How is the Nervous System Organized?

1. How is the Nervous System Organized? Chapter 3 Neuroscience

2. Module Objectives • What is the Nervous System? • What are the 3 divisions of the brain? • Hind-brain • Mid-brain • Forebrain • Discuss how these structures influence behavior

3. Have you heard the expression “Information is power?” Nowhere is this truer than in the human body. Without information, we could not survive. Neurons within our nervous system must take in sensory information from the outside world and then decide what to do with the information.

4. What is the Nervous System? • The Nervous System is the body’s main processing system for information. • This consists of structures and organs that facilitate electrical and chemical communication in the body.

5. The Nervous System • Central Nervous System (CNS) • The brain • The spinal cord • Peripheral Nervous System (PNS) • The main function of the PNS is to connect the CNS to the limbs and organs

6. CNS-Spinal Cord • The spinal cord transmits signals from the sensory organs, muscles and glands to the brain. • Controls reflexive responses • Conveys signals from the rest of the body

7. The spinal cord is like a communication superhighway between the brain and the rest of the body.

8. Spinal cord communication • Communicates with the body below the head through sensory and motor neurons • Sensory neurons (afferent neurons) • Carry information about touch, pain, and other senses from the periphery of the body to the spinal cord • Motor neurons (efferent neurons) • Transmit impulses from the central nervous system to the muscles and glands

9. Did you know…? • There are about 3 million miles of axons in the human brain • Information travels in the nerves at speeds up to 268 miles per hour!

10. How much do you know about YOUR brain?? Structures of the brain

11. What observations can you make about the brain?

12. Looking at the Brain • The exterior covering (cortex) of the brain is wrinkled which increases the surface area of the brain • The brain is divided into 2 hemispheres • Right and left hemispheres

13. The hemispheres of the brain are connected • The Corpus Callosum connects these hemispheres and allows communication from one side of the brain to the other.

14. Corpus Callosum

15. Damage to the Corpus Callosum results in two independent brains in one skull • Split brain patients allowed researchers to discover “hemispheric specialization”

17. What does a spilt-brain patient look like?Review the following video and make some observations

19. Split Brain Research • This research showed that each hemisphere of the brain is specialized • The right brain is associated with musical ability, spatial and drawing tasks • The left brain is associated with speech and language.

20. Left Brain Controls Right Side of Body Right Side Visual Field Speaking Reading Logical Thinking Analytical Skills Sequential Processing Right Brain Controls Left Side of Body Left Side Visual Field Spatial Processing Facial Recognition Music Emotional Expression Holistic Thinking Hemispheric Specialization

21. Want to play the Split Brain game? http://nobelprize.org/educational_games/medicine/split-brain/about.html

22. Take the Wagner Preference Inventory now! This quiz will help determine which side of your brain is most dominant. It can be found in the Module 2 notes folder.

23. How are these brains different?

24. Why are they different? • More recently evolved animals have a larger proportion of the brain taken up by the cerebral cortex. • The cerebral cortex, made up of four lobes, is involved in many complex brain functions including: • memory • perceptual awareness • "thinking” • language and consciousness

25. Does bigger mean smarter? NO… larger brains have nothing to do with intelligence.

26. Did you know… • The brain of Albert Einstein weighed 1,230 grams. This is far below the average brain weight of 1,400 grams • The brain of an elephant weighs about 4.78 kg (10.5 lb). An adult human brain weighs about 1.4 kg (3 lb) • The heaviest human brain ever recorded weighed 5 lbs., 1.1 oz (The Guinness Book of World Records, 1997). • The total surface area of the cerebral cortex is about 2500 sq. cm (~2.5 sq. ft). • It is estimated that there are 60 trillion synapses in the cerebral cortex.

27. Three Divisions of the Brain • Hindbrain • Midbrain • Forebrain

28. The Hindbrain • This is the most primitive division of the brain. • The structures in the lower brain tend to be responsible for basic, reflexive functions. • Includes the cerebellum, Pons, and medulla

29. The Hindbrain • The Medulla is the most primitive and lowest portion of the hindbrain (Part of the brain stem). • It controls basic body functions- heart beat, digestion and breathing.

31. Pons- provides link (“bridge”)between the medulla and the cerebellum and rest of brain is involved in respiration, movement, sleeping, waking, and dreaming. Cerebellum- “Little brain” – attached to back surface of brain stem. Influences balance, coordination and movement Allows you to walk a straight line

33. Where do complex thought and behavior come from?

34. True or False?We Only Use 10% of Our Brain

35. True or False?We Only Use 10% of Our BrainFalse! This is a Psychology Myth…we use all of brain most of the time.

36. Have you ever seen a Kung-Fu movie? What is most obvious about a movie that has been dubbed into English?

38. The language doesn’t match, right? • Imagine if you had to go through life inside a Kung-fu movie? If your midbrain was damaged it would effect your ability to process auditory information.

39. The Midbrain • The midbrain helps us orient our eye and body movements to visual and auditory stimuli • Coordination of visual and auditory reflexes • The reticular formation (RF) runs through the hindbrain and midbrain. • This finger-shaped structure filters incoming sensory information and alerts the higher brain centers to important events.

40. The Forebrain • This the largest, most complicated and most advanced brain division. • This area of the brain is associated with complex thought and behaviors: • The ability to concentrate, elaboration of thought, judgment and inhibition.

41. Forebrain • The Thalamusis a large structure of forebrain that acts a routing station or air-traffic controller. • Processes sensory information from the CNS before it reaches the cerebral cortex

42. The Hypothalamusis a pea-sized structure that controls many complex behaviors such as eating, drinking and sexual activity.

43. This small structure regulates a variety of complex behaviors. If you have trouble remembering what this structure does try this… The FOUR F’s…

44. Food

45. Fight

46. Flight

47. And…Ummm….(Fornication?)

48. Where do my emotions come from? • The limbic system is an interconnected group of structures that are especially significant in emotions, memory, and social behavior. • This is referred to as the “pleasure center” of the brain • The limbic system also includes the hippocampus and amygdala

49. The Limbic System Amygdala

50. Can pleasure take us over? • YES! Research has shown that rats who received electrical stimulation will repeatedly press a lever which activates this region-producing pleasure (Olds & Milner, 1954). • The rats will choose to press the bar in preference over food and water, eventually dying from exhaustion!