Chapter 3Chapter 3

Biology and BehaviorBiology and Behavior

I. Nervous SystemI. Nervous System

Nervous System:Nervous System: Involved in thinking, Involved in thinking, dreaming, feeling, moving and much more.dreaming, feeling, moving and much more.

Two Main PartsTwo Main Parts

Central Nervous System:Central Nervous System: brain and brain and spinal cord.spinal cord.

Peripheral Nervous System:Peripheral Nervous System: nerve cells nerve cells that send messages between the that send messages between the central nervous system & all the parts central nervous system & all the parts of the body.of the body.

II. Central Nervous SystemII. Central Nervous System

Extends from the brain down the backExtends from the brain down the back Responsible for spinal reflexesResponsible for spinal reflexes Example:Example: touch a hot stove, message touch a hot stove, message

sent to spinal cord, message sent to sent to spinal cord, message sent to hand to let go.hand to let go.

II. Peripheral Nervous SystemII. Peripheral Nervous System

Two Divisions:Two Divisions: 1) 1) Somatic:Somatic: Transmits sensory Transmits sensory

messages to central nervous system. messages to central nervous system. (activated by touch, pain, temp (activated by touch, pain, temp changes, etc)changes, etc)

2) 2) Autonomic:Autonomic: Regulates the bodies Regulates the bodies vital functions (heartbeat, breathing, vital functions (heartbeat, breathing, digestion, & blood pressure)digestion, & blood pressure)

Autonomic divides into twoAutonomic divides into two

1) 1) Sympathetic:Sympathetic: Activated during Activated during action action (“fight or flight”)(“fight or flight”)

2) 2) Parasympathetic:Parasympathetic: restores the restores the body’s reserves of energy after an body’s reserves of energy after an action has occurred. (heart rate & action has occurred. (heart rate & blood pressure normalized, breathing blood pressure normalized, breathing is slowed, digestion returns to normal)is slowed, digestion returns to normal)

Figure 2.2 A motor neuronMyers: Psychology, Eighth EditionCopyright © 2007 by Worth Publishers

III. Neurons: Tree like III. Neurons: Tree like StructuresStructures

Run through our entire body and Run through our entire body and communicate with each othercommunicate with each other

Send & receive messages from other Send & receive messages from other structures in the body (muscles & glands)structures in the body (muscles & glands)

More than 100 Billion neurons (mostly found More than 100 Billion neurons (mostly found in the brain)in the brain)

A. Cell BodyA. Cell Body

Cell Body: produces energy that fuels Cell Body: produces energy that fuels the activity of the cellthe activity of the cell

Can have many dendrites but usually Can have many dendrites but usually only one axononly one axon

B. Dendrites B. Dendrites (Branches)(Branches)

Receive information from other Receive information from other neurons and pass the message neurons and pass the message through the cell bodythrough the cell body

C. Axon C. Axon (Trunk)(Trunk)

Carries messages awayCarries messages away

D. MyelinD. Myelin

Myelin:Myelin: covers axon covers axon White fatty substance that insulates White fatty substance that insulates

and protects the axon.and protects the axon. Helps to speed up transmission of Helps to speed up transmission of

message.message.

E. Axon TerminalsE. Axon Terminals

Axon Terminals:Axon Terminals: Smaller branches at Smaller branches at the end of the axon.the end of the axon.

F. SynapseF. Synapse

Area between the axon terminal and Area between the axon terminal and another dendrite.another dendrite.

New synapses can develop between New synapses can develop between neurons that were not previously neurons that were not previously connected, as when we learn connected, as when we learn something new.something new.

IV. Neurotransmitters: IV. Neurotransmitters: ChemicalsChemicals

Stored in sacs in the axon terminalsStored in sacs in the axon terminals When a neuron fires, it releases When a neuron fires, it releases

neurotransmitter sacs.neurotransmitter sacs. Different chemicals cause different Different chemicals cause different

physical reactionsphysical reactions Example: Example:

– Acetylcholine: involved in controlling our Acetylcholine: involved in controlling our musclesmuscles

– Dopamine: motor behavior: too much= Dopamine: motor behavior: too much= Schizophrenia, too little = Parkinson’s disease.Schizophrenia, too little = Parkinson’s disease.

V. The Endocrine SystemV. The Endocrine System

Endocrine System:Endocrine System: consists of glands that consists of glands that secrete substances, called hormones. secrete substances, called hormones.

Pituitary Gland: Pea sized “master Pituitary Gland: Pea sized “master gland”gland”

Growth:Growth: regulates the growth of muscles, regulates the growth of muscles, bones, and other glands.bones, and other glands.

Prolactin:Prolactin: stimulates milk production in stimulates milk production in womenwomen

Oxytocin:Oxytocin: stimulates labor in women stimulates labor in women

Thyroid GlandThyroid Gland

Produces thyroxin:Produces thyroxin: affects the body’s affects the body’s metabolismmetabolism

Adrenal Glands: located above the Adrenal Glands: located above the kidneyskidneys

Cortical steroids:Cortical steroids: increase resistance to increase resistance to stress & promote muscle developmentstress & promote muscle development

Causes liver to release stored sugar, Causes liver to release stored sugar, making energy available for emergenciesmaking energy available for emergencies

Adrenaline & noradrenalin:Adrenaline & noradrenalin: helps to cope helps to cope with stressful situationswith stressful situations

Testes & Ovaries: produces Testes & Ovaries: produces testosterone, estrogen, and testosterone, estrogen, and

progesteroneprogesterone Testosterone:Testosterone: Male sex hormone, but found Male sex hormone, but found

in females in small amountsin females in small amounts A. After 1A. After 1stst 8 weeks of development: 8 weeks of development:

influences the sex of a childinfluences the sex of a child B. B. Adolescence:Adolescence: aids in muscle & bone aids in muscle & bone

growth, primary & secondary sex growth, primary & secondary sex characteristics. (Reproduction/body hair)characteristics. (Reproduction/body hair)

Estrogen & Progesterone: female Estrogen & Progesterone: female sex hormone, but found in males in sex hormone, but found in males in

small amountssmall amounts A. A. Estrogen:Estrogen: primary and secondary sex primary and secondary sex

characteristic (body hair & breast characteristic (body hair & breast development)development)

B. B. Progesterone:Progesterone: stimulates growth of stimulates growth of female reproductive organs & helps prepare female reproductive organs & helps prepare the body for pregnancythe body for pregnancy

C. C. Estrogen & Progesterone:Estrogen & Progesterone: regulate regulate menstrual cyclemenstrual cycle

Higher levels of estrogen seem to be Higher levels of estrogen seem to be connected with optimal cognitive functioning connected with optimal cognitive functioning & feeling of well-being among women.& feeling of well-being among women.

Brain AnatomyBrain Anatomy

Frontal Lobe:Frontal Lobe:

Problem solving, attention, judgment, Problem solving, attention, judgment, reflection, coordination of movement, sense reflection, coordination of movement, sense of smell, muscle movements, physical of smell, muscle movements, physical reaction, libido. reaction, libido.

Occipital LobeOccipital Lobe

Vision, ReadingVision, Reading

Parietal Lobe:Parietal Lobe:

Sense of touch, response to internal stimuli, Sense of touch, response to internal stimuli, sensory combination and comprehension, sensory combination and comprehension, some language & reading functions, some some language & reading functions, some visual functions.visual functions.

Temporal Lobe:Temporal Lobe:

Auditory memories, some hearing, visual Auditory memories, some hearing, visual memories, some vision pathways, music, memories, some vision pathways, music, fear, some language, some speech, some fear, some language, some speech, some behaviors & emotions, sense of identity.behaviors & emotions, sense of identity.

Cerebellum:Cerebellum:

Balance, posture, cardiac, respiratory, Balance, posture, cardiac, respiratory, vasomotor centersvasomotor centers

Sensory Area:Sensory Area:

Legs, torso, head, arms, hands, fingers, Legs, torso, head, arms, hands, fingers, face, lips, tongueface, lips, tongue

Motor Area:Motor Area:

Toes, knees, hips, shoulders, wrists, fingers, Toes, knees, hips, shoulders, wrists, fingers, neck, eyes, jaw.neck, eyes, jaw.

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Heredity: Our genetic backgroundHeredity: Our genetic background

Heredity:Heredity: the transmission of characteristics the transmission of characteristics from parents to offspring.from parents to offspring.

**Can determine our behavior & physical **Can determine our behavior & physical appearance**appearance**

Genes:Genes: the basic building blocks of heredity. the basic building blocks of heredity. **One gene is given by one parent, & one is **One gene is given by one parent, & one is

given by the other parent.given by the other parent.

Chromosomes:Chromosomes: made of made of deoxyribonucleic acid (DNA)deoxyribonucleic acid (DNA)

** Normal human cells contain 46 ** Normal human cells contain 46 chromosomes.chromosomes.

>23 from one parent, 23 from the other >23 from one parent, 23 from the other parentparent

> 22 chromosomes are the same in males > 22 chromosomes are the same in males and females, the 23 is the sex chromosomeand females, the 23 is the sex chromosome

** Males=XY 23** Males=XY 23rdrd chromosome, Female= XX chromosome, Female= XX 2323rdrd chromosome chromosome

Nature-Nurture DebateNature-Nurture Debate

Nature:Nature: genetics influences a person’s genetics influences a person’s personality mostpersonality most

**Biological groundwork that prepares a **Biological groundwork that prepares a person to develop in certain waysperson to develop in certain ways

Nurture:Nurture: environment influences a person’s environment influences a person’s personality most.personality most.

**Family, education, culture, living **Family, education, culture, living conditions, etc…conditions, etc…

Kinship Studies: helps to determine Kinship Studies: helps to determine what role heredity & environment what role heredity & environment

playplay ** Twins=100%,Parent/Child=50%, ** Twins=100%,Parent/Child=50%,

Brothers/Sisters=50%, Blood Aunts-Brothers/Sisters=50%, Blood Aunts-Uncles/Niece-Nephews=25%, 1Uncles/Niece-Nephews=25%, 1STST cousins= cousins= 12.5%12.5%

**Studies certain traits or behavioral **Studies certain traits or behavioral patterns in individuals and then compares patterns in individuals and then compares them to those of relativesthem to those of relatives

Example: twins & adoptee studiesExample: twins & adoptee studies

Twins:Twins:

Identical Twins:Identical Twins: share 100% of genes share 100% of genes ** have same shyness & activity levels, ** have same shyness & activity levels,

irritability, sociability, & happinessirritability, sociability, & happiness ** more likely to share psychological ** more likely to share psychological

disorders like autism & schizophreniadisorders like autism & schizophrenia Fraternal Twins:Fraternal Twins: share 50% of genes share 50% of genes

Twins Reared Apart:Twins Reared Apart:

** Many shared common psychological & ** Many shared common psychological & personality traits like: intelligence, personality traits like: intelligence, traditionalism, risk avoidance, aggression, traditionalism, risk avoidance, aggression, and leadership.and leadership.

** shared same mannerisms such as how ** shared same mannerisms such as how they stand or sit.they stand or sit.