Chapter 3 BIOLOGY AND BEHAVIOR

1. Chapter 3BIOLOGY AND BEHAVIOR Section 1:The Nervous System Section 2: The Brain: Our Control Center Section 3: The Endocrine System Section 4: Heredity: Our Genetic Background

2. Chapter 3:Section 1 The Nervous System Chapter 3

3. Main Objective: • Explain how messages are transmitted by neurons and describe the functions of the peripheral nervous system. Chapter 3

4. What does the Nervous System do??? • Thinking • Feeling • Moving • Dreaming • Regulates internal functions • Learning/memory • Etc…. Chapter 3

5. Consists of 2 main parts: • Central Nervous System: • Brain and spinal cord 2. Peripheral Nervous System: * made up of nerve cells that send messages between the central nervous system and all the parts of the body. Chapter 3

6. Neurons: • Neurons: • A nerve cell; the basic building block of the nervous system. • Each of us has more than 100 billionneurons!!! Chapter 3

7. Components of a Neuron: • Cell Body: Produces energy that fuels the activity of the cell. • Dendrites: Receive information from other neurons and pass the message through the cell body • Axon: Carries messages away. Chapter 3

8. Components of Neuron (cont’d) • Myelin sheath: • A white, fatty substance that insulates axons and enables rapid transmission of neural impulses. • Axon terminals: • Small fibers branching out from an axon. Chapter 3

9. The Communication Process: • Messages are sent from the axon terminals of one neuron to the dendrites of other neurons. • In order for a message to be sent from one neuron to another neuron, it must cross the synapse • A junction between the axon terminals of one neuron and the dendrites of another neuron. • Less than a millionth of an inch wide! Chapter 3

10. Anatomy of 2 Neurons: Chapter 3

11. Communication (cont’d) • Messages are received by the dendrites and travel through the cell body and the axon to the axon terminals. • They cross synapses to the dendrites of other neurons • Newsynapses can develop between neurons that were not previously connected, as when we learn something new!! Chapter 3

12. Neurotransmitters: Chemical Messengers • Neurons send messages across synapses through the release of neurotransmitters. • Chemicals that are stored in sacs in the axon terminals. • 100’s can be fired every second!! Chapter 3

13. Neurotransmitters (cont’d) • The message is converted into an electrical impulse that travels the length of the neuron. • The message is then transmitted to the next neuron by neurotransmitters • This whole process takes only a fraction of a second!!! Chapter 3

14. Different Types of Neurotransmitters! • Acetylcholine (Ach): control of muscles. • Plays a part in Alzheimer’s disease • Dopamine: motor behavior • Deficiency plays a role in Parkinson's disease • Serotonin: emotional arousal and sleep Chapter 3

15. OVERVIEW OF MESSAGE TRANSMISSION VIA NEURONS Section 1: The Nervous System • Messages are sent from the axon terminals of one neuron to the dendrites of other neurons • Messages travel in one direction and are received by the dendrites and travel through the cell body and the axon to the axon terminals. • From there messages cross synapses to the dendrites of other neurons. Chapter 3

16. Hmmm…What do you think??? Endorphins are neurotransmitters that NATURALLY reduce pain and boost mood. Flooding the brain with painkillers, antidepressants, or other drugs may cause the brain to stop producing endorphins. Thus, when such a drug is discontinued, a person may experience a period of discomfort—ranging from mild to agonizing– until the brain resumes production of endorphins. What do you think about antidepressants? Do the benefits outweigh the potential harm? Chapter 3

17. The Central Nervous System: Consists of brain and spinal cord Chapter 3

18. Central Nervous System (cont’d) • Spinal cord: • A column of nerves within the spine that transmit messages to and from the brain. • Protected by the spine. • Spinal reflex: simple, automatic response to something. • EX: Remove hand for hot stove! Chapter 3

19. Other simple Reflexes: • Blink when dust in your eye • Sneeze with pepper • Tapping on knee to see if kick • Knee-jerk reflex • Want to try?…sit on desk with legs crossed. The “doctor” needs to gently strike the knee with a “karate chop”. Does the knee jerk? Chapter 3

20. THE PERIPHERAL NERVOUS SYSTEM Section 1: The Nervous System • Responsible for transmitting messages between the central nervous system and all part of the body and is made up of the somatic and autonomic nervous system Chapter 3

21. The somatic nervous system transmits sensory messages to the central nervous system. • Activated by touch, pain, changes in temperature, and changes in body position. • Enables us to experience: • Hot/cold; pain/pressure; helps us maintain posture/balance. Chapter 3

22. The autonomic nervous system regulates the body’s vital functions such as heartbeat and breathing. • 2 divisions: • Sympathetic • Parasympathetic Chapter 3

23. Sympathetic System: • Activated when a person is going into action, perhaps because of some stressful event. • “Fight-or-Flight” • Prepares you to confront situation or to run away! • May suppress digestion, increase heart & respiration rates, and elevate blood pressure. Chapter 3

24. Parasympathetic Nervous System: • Restores body’s reserves of energy after an action has occurred. • EX: Heart rate and blood pressure are normalized, breathing is slowed, and digestion returns to normal. Chapter 3

25. Chapter 3: Section 2 The Brain: Our Control Center Chapter 3

26. Main Objective: • Identify the major structures of the brain, and explain the functions of each structure. Chapter 3

27. Brain Divided into 3 Sections: • Hindbrain • Midbrain • Forebrain Chapter 3

28. Hindbrain: • Medulla: • Vital functions such as heart rate, blood pressure, and breathing. • Pons: • Located in front of medulla and is involved in regulating body movement, attention, sleep, and alertness. • Cerebellum: • Balance and coordination. Chapter 3

29. The Midbrain: • Located between hindbrain and forebrain. • Vision and hearing • Contains part of reticular activating system: • Part of brain that is involved in attention, sleep, and arousal. • EX: Drugs/alcohol can affect this alertness. Chapter 3

30. The Forebrain: Involved in complex thinking processes!! • 4 key areas: • Thalamus • Hypothalamus • Limbic System • Cerebrum Chapter 3

31. Thalamus: • The structure of the brain that relays messages from the sense organs to the cerebral cortex. • EX: Relays message to brain, such as pain, in order for brain to respond. Chapter 3

32. Hypothalamus: • The neural structure located below the thalamus that controls temperature, hunger, thirst, and various aspects of emotion: • Sexual behavior; caring for offspring, aggression; etc…. Chapter 3

33. Limbic System: • A group of neural structures at the base of the cerebral hemispheres that is associated with emotion, motivation, hunger, sex, and aggression. Chapter 3

34. Cerebrum: • The large mass of the forebrain, consisting of two hemispheres. • Cerebral Cortex: • The bumpy, convoluted surface of the brain; the body’s control and information-processing center. Chapter 3

35. The Cerebral Cortex: What Makes Us Unique • Made up of right and left hemispheres. • Corpus callosum: • The nerve fibers that connect the left and right hemispheres of the cerebral cortex. Chapter 3

36. Information received by one side of the body is transmitted to the OPPOSITE hemisphere of the brain. • Each hemisphere of the brain is divided into four parts/lobes. Chapter 3

37. Complete the following on the SAME handout! • Occipital Lobe: • Vision Chapter 3

38. Temporal Lobe: • Hearing/Auditory Chapter 3

39. Parietal Lobe: • Sensory Cortex: • Warmth, cold ,touch ,and pain Chapter 3

40. Frontal Lobe: • Motor cortex • Neurons in the motor cortex fire when we move certain parts of our body. Chapter 3

41. Association Areas: • Association areas: • Areas of the cerebral cortex that are involved in such mental operations as thinking, memory, learning, and problem solving. • Shape information into something meaningful. • EX: Puzzle Chapter 3

42. Language Abilities: Right-handed people: Language functions based in lefthemisphere About 2 out of 3 left-handed people: Language in left hemisphere Chapter 3

43. 2 Key Language Areas: • Broca’s Area: • Located in frontallobe. • Controls area of face used for speaking. • If damaged, then person speaks slowly, using simple sentences! • Wernicke’s Area: • Located in temporal lobe • Pieces together sounds and sights • If damaged, then speech becomes meaningless!! • EX: “Stealing cookies”…pg. 63 Chapter 3

44. Left vs. Right Hemispheres: • Left Hemisphere: • Language, logic, problem solving, mathematical computation. • Right Hemisphere: • Imagination, art, feelings, and spatial relations. Even though have heard “right brained” and “left brained” the hemispheres DO NOT act independently of each other!! Chapter 3

45. Midsaggital Plane: Chapter 3

46. Turn to Pg. 65 Is Phineas Gage Still the Same Man??? Chapter 3

47. Methods of Studying the Brain: • Accidents: • Accidents and brain damage • Electrical Stimulation of the Brain: Stimulate parts of brain to change behavioral patterns. Chapter 3

48. The Electroencephalogram (EEG): • Electrodes record electrical activity of brain. • Used to diagnose some psychological disorders and locate tumors. Chapter 3

49. Scans: • CAT scan : Computerized axial tomography • 3-dimensionanl view of brain. • MRI: Magnetic resonance imaging • More powerful; shows details more clearly • PET scan: Positron emission tomography • Show activity of brain at given time Chapter 3

50. Chapter 3: Section 3 The Endocrine System Chapter 3