward◦Disorders = Parkinson’s Disease, Schizophrenia, addictions

Parkinson’s Disease◦Only disease that is caused by a shortage of a single neurotransmitter!

PARKINSON’S DISEASEPARKINSON’S DISEASEDegenerative brain disease that leads to a progressive loss of motor function◦Dopamine-producing brain neurons in an area of the brain involved in regulating body movement are destroyed

Muscle tremors, shakiness, body’s inability to control mvmt, diff. speaking

1 mill Ams – Muhammad Ali & Michael J. Fox◦Genetic factors (?)

GlutamateGlutamateNecessary for normal dev. & functioning

Memory, learning◦Strengthens synaptic/neural connections

Overactivity (too much glutamate) can kill neurons

Disorder = Neuron loss after a stroke or brain trauma (causes memory or skill loss), seizures

EndorphinsEndorphinsRelieve pain; produce feelings of well-being

& pleasureBody’s natural pain killers – fit into receptors

that pain messages fit into (block)Similar in chemical structure to narcotic

drugsOpiates (heroine, morphine, & opium) bind

to the neuron receptors that endorphins usually bind to. ◦Drugs alter brain chemistry & neural communication!

ENDOCRINE SYSTEMENDOCRINE SYSTEM

WHAT IS IT?WHAT IS IT?Endocrine system is the nervous system’s partner in controlling & coordinating the body’s functions. ◦Nervous system – neurotransmitters◦Endocrine system - hormones

Includes Pituitary Gland, Hypothalamus, Thyroid, Pineal gland, Pancreas, Adrenal Glands, Kidneys, Ovaries, Testes.

Some glands respond to nervous system messages too

WHAT DOES IT DO?WHAT DOES IT DO?Organs in the endocrine system (glands)

release hormones (chemical messengers) directly into the bloodstream ◦Communicate with other organs

physical dev, growth, metabolism, sexual behavior, moods, energy, insulin, maturation of reproductive system, stress/ fight-or-flight response (adrenaline & cortisol)

Differs in men & women (sex hormones)

GLAND / HORMONE

FUNCTION

Pituitary -- Growth hormone -- Oxytocin

Stimulates growth; Stimulates uterine contractions & milk production

Hypothalamus -- releasing factors

Part of the brain that stimulates the pituitary to release hormones

Pineal -- Melatonin Regulates sleep-wake cycles

Pancreas -- Insulin

Regulates blood sugar levels

Thyroid

Regulates metabolism, maturationToo much – irritability & anxietyToo little – sluggishness, weight gain, intellectual retardation in kids

GLAND / HORMONE

FUNCTION

Adrenal -- epinephrine (adrenaline)-- norepinephrine (noradrenaline)

helps body cope w/ stress; speeds up body processes; stimulates liver to release sugars

Ovaries -- estrogen -- progesterone

Female sexual maturation & menstrual cycle (PMS) Helps maintain pregnancy

Testes -- testosterone

Promotes sperm production; sex drive; male sexual maturation; makes males during prenatal period

IMMUNE SYSTEMIMMUNE SYSTEM

serves as both a sensory & surveillance system

Detects & destroys unwanted cells and foreign bodies (remembers them)

Underresponsive = bacteria & malignant cells run rampant in the body (death?)

Overresponsive = attack & kill normal cells in the body (neurons too)

Sleepiness, nausea, fever result from chemicals that act directly on the brain.

PERCEPTION! PERCEPTION! Seeing is believing? Perception – how you become aware of, know, or identify something (senses)

Our mental programming intervenes in everything we perceive.

Our minds arrange an image, sound, info to render it ‘acceptable’, or to make it match our knowledge and beliefs.

Everyone has their OWN perception!

ColorblindnessColorblindnessPeople with normal color vision can perceive

numbers formed by patterns of colored dots in every circle. If you do not see some of the numbers, you should have your eyes checked and consider working in a job where color discrimination is not critical.

Approximately 6%-8% of people of European descent, 4%-6% of people of Asian descent, and 2%-4% of people of African descent have some type of defective color vision.

There are no curved lines in these figures. You can use a ruler to check it out.The diagonal patterns created by the tiny squares distort the perception of the pictures

Flag IllusionFlag Illusion

The illusion works because staring at the blue, green and black fatigues cells in our eye (and brain) that are specialized for these colors.

When we look at the white wall, other cells which respond to the complementary colors (red, white and blue) are now more active than the fatigued cells and so we experience these new colors in the after-image.

Ths s prttey cool.

Movement… When there is none! Movement… When there is none!

There is nothing in motion… what is happening?

Afterimages of complementary colors create apparent movement in our peripheral visionas our eyes shift across the page.

AfterimagesAfterimagesAn afterimage is a visual impression that

remains in the retina after the initial stimulus is removed. The afterimage always has colors that are complementary to those of the original image. Look steadily at the cross in the center of the picture to see an afterimage.

The effect is due to retinal fatigue which occurs when the afterimage of an object cancels the stimulus of the object on the retina. The effect is most pronounced when the objects do not have well-defined edges that are detectable by small eye movements.