Biological Biological Bases of Bases of BehaviorBehavior

The Human Nervous System, Neurons, and the BRAIN!!!

Modules 4-5

Phineas Gage

Phineas Gage !Phineas Gage !In 1848, Gage, 25, was the foreman of a crew cutting a railroad bed in Cavendish, Vermont. On September 13, as he was using a tamping iron to pack explosive powder into a hole, the powder detonated. The tamping iron—43 inches long, 1.25 inches in diameter and weighing 13.25 pounds—shot skyward, penetrated Gage’s left cheek, ripped into his brain and exited through his skull, landing several dozen feet away. Though blinded in his left eye, he might not even have lost consciousness, and he remained savvy enough to tell a doctor that day, “Here is business enough for you.” Gage’s initial survival would have ensured him a measure of celebrity, but his name was etched into history by observations made by John Martyn Harlow, the doctor who treated him for a few months afterward. Gage’s friends found him“no longer Gage,” Harlow wrote. The balance between his “intellectual faculties and animal propensities” seemed gone. He could not stick to plans, uttered “the grossest profanity” and showed “little deference for his fellows.” The railroad-construction company that employed him, which had thought him a model foreman, refused to take him back. So Gage went to work at a stable in New Hampshire, drove coaches in Chile and eventually joined relatives in San Francisco, where he died in May 1860, at age 36, after a series of seizures.

Read more: http://www.smithsonianmag.com/history-archaeology/Phineas-Gage-Neurosciences-Most-Famous-Patient.html#ixzz2g62z2JoU

““I am a I am a neuronneuron””• A nerve cell; the basic building block of the

nervous system• NEURONS have 3 tasks:1. Receive information2. Carry information down its length3. Pass the information on to the next neuron• We have over 100 billion neurons! Most of the

them are in the BRAIN!

Parts of the NEURON!Parts of the NEURON!• Dendrites: the BRANCHING extensions of a

neuron that receive information and conduct impulses toward the cell body (SOMA)

• Axon: the extension of a neuron through which neural impulses are sent; covered in MYELIN SHEATH

• Axon terminals (buttons): the end point of a neuron where neurotransmitters are stored

DO NOWDO NOWHand in terms…make sure they are numbered!!!

Take out notebooks!

Electrochemical Electrochemical

CommunicationCommunication

HOW DOES A NEURON FIRE???

1.Action potential: an impulse caused by a neuron firing2.Refractory period: after a neuron fires, it needs to recharge before it can fire again3.Resting potential: when the neuron is “charged” and waiting for another action potential to start

Wait? Whattttttt?Wait? Whattttttt?How can I remember ALL of this neural communication stuff????

Think about a toilet bowl!

Types of Neurons!Types of Neurons!• Sensory neurons: nerve cells that

carry information received by the senses TO the CNS

• Motor neurons: nerve cells that carry information FROM the CNS to the muscles and glands, and influence their functioning

• Interneurons: nerve cells in the brain and spinal cord responsible for processing information

WAIT! WAIT! We know how

messages travel DOWN the neuron but then what??? How do neurons

communicate with one another?

Communication between Communication between NeuronsNeurons

As the electrical impulse travels down to the neuron’s axon terminals, a

NEUROTRANSMITTER is released across the SYNAPSE to the receptor

sites on the dendrites of the next neuron.

Just do it? Or Nahhh…Just do it? Or Nahhh…Neurotransmitters either have an excitatory effect or an inhibitory effect

EXCITATORY: GOOOOOOOOOOO!!!!!

INHIBITORY: STOP!!!!!!

AgonistA drug that boosts the effect of a neurotransmitter

Examples:ACh – black widow spider venom

AntagonistA drug that blocks the effect of a neurotransmitter

Examples: ACh - curare

Human Nervous Human Nervous System

• Human nervous system is involved in thinking, dreaming, feeling, moving

- regulates our internal functions• TWO main parts:• Central Nervous System (CNS) – consists of

the brain and spinal cord• Peripheral Nervous System (PNS) – consists of

the nerve cells that send messages between the CNS and all the parts of the body

SSomatic Nervous omatic Nervous SystemSystem

• Transmits sensory messages to the CNS• Activated by touch, pain, changes in

temperature, changes in body temperature• Alerts us that parts of the body have moved or

changed positions• Sends messages to the muscles and glands

helping us maintain posture and balance/skeletal system

Autonomic Nervous Autonomic Nervous SystemSystem

• Autonomic “occurring involuntarily”• Regulates the body’s vital functions• EX: heartbeat, breathing, digestion, blood

pressure• TWO divisions:1. Sympathetic2. parasympathetic

Sympathetic • Activated when

someone is going into action; prepares body for “fight or flight”

- Suppresses digestion; increases heart rate and respiration, elevates blood pressure

*Remember “S” for stress

Parasympathetic• Restores the

body’s reserves of energy after an action

* Remember “P” for peace

The BRAIN!!!!!!!!!!!!!!!The BRAIN!!!!!!!!!!!!!!!

How do we STUDY How do we STUDY it???it???

Scans that show STRUCTURE•CAT scan: x-ray photographs•MRI: uses magnetic fields and radio waves to produce imagesScans that show FUNCTION!•EEG: records electrical activity•PET scan: visual display of activity; glucose levels•fMRI: shows activity (blood flow & oxygen) AND images

Cerebral CortexCerebral Cortex• Newer neural networks

within the “cerebrum” – 2 hemispheres

• Covering like bark on a tree – cerebral cortex

• Makes us distinctively human

Cerebral CortexCerebral Cortex• An intricate fabric of interconnected neurons

that make up the body’s ultimate control and information-processing center

- Longitudinal fissure: the long crevice that divides the cerebral cortex into the left and right hemispheres

- Corpus callosum: large band of neural tissue that connects the two hemispheres so they can communicate

LOBES of the BRAINLOBES of the BRAIN•Frontal•Parietal•Temporal•Occipital

FRONTAL•It is concerned with emotions, reasoning, planning, movement, and parts of speech. It is also involved in purposeful acts such as creativity, judgment, problem solving, and planning.•Motor cortex•Broca’s area

PARIETAL•They are connected with the processing of nerve impulses related to the senses, such as touch, pain, taste, pressure, and temperature. They also have language functions.•Sensory cortex

TEMPORAL•The temporal lobes are responsible for hearing, memory, meaning, and language. They also play a role in emotion and learning. The temporal lobes are concerned with interpreting and processing auditory stimuli.•Wernicke’s area

OCCIPITAL•The occipital lobe is involved with the brain's ability to recognize objects. It is responsible for our vision.

The BRAINSTEM-Medulla

-Reticular formationThe THALAMUS

The CEREBELLUMThe Limbic System-HYPOTHALAMUS-HIPPOCAMPUS

-AMYGDALA

Review! (Answer in Review! (Answer in your notebooks!)your notebooks!)

1. How do neurons communicate?? (include structures involved!)

2. What is action potential?! (TOILET)3. AHHHHHHH! You scared me! My body is

STRESSED! What NERVOUS SYSTEM is being activated? What part of the BRAIN is involved in the emotion FEAR?

4. What LOBE deals with SENSORY information?5. It’s sooooooo cold in here! What part of my brain

will regulate my body temperature??**TAKE OUT LOBE COLORING from yesterday!**

LEFT vs. RIGHTLEFT vs. RIGHTRIGHTSpatial abilitiesArt

LEFTLanguage…Broca’s area: left frontal lobe; speechWernicke’s area: left temporal lobe; comprehension

Psychology’s Psychology’s Superheroes!! Superheroes!!

BROC BRIGHT!BROC BRIGHT!You get it right.

Pronouncing it will be outta sight.Speech impediment, dyslexia…just a

few to name.Even if you’re trying to learn a new language the fact still remains the

same.Helping you perfect your language is

the name of my game.

What is a headache?What is a headache?Concussions

Concussions in Sports

PITUITARYPITUITARY• “master gland” controlled by hypothalamus• Growth hormone – regulates growth of muscles,

bones, glands• Prolactin – stimulates production of milk in

nursing women• Oxytocin – stimulates labor

THYROIDTHYROID• Thyroxin – affects the body’s metabolism• Hypothyroidism – too little• Hyperthyroidism – too much

ADRENALADRENAL• Adrenaline & noradrenaline – help arouse body

and cope with stressful situations• Adrenaline also plays a role in emotions…can

intensify fear and anxiety

TESTES & OVARIESTESTES & OVARIES• Testosterone – role in development; primary and

secondary sex characteristics• Estrogen/progesterone

HeredityHeredity• Heredity – transmission of characteristics from

parents to offspring- Plays a key role in development of traits- Vital in transmission of physical traits: height, hair

texture, eye color- Related to some extent in psychological traits - shyness, leadership, aggressiveness, interest in

arts/crafts- Research have found it is factor – anxiety,

depression, schizophrenia, bipolar, alcoholism

- - normal humans : 46 chromosomes- - 22 of 23 pairs are similar between

males/females- - 23rd pair – sex chromosome XX XY- - females have 2 X so they always pass an X;

male chromosome determines sex- Abnormalities: Turner’s (single X); Klinefelter’s

(extra X); Down Syndrome (extra chromosome on the 21st pair)

Nature vs. NurtureNature vs. Nurture• Nature what is inherited• Nurture environmental factors

• Which has more of any influence???• Should genetic counseling be mandatory???

StudiesStudies• Kinship studies – 50% genes • Twin studies – 100%; psychological disorders;

temperament• Adoptee studies – more like biological parents or

adopted parents?• Twins reared apart (studies!) • Correlation coefficient for IQ – 0.69 for

identical twins reared apart; 0.88 identical twins living together

Figure 3.27Genetic relatedness. Research on the genetic bases of behavior takes advantage of the different degrees of genetic relatedness between various types of relatives. If heredity influences a trait, relatives who share more genes should be more similar with regard to that trait than more distant relatives, who share fewer genes. Comparisons involving various degrees of biological relationships will come up frequently in later chapters.

Figure 3.30Twin studies of intelligence and personality. Identical twins tend to be more similar than fraternal twins (as reflected in higher correlations) with regard to general mental ability and specific personality traits, such as extraversion. These findings suggest that intelligence and personality are influenced by heredity. (Intelligence data from McGue et al., 1993; extraversion data based on Loehlin, 1992)