Chapter 6Body & Behavior

Section 1

The Nervous System

The Organization of the Nervous System

Nervous systemNervous system

Peripheral nervous Peripheral nervous systemsystem

Central nervous Central nervous system (CNS)system (CNS)

AutonomicAutonomicnervous systemnervous system

SomaticSomaticnervous systemnervous system

SympatheticSympatheticnervous systemnervous system

Parasympathetic Parasympathetic nervous systemnervous system

Two Divisions of the Nervous System

• Central Nervous System (CNS)– Made up of the brain and spinal cord.

• Peripheral Nervous System (PNS)– Nerves branching out from the

spinal cord.

Two Divisions of the PNS

• Somatic NS – controls voluntary behaviors

• Autonomic NS – controls involuntary behaviors

– Sympathetic – “fight or flight”

– Parasympathetic – “rest and digest”

The Neural Impulse

Synapse

- The gap between neurons.

Neurotransmitters

• Neurotransmitters – Chemical messengers that relay neural messages across the synapse.

ANIMATION

3 Types of Neurons:

-Sensory (afferent) neurons - carry messages from sense receptors towards the brain.

-Motor (efferent) neurons - carry messages from brain toward muscles and glands.

-Interneurons - carry messages between nerve cells.

Section 2

Studying the Brain

3 Parts of the Brain:

1. Forebrain

2. Midbrain

3. Hindbrain

Forebrain

• A part of the brain that covers the brain’s central core.

Includes:• Thalamus• Hypothalamus• Cerebral cortex• Cerebrum• Limbic system• Amygdala • Hippocampus

ForebrainThalamus

– Integrates sensory input; relay station for all the information that travels to and from the brain.

Hypothalamus– Controls functions such as hunger, thirst, and sexual

behavior; also controls temperature.

Cerebral cortex– Outer layer of the forebrain; gives you the ability to learn and

store complex and abstract information.

ForebrainCerebrum

– Inner layer of the forebrain.

Limbic system– Various structures in the brain that regulate our emotions

and motivations (includes: amygdala, hippocampus)

Midbrain

• A small part of the brain above the pons that integrates sensory information and relays it upward.

RAS:• Alerts the rest of the brain

to incoming signals and is involved in the sleep/wake cycle.

Hindbrain

• Located at the rear base of the skull; involved in the basic processes of life.

Includes:• Cerebellum• Medulla• Pons

Hindbrain

Cerebellum– Helps control posture, balance, and voluntary

movements.

Medulla– Controls breathing, heart rate, and other reflexes.

Pons– Produces chemicals the body

needs for sleep.

Parts of the Brain Parts of the Brain

• Thalamus

• Pons

• Cerebellum

• Medulla

• Brain stem

The 4 Lobes:Frontal lobe

(organization, planning, creative thinking)

Parietal lobe(touch sensations)

Occipital lobe

(visual signals)

Temporal lobe

(hearing, speaking)

Left v Right Hemisphere

Split-Brain Operations

• A treatment option for those suffering from grand mal seizures.

– Separating the brain hemispheres by severing the corpus callosum lessons the number and severity of seizures. Mr. Split-Brainy

Video

How do we study the BRAIN?

1. Recording (EEG)2. Stimulation3. Lesions4. Accidents - Phineas Gage5. Images

(CAT, PET, MRI)

Recording

• Electroencephalograph (EEG):– A machine used to record electrical activity in

the brain.

Stimulation

• Wilder Penfield stimulated the brains of his patients during surgery to determine what functions the various parts of the brain perform.

– He was able to localize the malfunctioning parts of the brain.

Lesions

• Lesions: cutting or destroying parts of the brain.

• If the animal behaves differently after the operation, we can assume the destroyed brain area is involved with that type of behavior.

Accidents

• Psychologists can learn about the brain when people are involved in accidents.

• Psychologists try to draw a connection between the damaged parts of the brain and a person’s behavior.

Accidents – Phineas Gage

• His frontal lobe was damaged, which caused his personality to change*

• He became short-tempered and said inappropriate things.

• Therefore, damage to the frontal lobe prevents censoring of thoughts and ideas.

Images

• CAT (computerized axial tomography)

– Used to pinpoint injuries in the brain.• PET (positron emission tomography)

– Used to see which brain areas are being activated while performing tasks.

• MRI (magnetic resonance imaging)

– Used to study brain structures.

Section 3

Copyright © Allyn & Bacon 2007

The Endocrine System(the body’s chemical messenger system)

Endocrine System - Glands

• Pituitary gland– Control center of the

endocrine system that secretes a large number of hormones.• Known as the master

gland.• Produces growth

hormones.

Video Clip - Gigantism

Endocrine System - Glands

• Thyroid gland– Produces the hormone

thyroxin.– Hypothyroidism – makes

people feel lazy and lethargic.

– Hyperthyroidism – causes people to lose weight and be overactive.

Endocrine System - Glands

• Adrenal glands– Release adrenaline into the bloodstream.

• Causes heart rate and breathing to increase• Heightens emotions (fear, anxiety)

Endocrine System - Glands

Sex glands:– Ovaries

• Produce eggs and the female hormones estrogen and progesterone.

– Testes• Produce sperm and

the male sex hormone testosterone.

Hormones vs NeurotransmittersHormones vs Neurotransmitters• Endocrine System

– Glands release hormones into the bloodstream.

• Nervous System– Neurons release

neurotransmitters to either excite or inhibit other neurons.

Section 4

Heredity & Environment

Heredity• The genetic transmission of

characteristics from parents to their offspring.

Nature v Nurture

• Nature– The characteristics a

person inherits– Biological makeup– GENETICS

Sir Francis Galton

• Nurture– ENVIRONMENT– Family, culture,

education, and individual differences

John Watson

Genes – the basic building blocks of heredity.

Twin Studies

• Identical twins– Come from ONE fertilized egg; also called

monozygotic twins.

• Fraternal twins– Come from TWO different eggs

fertilized by two different sperm; also called dizygotic twins.

WHY STUDY TWINS???

End of Chapter 6