1. PowerPoint ® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings PART B 7 The Nervous System

2. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc  Reflex—rapid, predictable, and involuntary response to a stimulus  Occurs over pathways called reflex arcs  Reflex arc—direct route from a sensory neuron, to an interneuron, to an effector

3. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Effector Sensory neuron Motor neuron Integration center (a)

4. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 1 Stimulus at distal end of neuron Skin Receptor (a)

5. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 2 Stimulus at distal end of neuron Skin Receptor Sensory neuron (a)

6. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 3 Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Sensory neuron Integration center (a)

7. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 4 Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Sensory neuron Motor neuron Integration center (a)

8. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Reflex Arc Figure 7.11a, step 5 Stimulus at distal end of neuron Skin Spinal cord (in cross section) Interneuron Receptor Effector Sensory neuron Motor neuron Integration center (a)

9. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b–c Spinal cord Sensory (afferent) neuron Inter- neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) Effector (quadriceps muscle of thigh) Effector (biceps brachii muscle) Synapse in ventral horn gray matter (c) (b)

10. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 1 Spinal cord Sensory receptors (stretch receptors in the quadriceps muscle) (b)

11. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 2 Spinal cord Sensory (afferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) (b)

12. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 3 Spinal cord Sensory (afferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Synapse in ventral horn gray matter (b)

13. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 4 Spinal cord Sensory (afferent) neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Synapse in ventral horn gray matter (b)

14. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b, step 5 Spinal cord Sensory (afferent) neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Effector (quadriceps muscle of thigh) Synapse in ventral horn gray matter (b)

15. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 1 Spinal cord Sensory receptors (pain receptors in the skin) (c)

16. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 2 Spinal cord Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) (c)

17. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 3 Spinal cord Inter- neuron Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) (c)

18. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 4a Spinal cord Inter- neuron Motor (efferent) neuron Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) (c)

19. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11c, step 4b Spinal cord Inter- neuron Motor (efferent) neuron Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) Effector (biceps brachii muscle) (c)

20. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Simple Reflex Arc Figure 7.11b–c Spinal cord Sensory (afferent) neuron Inter- neuron Motor (efferent) neuron Sensory receptors (stretch receptors in the quadriceps muscle) Sensory (afferent) neuron Sensory receptors (pain receptors in the skin) Effector (quadriceps muscle of thigh) Effector (biceps brachii muscle) Synapse in ventral horn gray matter (c) (b)

21. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of Reflexes and Regulation  Somatic reflexes  Activation of skeletal muscles  Example : When you move your hand away from a hot stove

22. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of Reflexes and Regulation  Autonomic reflexes  Smooth muscle regulation  Heart and blood pressure regulation  Regulation of glands  Digestive system regulation

23. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Types of Reflexes and Regulation  Patellar, or knee-jerk, reflex is an example of a two-neuron reflex arc Figure 7.11d

24. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Central Nervous System (CNS)  CNS develops from the embryonic neural tube  The neural tube becomes the brain and spinal cord  The opening of the neural tube becomes the ventricles  Four chambers within the brain  Filled with cerebrospinal fluid

25. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Central Nervous System (CNS) Figure 7.12a

26. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain  Cerebral hemispheres (cerebrum)  Diencephalon  Brain stem  Cerebellum

27. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.12b

28. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Cerebral Hemispheres (Cerebrum)  Paired (left and right) superior parts of the brain  Includes more than half of the brain mass  The surface is made of ridges (gyri) and grooves (sulci)

29. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13a

30. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Lobes of the cerebrum  Fissures (deep grooves) divide the cerebrum into lobes  Surface lobes of the cerebrum  Frontal lobe  Parietal lobe  Occipital lobe  Temporal lobe

31. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13b

32. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Specialized areas of the cerebrum  Primary somatic sensory area  Receives impulses from the body’s sensory receptors  Located in parietal lobe  Primary motor area  Sends impulses to skeletal muscles  Located in frontal lobe  Broca’s area  Involved in our ability to speak

33. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13c

34. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.14

35. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Cerebral areas involved in special senses  Gustatory area (taste)  Visual area  Auditory area  Olfactory area

36. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Interpretation areas of the cerebrum  Speech/language region  Language comprehension region  General interpretation area

37. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13c

38. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Layers of the cerebrum  Gray matter—outer layer in the cerebral cortex composed mostly of neuron cell bodies  White matter—fiber tracts deep to the gray matter  Corpus callosum connects hemispheres  Basal nuclei—islands of gray matter buried within the white matter

39. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.15

40. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16

41. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Sits on top of the brain stem  Enclosed by the cerebral hemispheres  Made of three parts  Thalamus  Hypothalamus  Epithalamus

42. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.12b

43. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16a

44. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16b

45. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Thalamus  Surrounds the third ventricle  The relay station for sensory impulses  Transfers impulses to the correct part of the cortex for localization and interpretation

46. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Hypothalamus  Under the thalamus  Important autonomic nervous system center  Helps regulate body temperature  Controls water balance  Regulates metabolism

47. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Hypothalamus (continued)  An important part of the limbic system (emotions)  The pituitary gland is attached to the hypothalamus

48. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Epithalamus  Forms the roof of the third ventricle  Houses the pineal body (an endocrine gland)  Includes the choroid plexus—forms cerebrospinal fluid

49. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Attaches to the spinal cord  Parts of the brain stem  Midbrain  Pons  Medulla oblongata

50. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem Figure 7.16a

51. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Midbrain  Mostly composed of tracts of nerve fibers  Has two bulging fiber tracts— cerebral peduncles  Has four rounded protrusions— corpora quadrigemina  Reflex centers for vision and hearing

52. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Pons  The bulging center part of the brain stem  Mostly composed of fiber tracts  Includes nuclei involved in the control of breathing

53. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Medulla Oblongata  The lowest part of the brain stem  Merges into the spinal cord  Includes important fiber tracts  Contains important control centers  Heart rate control  Blood pressure regulation  Breathing  Swallowing  Vomiting

54. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Reticular Formation  Diffuse mass of gray matter along the brain stem  Involved in motor control of visceral organs  Reticular activating system (RAS) plays a role in awake/sleep cycles and consciousness

55. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Reticular Formation of the Brain Stem Figure 7.16b

56. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebellum  Two hemispheres with convoluted surfaces  Provides involuntary coordination of body movements

57. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebellum Figure 7.16a