Psychology Chapter 6: Body and Behavior

1. Psychology Chapter 6:Body and Behavior

2. The Nervous System: The Basic Structure • How the nervous system works • It never rests • Controls our emotions, movements, thinking and behavior • It is divided into 2 parts (Figure 6.1) • Central Nervous System (CNS) • Consists of the brain and spinal cord • Peripheral Nervous System (PNS) • Smaller Branches of nerves that reach other parts of the body from the spinal cord (thickness of a pencil) • Take information from the organs to the CNS and from the CNS back to the organs • Each is protected by something • Brain by the skull and several layers of sheathing • Spinal cord by the vertebrae • Peripheral nerves by layers of sheathing

3. The Nervous System cont. • Neurons (Figure 6.2) Photos and video • Nerves are long, thin cells called neurons • Messages travel along these • Neurons can fire (or transmit signals) hundreds of times a minute • Neurons have three basic parts • The cell body • Contains the nucleus and produces the energy needed to fuel neuron activity • Dendrites • Short, thin fibers that stick out from the cell body and receive impulses from other neurons and send them to the cell body • Axons • Long fiber that carries the impulses away from the cell body toward the dendrites of the next neuron • Other structures • Myelin Sheath – white, fatty substance insulates and protects the axon • If it is destroyed, behavior of the person can be erratic and uncoordinated (as in MS) • Speeds the transmission of impulses • Axon terminals – branch out from the end of the axon, they are positioned directly opposite of the dendrite.

4. Neuron Diagram

5. Connection between Neurons • Neuron connection (Figure 6.3) • Synapse – the space between the axon terminals of one neuron and the dendrites of another neuron.

6. Neurons/Synapse cont. • Synapse: • This is the junction or connection between neurons • Neurons transmit impulses or messages across this space using neurotransmitters • c) Neurotransmitters – are chemicals that either excite the next neuron or stop it from transmitting • There are different types of neurotransmitters • Norepinephrine – involved in memory or learning • Endorphin – inhibits pain • Acetylocholine – involved in movement and memory (associated with paralysis and Alzheimer’s) • Dopamine – involved in learning, emotional arousal and movement (too much is associated with schizophrenia and too little with Parkinson’s) • Serotonin (an undersupply linked with a lack of norepinephrine is associated with depression)

7. Nervous System cont. • Voluntary and Involuntary Activities • Somatic Nervous System (SNS) – refers to the part of the peripheral nervous system that controls voluntary activities • Body making a response to impulses from the nerves like turning a page in a book • Autonomic Nervous System (ANS) – refers to the part of nervous system that controls involuntary activities, or those that occur automatically • Your heartbeat, breathing, stomach activity • Has two parts • Sympathetic nervous system – prepares the body for dealing with emergencies or strenuous activities • Speeds up the heart to hasten the supply of blood and nutrients to body tissues • Parasympathetic nervous system – works to conserve energy and to enhance the body’s ability to recover from strenuous activity • Reduces heart rate and blood pressure to bring the body back to its resting state

8. Nervous System Diagram Section 1 Review

9. Studying the Brain

10. Studying the Brain cont. The Brain is composed of 3 parts • The Hindbrain • Located at the rear base of the skull • Involved in the most basic processes of life • Includes: • The cerebellum • The medulla • The pons

11. Studying the Brain cont. 2. The Midbrain • Integrates sensory information • Alerts the rest of the brain to incoming signals and is involved in the sleep/wake cycle

12. Studying the Brain Cont… 3. The Forebrain • All information from the senses, minus smell, come through the thalamus • Controls: hunger, thirst, sexual behavior, reaction to temperature • Higher level thinking processes • Ability to learn and store complex and abstract information; project thinking into the future • See, read and understand • Regulates emotions and motivations • Includes: • Thalamus • Cerebral Cortex • Cerebrum • Limbric System • Hypothalamus, amygdala (violent emotions and fear), thalamus and hippocampus (memory)

13. Studying the Brain cont. Lobes of the Brain • Cerebrum is split into 2 sides or hemispheres • Connected by the corpus callosum

14. Studying the Brain cont. • 2. Occipital Lobe • Where visual signals are processed • Damage may cause visual impairment • 3. Parietal Lobe • Receives and deals with information from all the senses • 4. Temporal Lobe • Concerns: hearing, memory, emotion and thinking • 5. Frontal Lobe • Concerned with organization, planning and creative thinking • 6. Somatosensory Cortex • Receives information from the touch sensors • 7. Motor Cortex • Sends information to control body movement

15. Studying the Brain cont. The Hemispheres • Each work together to compliment and help each other • Corpus callosum carries information back and forth between the hemispheres and the lobes (each of the 4 lobes are present in both hemispheres) • 3. Left Hemisphere • Controls movement on the right side of the body • Where speech is located (in most people) • Specialized for mathematical ability, calculation and logic • 4. Right Hemisphere • Controls the left side of the body • Adept at visual and spatial relations • Perceptual tasks • Recognizing patterns (music and art) • Creativity and intuition

16. Studying the Brain cont. Split Brain Operations • Usually done to those with severe seizures • 2. Cuts the corpus callosum • Lowers the severity and number of seizures • Information cannot cross into other spheres • Person with a split brain can hold a ball in their right hand and say it was a ball, but not holding it in their left hand. • Shows how unique and the specialize functions and skills of each hemisphere • Remained practically unchanged in intelligence, emotion and personality

17. Studying the Brain cont. How do Psychologists study the brain? • 1. Recording • Putting electrodes into the brain to record electrical activity • EEG – electroencephalograph. Millions and millions of neurons can be studied at one time with an EEG attached to the scalp • Shows brain waves which show the amount of neural activity • 2. Stimulation • Fires off neurons by electricity • Can show what areas of the brain do • Memories • Songs • Smells • 3. Lesions • Cutting or destroying areas of healthy brain tissue and studying the results • 4. Accidents • Studying the results of accidents and medical issues • Phineas Gage • Coma patients • Traumatic head injuries

18. Studying the Brain cont. • 5. Images • CAT (Computerized Axial Tomography) scans • Transfers the amount of radiation absorbed by the density of brain tissue into a 3 dimensional view of the brain • PET (Positron Emission Tomography) scans • Shows the absence or presence state of activity in an area of the brain through radioactive dye • MRI (Magnetic Resonance Imaging) • Ability to study both activity and brain structure • Uses both CAT and PET scanning capabilities • fMRI (Functional Magnetic Resonance Imaging) • New, can see the blow flow into active areas to determine activity and functionality Section 2 Review

19. The Endocrine System Endocrine system – sends chemical messages to and from the brain • 1. Chemical messages used to send are called hormones • Produced by the glands and send by blood and other bodily fluids • Once in the blood stream, they can only be received by the specific organs that they can influence • Ductless, they don’t need pores or ducts (small holes) to release to an organ (sweat glands, tear glands, salivary glands) • Various effects on behavior and moods • Growth of organs, muscles and bones • 2. Pituitary Gland • Directed by the hypothalamus • Secretes a large number of hormones, many of which control the output of other hormones • Corrects imbalances of hormones in the body • Keeps metabolism in check despite outside influences • Control growth and reproduction

20. The Endocrine System cont. • 3. Thyroid Gland • Produces thyroxine • Stimulates chemical reactions for all tissues • Too little, people feel lazy; too much people lose weight, sleep too much and are overactive • 4. Adrenal Gland • Become active when someone is angry or frightened • Release Epinephrine (adrenaline) and norepinephrine (nor adrenaline) • Speed up heart rate and breathing; heighten emotion; extra energy • Secret cortical steroids • Help muscle develop and cause the liver to release stored sugar for extra energy in emergencies

21. The Endocrine System cont. • 5. Sex Glands • 2 Types • Testes – male • Produce sperm and testosterone (sex hormone) • Ovaries – females • Produce eggs and estrogen and progesterone • Testosterone • Important to physical development of males during the prenatal and adolescence periods • Prenatal – helps decide the sex of the fetus • Adolescence – development of bone and muscle, male sex characteristics • Estrogen and progesterone • Development of the female sex characteristics • Regulate the reproductive cycle • Variances of the hormones cause the symptoms of PMS • 6. Hormones vs. Neurotransmitters Difference • When the chemical is released right beside a cell to excite or inhibit it, it is a neurotransmitter • When a chemical is released into the blood, it is a hormone Section 3 Review

22. Heredity and the Environment • 1. Is human behavior instinctive (due to heredity) or learned (environment) • Heredity is the genetic transmission of characteristics from parents to their offspring • 2. Nature vs. Nuture • a. Genes and behavior • Reproduced and passed onto children • Occur through their role in building and modifying the physical structures of the body • b. Twin studies • Identical twins – develop from the same single, fertilized egg, thus sharing the same genes • Fraternal twins – develop from 2 fertilized eggs, not more similar genes than brothers or sisters • One study showed that twins growing up apart from one another showed similar behaviors, despite different socials, cultural and economic backgrounds • Suggests heredity may contribute to behaviors once thought more environment in nature • It is possible though to alter the environment that genes operate in thus changes these “hereditary” ideas

23. Heredity and the Environment • Section 4 Review • Chapter 6 Study Guide • Chapter 6 Review Quiz • Chapter 6 Test