Chapter Objectives Section 1

Transcription

1 Chapter Introduction Section 1: The Nervous System: The Basic Structure Section 2: Studying the Brain Section 3: Section 4: The Endocrine System 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. Heredity and Environment Chapter Objectives Section 2 Chapter Objectives Section 3 Studying the Brain The Endocrine System Discuss the many parts of the brain that work together to coordinate movement and stimulate thinking and emotions. Explain how the endocrine system controls and excites growth and affects emotions and behavior. 1

2 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) 2

3 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). How the Nervous System Works (cont.) 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. The Nervous System Anatomy of Two Neurons 3

4 How the Nervous System Works (cont.) Neurons have four basic parts: Dendrites Cell body An axon Axon terminals How the Nervous System Works (cont.) 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 How the Nervous System Works (cont.) 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. How the Nervous System Works (cont.) There are many different neurotransmitters including: Norepinephrine Endorphin Acetylcholine Dopamine Serotonin 4

5 How the Nervous System Works (cont.) 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. How the Nervous System Works (cont.) 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. How the Nervous System Works (cont.) 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. How the Nervous System Works (cont.) The ANS has two parts: The sympathetic nervous system The parasympathetic nervous system 5

6 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! A. A B. B C. C D. D 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) positron emission tomography (PET) magnetic resonance imaging (MRI) computerized axial tomography (CT) 6

7 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 7

8 FOREBRAIN The Cerebral Cortex 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 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 8

9 The Three Brains (cont.) 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 Three Brains (cont.) The right side controls: Visual and spatial relations Perceptual tasks Recognition of patterns Creativity and intuition Functions of the Brain s Hemispheres Functions of the Brain s Hemispheres The Three Brains (cont.) The left side controls: Speech Mathematical ability Calculation Logic The Three Brains (cont.) 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. Functions of the Brain s Hemispheres Roger Wolcott Sperry 9

10 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 A. A b) Medulla breathing, heart rate, some reflexes B. B C. C 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. 10

11 How Psychologists Study the Brain How Psychologists Study the Brain The methods used to explore the brain include: Imaging is also used to study the brain: (cont.) Recording with an electroencephalograph (EEG) Stimulation (cont.) Computerized axial tomography (CT) Positron emission tomography (PET) Magnetic resonance imaging (MRI) Lesioning Accidents Brain Activity on a PET Scan Main Idea Vocabulary The endocrine system controls and excites growth and affects emotions and behavior in people. endocrine system hormones pituitary gland 11

12 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 Endocrine Glands (cont.) 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. 12

13 The Endocrine Glands (cont.) 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 Endocrine Glands (cont.) 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. The Endocrine Glands (cont.) 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. 13

14 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. 14

15 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 Heredity and Environment (cont.) 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). The Nervous System The nervous system is divided into two parts: the central nervous system (CNS) and the peripheral nervous system (PNS). 15

16 Anatomy of Two Neurons The Synapse 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. 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. Photomicrograph of neurons The Parts of the Brain The Cerebral Cortex The brain is the largest, most complex part of the nervous system. The functions of the cerebral cortex are not fully understood. Indicated here are some areas of behavioral importance. 16

17 Functions of the Brain s Hemispheres Brain Activity on a PET Scan 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. 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 DNA and Genes The endocrine system, which consists of ductless glands and the hormones they produce, works closely with the nervous system in regulating body functions. The molecules of DNA make up chromosomes that contain the codes for our biological makeup. 17

18 Chapter Concepts Transparencies Roger Wolcott Sperry 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. Types of Neurotransmitters Functions of the Somatic Nervous System Select a transparency to view. 18

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20 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 20

21 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 21

22 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 22

23 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 23

24 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 24

25 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 25