Chapter 6: Body and Behavior

Section 1 – The Nervous System: The Basic Structure

  1. How the nervous system works
  2. It is never at rest
  3. Controls our emotions, movements, thinking and behavior
  4. It is divided into 2 parts (Figure 6.1)
  5. Central Nervous System (CNS)
  6. Consists of the brain and spinal cord
  7. Peripheral Nervous System (PNS)
  8. Smaller Branches of nerves that reach other parts of the body from the spinal cord (thickness of a pencil)
  9. Take information from the organs to the CNS and from the CNS back to the organs
  10. Each is protected by something
  11. Brain by the skull and several layers of sheathing
  12. Spinal cord by the vertebrae
  13. Peripheral nerves by layers of sheathing
  14. Neurons (Figure 6.2)
  15. Nerves are long, thin cells called neurons
  16. Messages travel along these
  17. Neurons can fire (or transmit signals) hundreds of times a minute
  18. Neurons have three basic parts
  19. The cell body
  20. Contains the nucleus and produces the energy needed to fuel neuron activity
  21. Dendrites
  22. Short, thin fibers that stick out from the cell body and receive impulses from other neurons and send them to the cell body
  23. Axons
  24. Long fiber that carries the impulses away from the cell body toward the dendrites of the next neuron
  25. Other structures
  26. Myelin Sheath – white, fatty substance insulates and protects the axon
  27. If it is destroyed, behavior of the person can be erratic and uncoordinated (as in MS)
  28. Speeds the transmission of impulses
  29. Axon terminals – branch out from the end of the axon, they are positioned directly opposite of the dendrite.

  1. Neuron connection (Figure 6.3)
  2. Synapse – the space between the axon terminals of one neuron and the dendrites of another neuron.

  1. This is the junction or connection between neurons
  2. Neurons transmit impulses or messages across this space using neurotransmitters
  3. Neurotransmitters – are chemicals that either excite the next neuron or stop it from transmitting
  4. There are different types of neurotransmitters
  5. Norepinephrine – involved in memory or learning
  6. Endorphin – inhibits pain
  7. Acetylocholine – involved in movement and memory (associated with paralysis and Alzheimer’s)
  8. Dopamine – involved in learning, emotional arousal and movement (too much is associated with schizophrenia and too little with Parkinson’s)
  9. Serotonin (an undersupply linked with a lack of norepinephrine is associated with depression)
  1. Voluntary and Involuntary Activities
  2. Somatic Nervous System (SNS) – refers to the part of the peripheral nervous system that controls voluntary activities
  3. Body making a response to impulses from the nerves like turning a page in a book
  4. Autonomic Nervous System (ANS) – refers to the part of nervous system that controls involuntary activities, or those that occur automatically
  5. Your heartbeat, breathing, stomach activity
  6. Has two parts
  7. Sympathetic nervous system – prepares the body for dealing with emergencies or strenuous activities
  8. Speeds up the heart to hasten the supply of blood and nutrients to body tissues
  9. Parasympathetic nervous system – works to conserve energy and to enhance the body’s ability to recover from strenuous activity
  10. Reduces heart rate and blood pressure to bring the body back to its resting state

Section 2 – Studying the Brain

  1. The brain is composed of three parts
  2. The Hindbrain

  1. Located at the rear base of the skull
  2. Involved in the most basic processes of life
  3. Includes:
  4. The cerebellum
  5. The medulla
  6. The pons
  1. The Midbrain
  2. Integrates sensory information
  3. Alerts the rest of the brain to incoming signals and is involved in the sleep/wake cycle
  1. The Forebrain

  1. All information from the senses, minus smell, come through the thalamus
  2. Controls: hunger, thirst, sexual behavior, reaction to temperature
  3. Higher level thinking processes
  4. Ability to learn and store complex and abstract information; project thinking into the future
  5. See, read and understand
  6. Regulates emotions and motivations
  7. Includes:
  8. Thalamus
  9. Cerebral Cortex
  10. Cerebrum
  11. Limbric System
  12. Hypothalamus, amygdala (violent emotions and fear), thalamus and hippocampus (memory)
  1. Lobes of the brain
  2. Cerebrum is split into 2 sides or hemispheres
  3. Connected by the corpus callosum
  1. Occipital Lobe
  2. Where visual signals are processed
  3. Damage may cause visual impairment
  4. Parietal Lobe
  5. Receives and deals with information from all the senses
  6. Temporal Lobe
  7. Concerns: hearing, memory, emotion and thinking
  8. Frontal Lobe
  9. Concerned with organization, planning and creative thinking
  10. Somatosensory Cortex
  11. Receives information from the touch sensors
  12. Motor Cortex
  13. Sends information to control body movement
  14. All these areas work together

C.The Hemispheres

  1. Each work together to compliment and help each other
  2. 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
  4. Controls movement on the right side of the body
  5. Where speech is located (in most people)
  6. Specialized for mathematical ability, calculation and logic
  7. Right Hemisphere
  8. Controls the left side of the body
  9. Adept at visual and spatial relations
  10. Perceptual tasks
  11. Recognizing patterns (music and art)
  12. Creativity and intuition
  1. Split Brain Operations
  2. Usually done to those with severe seizures
  3. Cuts the corpus callosum
  4. Lowers the severity and number of seizures
  5. Information cannot cross into other spheres
  6. 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
  7. Shows how unique and the specialize functions and skills of each hemisphere
  8. Remained practically unchanged in intelligence, emotion and personality

E.How Psychologists study the brain

  1. Recording
  2. Putting electrodes into the brain to record electrical activity
  3. EEG – electroencephalograph. Millions and millions of neurons can be studied at one time with an EEG attached to the scalp
  4. Shows brain waves which show the amount of neural activity
  5. Stimulation
  6. Fires off neurons by electricity
  7. Can show what areas of the brain do
  8. Memories
  9. Songs
  10. Smells
  11. Lesions
  12. Cutting or destroying areas of healthy brain tissue and studying the results
  13. Accidents
  14. Studying the results of accidents and medical issues
  15. Phineas Gage
  16. Coma patients
  17. Traumatic head injuries
  18. Images
  19. CAT (Computerized Axial Tomography) scans
  20. Transfers the amount of radiation absorbed by the density of brain tissue into a 3 dimensional view of the brain
  21. PET (Positron Emission Tomography) scans
  22. Shows the absence or presence state of activity in an area of the brain through radioactive dye
  23. MRI (Magnetic Resonance Imaging)
  24. Ability to study both activity and brain structure
  25. Uses both CAT and PET scanning capabilities
  26. fMRI (Functional Magnetic Resonance Imaging)
  27. New, can see the blow flow into active areas to determine activity and functionality

Section 3 – The Endocrine System

  1. Endocrine system – sends chemical messages to and from the brain
  2. Chemical messages used to send are called hormones
  3. Produced by the glands and send by blood and other bodily fluids
  4. Once in the blood stream, they can only be received by the specific organs that they can influence
  5. Ductless, they don’t need pores or ducts (small holes) to release to an organ (sweat glands, tear glands, salivary glands)
  6. Various effects on behavior and moods
  7. Growth of organs, muscles and bones
  8. Pituitary Gland
  9. Directed by the hypothalamus
  10. Secretes a large number of hormones, many of which control the output of other hormones
  11. Corrects imbalances of hormones in the body
  12. Keeps metabolism in check despite outside influences
  13. Control growth and reproduction
  14. Thyroid Gland
  15. Produces thyroxine
  16. Stimulates chemical reactions for all tissues
  17. Too little, people feel lazy; too much people lose weight, sleep too much and are overactive
  18. Adrenal Gland
  19. Become active when someone is angry or frightened
  20. Release Epinephrine (adrenaline) and norepinephrine (nor adrenaline)
  21. Speed up heart rate and breathing; heighten emotion; extra energy
  22. Secret cortical steroids
  23. Help muscle develop and cause the liver to release stored sugar for extra energy in emergencies
  24. Sex Glands
  25. 2 Types
  26. Testes – male
  27. Produce sperm and testosterone (sex hormone)
  28. Ovaries – females
  29. Produce eggs and estrogen and progesterone
  30. Testosterone
  31. Important to physical development of males during the prenatal and adolescence periods
  32. Prenatal – helps decide the sex of the fetus
  33. Adolescence – development of bone and muscle, male sex characteristics
  34. Estrogen and progesterone
  35. Development of the female sex characteristics
  36. Regulate the reproductive cycle
  37. Variances of the hormones cause the symptoms of PMS
  38. Hormones vs. Neurotransmitters
  39. Difference
  40. When the chemical is released right beside a cell to excite or inhibit it, it is a neurotransmitter
  41. When a chemical is released into the blood, it is a hormone

Section 4 – Heredity and Environment

  1. Is human behavior instinctive (due to heredity) or learned (environment)
  2. Heredity is the genetic transmission of characteristics from parents to their offspring
  3. Are people born a certain way or did they learn it?
  4. Nature vs. Nurture
  5. Genes and behavior
  6. Reproduced and passed onto children
  7. Occur through their role in building and modifying the physical structures of the body
  8. Twin studies
  9. Identical twins – develop from the same single, fertilized egg, thus sharing the same genes
  10. Fraternal twins – develop from 2 fertilized eggs, not more similar genes than brothers or sisters
  11. One study showed that twins growing up apart from one another showed similar behaviors, despite different socials, cultural and economic backgrounds
  12. Suggests heredity may contribute to behaviors once thought more environment in nature
  13. It is possible though to alter the environment that genes operate in thus changes these “hereditary” ideas