The Nervous System: The Basic Structure - Eastern …web.eccrsd.us/walkerm/public/Walker/Accelerated... · · 2012-11-26The Nervous System: The Basic Structure Understand that the

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Chapter Introduction

Section 1: The Nervous System: The Basic Structure

Section 2: Studying the Brain

Section 3: The Endocrine System

Section 4: Heredity and Environment

Chapter Objectives · Section 1 The Nervous System: The Basic Structure

Understand that the nervous system helps us know how messages that are sent to and from the brain cause behavior.

Chapter Objectives · Section 2 Studying the Brain

Discuss the many parts of the brain that work together to coordinate movement and stimulate thinking and emotions.

Chapter Objectives · Section 3 The Endocrine System

Explain how the endocrine system controls and excites growth and affects emotions and behavior.

Walker_Maryann Thursday, January 6, 2011 12:16:22 PM ET

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Chapter Objectives · Section 4 Heredity and Environment Identify heredity and environment and analyze how they affect your body and behavior.

Main Idea

Learning about the nervous system helps us know how messages that are sent to and from the brain cause behavior.

•  Nervous system

•  central nervous system (CNS)

•  Brain

•  spinal cord

• Peripheral nrvous nervous system (PNS)

•  somatic nervous system (SNS)

•  autonomic nervous system (ANS)

Vocabulary

•  Nervous system

•  central nervous system (CNS)

•  peripheral nervous system (PNS)

•  spinal cord

•  neurons

•  synapse

•  neurotransmitters

•  somatic nervous system (SNS)

•  autotomic nervous system (ANS)


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Objectives

•  Identify the parts of the nervous system.

•  Describe the functions of the nervous system.

How the Nervous System Works

•  The nervous system controls your emotions, movements, thinking, and behavior—almost everything you do.

•  It is divided into two parts:

–  The central nervous system (CNS)—the brain and spinal cord.

–  The peripheral nervous system (PNS)—these small branches of nerves conduct information from the bodily organs to the CNS and take information back to the organs.

How the Nervous System Works (cont.)

•  All parts of the nervous system are protected in some way (the skull protects the brain and so forth).

The Nervous System

•  Neurons are the long, thin cells of nerve tissues along which messages travel to and from the brain (much like a flame travels along a firecracker fuse).


•  Transmission between neurons, or nerve cells, occurs whenever the cells are stimulated past a minimum point and emit a signal.

Anatomy of Two Neurons


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•  Neurons have four basic parts:

–  Dendrites

–  Cell body

–  An axon

–  Axon terminals


•  A white, fatty substance called the myelin sheath insulates and protects the axon from some neurons.

•  A synapse is a junction or connection between the neurons.


The Synapse

•  A neuron transmits its impulse or message to another neuron across the synapse by releasing neurotransmitters.

–  Neurotransmitters can excite the next neuron or stop it from transmitting.

–  The synapse only allows signals to move in one direction.


•  There are many different neurotransmitters including:

–  Norepinephrine

–  Endorphin

–  Acetylcholine

–  Dopamine

–  Serotonin



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•  The actual destination of nerve impulses is limited by what tract in the nervous system they are on.

–  Ascending tracts carry sensory impulses to the brain.

–  Descending tracts carry motor impulses from the brain.


•  There are different types of neurons:

–  Afferent (sensory)—relay messages from the sense organs to the brain.

–  Efferent (motor)—send signals from the brain to the glands and muscles.

–  Interneurons—process signals connecting only to other neurons.


•  Somatic nervous system (SNS)—the part of the peripheral nervous system that controls voluntary movement of skeletal muscles.

•  Autonomic nervous system (ANS)—the part of the peripheral nervous system that controls involuntary internal biological functions.


•  The ANS has two parts:

–  The sympathetic nervous system

–  The parasympathetic nervous system



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A.  A B.  B C.  C D.  D

How many basic parts does a neuron have?

A. One

B. Two

C. Three

D. Four A.  A B.  B C.  C D.  D

How many basic parts does a neuron have?

A. One

B. Two

C. Three

D. Four – You’re right!

Main Idea

There are many parts in the human brain that work together to coordinate movement and stimulate thinking and emotions.

Vocabulary

•  hindbrain

•  midbrain

•  forebrain

•  lobes

•  electroencephalograph (EEG)

•  computerized axial tomography (CT)

•  positron emission tomography (PET)

•  magnetic resonance imaging (MRI)


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Objectives

•  Identify the structure and functions of the human brain.

•  Discuss the different ways psychologists study the brain.

The Three Brains

•  The brain is composed of three parts:

–  The

–  The

–  The

The Parts of the Brain

The Three Brains

•  The brain is composed of three parts:

–  The forebrain

–  The midbrain

–  The hindbrain

The Parts of the Brain

FOREBRAIN The higher thinking processes. Main concern of Psychology.

  Cerebral _________

  outer layer

  complex abilities

  ____ inch thick

  Cerebrum – inner layer – covers __________system

  Limbic system – regulates emotions and motivation

–  Hypothalamus - controls h_____, t________, s__, temperature responses

–  Amygdala – V____________ emotions such as rage and fear

–  Thalamus – relays sensory input – except for ______l

–  Hippocampus - ______________

The Cerebral Cortex


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FOREBRAIN The higher thinking processes. Main concern of Psychology.

  Cerebral cortex

  outer layer

  complex abilities

  ¼ inch thick

  Cerebrum – inner layer – covers limbic system

  Limbic system – regulates emotions and motivation

–  Hypothalamus - controls hunger, thirst, sex, temperature responses

–  Amygdala – violent emotions such as rage and fear

–  Thalamus – relays sensory input – except for smell

–  Hippocampus - memories

The Cerebral Cortex The Three Brains (cont.)

•  The cerebrum is two hemispheres connected by a band of fibers called the corpus callosum.

•  Each cerebral hemisphere has deep grooves, some of which mark regions, or lobes (the different regions into which the cerebral cortex is divided).

)

There are four lobes in the cerebral cortex

The Three Brains (cont.)

•  The right and left hemispheres of the brain complement and help each other.

•  They are roughly mirror images of each other.

Functions of the Brain’s Hemispheres


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•  Each hemisphere is connected to one-half of the body in crisscross fashion (the right side of the brain controls the left side of the body and vice versa).



•  The right side controls:

–  Visual and spatial relations

–  Perceptual tasks

–  Recognition of patterns

–  Creativity and intuition



•  The left side controls:

–  Speech

–  Mathematical ability

–  Calculation

–  Logic



•  Severing the corpus callosum can decrease the severity and number of grand mal seizures a person with epilepsy experiences.

•  This results in a split brain—the person has two brains that operate independently of each other.

Roger Wolcott Sperry


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A.  A B.  B C.  C

Which part of the brain controls your heart rate?

A. Hindbrain

B. Midbrain

C. Forebrain A.  A B.  B C.  C

Which part of the brain controls your heart rate?

A. Hindbrain 1.  Location – rear base of skull 2.  Includes

a)  Cerebellum – posture, balance, voluntary movements

b)  Medulla – breathing, heart rate, some reflexes

c)  Pons – bridge between spinal cord and brain; sleep chemicals

HINDBRAIN How Psychologists Study the Brain

•  Psychologists who study the brain are known as physiological psychologists, psychobiologists, or neuroscientists.


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How Psychologists Study the Brain (cont.)

•  The methods used to explore the brain include:

–  Recording with an electroencephalograph (EEG)

–  Stimulation

–  Lesioning

–  Accidents

How Psychologists Study the Brain (cont.)

•  Imaging is also used to study the brain:

–  Computerized axial tomography (CT)

–  Positron emission tomography (PET)

–  Magnetic resonance imaging (MRI)

Brain Activity on a PET Scan

Main Idea

The endocrine system controls and excites growth and affects emotions and behavior in people.

Vocabulary

•  endocrine system

•  hormones

•  pituitary gland


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Objectives

•  Describe the endocrine system.

•  Identify hormones and their function in the endocrine system.

The Endocrine Glands

•  The endocrine system is a chemical communication system that uses hormones to send messages through the bloodstream.

•  Hormones—chemical substances that carry messages through the body in blood.

The Endocrine System

The Endocrine Glands (cont.)

•  Hormones affect:

–  your behavior.

–  the growth of bodily structures such as muscles and bones.

–  your metabolic processes.

–  how your body acts in a stressful situation.

–  the brain (your moods and drives).

–  the differences between boys and girls.


•  The pituitary gland is the center of control of the endocrine system and secrets a large number of hormones.

•  It is directed by the hypothalamus.


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•  These hormone messages regulate cell metabolism and control growth and reproduction.

•  The thyroid gland produces the hormone thyroxine, which stimulates certain chemical reactions that are important for all tissues of the body.


•  The adrenal glands become active when a person is angry or frightened.

•  They release epinephrine and norepinephrine, which cause the heartbeat and breathing to increase in speed.


•  There are two types of sex glands:

–  Testes—these produce sperm and testosterone.

–  Ovaries—these produce eggs and estrogen and progesterone.

Hormones Vs. Neurotransmitters

•  Neurotransmitter—a chemical used as a neurotransmitter is released right beside that cell that it is to excite or inhibit.

•  Over time, this system developed to send rapid and specific messages.


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Hormones Vs. Neurotransmitters (cont.)

•  Hormone—when a chemical is used as a hormone it is released into the blood, which diffuses it throughout the body.

•  Over time, this system developed to send slow and widespread communication.

Main Idea

Heredity is the transmission of characteristics from parents to children. Environment is the world around you. Heredity and environment affect your body and behavior.

Vocabulary

•  heredity

•  identical twins

•  genes

•  fraternal twins

Objectives

•  Give examples of the effects of heredity and environment on behavior.

•  Summarize research on the effects of heredity and environment on behavior.


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Heredity and Environment

•  Most psychologists agree that both nature and nurture contribute to human behavior.

•  Nature refers to the characteristics that person inherits—his or her biological makeup.

Heredity and Environment (cont.)

•  Nature is also referred to as heredity, or the genetic transmission of characteristics from parents to their offspring through genes.

•  Nurture refers to environmental factors, such as family, culture, education.

DNA and Genes

•  One way to find out if a trait is inherited is to study twins.

–  Identical twins develop from a single fertilized egg (also called monozygotic) and share the same genes.

–  Fraternal twins come from two different eggs fertilized by two different sperm (also called dizygotic).

Heredity and Environment (cont.) The Nervous System The nervous system is divided into two parts: the central nervous system (CNS) and the peripheral nervous system (PNS).


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Anatomy of Two Neurons The human body contains billions of neurons. The neuron receives messages from other neurons via its dendrites. The messages are then transmitted down the axon and sent out through the axon terminals. The myelin sheath often is wrapped around the axon.

Photomicrograph of neurons

The Synapse Neurons do not touch one another. Instead, a neuron sends its messages across a gap called a synapse by releasing neurotransmitters. These neurotransmitters are received by the dendrite of another neuron.

The Parts of the Brain The brain is the largest, most complex part of the nervous system.

The Cerebral Cortex The functions of the cerebral cortex are not fully understood. Indicated here are some areas of behavioral importance.


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Functions of the Brain’s Hemispheres The idea of whether we are “right-brained” or “left-brained” has been exaggerated. We constantly use both hemispheres of our brain, since each hemisphere is specialized for processing certain kinds of information.

Brain Activity on a PET Scan A computer transforms the different levels of absorption by neurons of radioactive solution into colors. Red and yellow indicate maximum activity of neurons, while blue and green indicate minimal activity.

The Endocrine System The endocrine system, which consists of ductless glands and the hormones they produce, works closely with the nervous system in regulating body functions.

DNA and Genes The molecules of DNA make up chromosomes that contain the codes for our biological makeup.


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Roger Wolcott Sperry 1913–1994

“In other words, each hemisphere [of the brain]

seems to have its own separate and private sensations; its own

perceptions; its own concepts; and its own impulses to act. . . .

Following surgery, each hemisphere also has thereafter

its own separate chain of memories that are rendered

inaccessible to the recall processes of the other.”

Chapter Concepts Transparencies

Types of Neurotransmitters

Functions of the Somatic Nervous System

Select a transparency to view.


19 Walker_Maryann Thursday, January 6, 2011 12:16:22 PM ET

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central nervous system (CNS): the brain and spinal cord

spinal cord: nerves that run up and down the length of the back and transmit most messages between the body and the brain

peripheral nervous system (PNS): nerves branching beyond the spinal cord into the body

neurons: the long, thin cells of nerve tissue along which messages travel to and from the brain


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synapse: the gap that exists between individual nerve cells

neurotransmitters: the chemicals released by neurons, which determine the rate at which other neurons fire

somatic nervous system (SNS): the part of the peripheral nervous system that controls voluntary movement of skeletal muscles

autonomic nervous system (ANS): the part of the peripheral nervous system that controls internal biological functions


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hindbrain: a part of the brain located at the rear base of the skull that is involved in the basic processes of life

midbrain: a small part of the brain above the pons that arouses the brain, integrates sensory information, and relays it upward

forebrain: a part of the brain that covers the brain’s central core, responsible for sensory and motor control and the processing of thinking and language

lobes: the different regions into which the cerebral cortex is divided


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electroencephalograph (EEG): a machine used to record the electrical activity of large portions of the brain

computerized axial tomography (CT): an imaging technique used to study the brain to pinpoint injuries and brain deterioration

positron emission tomography (PET): an imaging technique used to see which brain areas are being activated while performing tasks

magnetic resonance imaging (MRI): a measuring technique used to study brain structure and activity


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endocrine system: a chemical communication system, using hormones, by which messages are sent through the bloodstream

hormones: chemical substances that carry messages through the body in blood

pituitary gland: the center of control of the endocrine system that secretes a large number of hormones

heredity: the genetic transmission of characteristics from parents to their offspring


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identical twins: twins who come from one fertilized egg; twins having the same heredity

genes: the basic building blocks of heredity

fraternal twins: twins who come from two different eggs fertilized by two different sperm


The Nervous System: The Basic Structure - Eastern …web.eccrsd.us/walkerm/public/Walker/Accelerated... · · 2012-11-26The Nervous System: The Basic Structure Understand that the

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