1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture prepared by Kathleen A. Ireland, Seabury Hall, Maui, Hawaii Anatomy & Physiology M A R T I N I FIRST EDITION C h a p t e rs 15-16 Neural Integration: Sensory Pathways&Somatic Nervous System PowerPoint® Lecture Slides prepared by Jason LaPres Lone Star College - North Harris Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Neural pathways Afferent pathways Sensory information coming from the sensory receptors through peripheral nerves to the spinal cord and on to the brain Efferent pathways Motor commands coming from the brain and spinal cord, through peripheral nerves to effecter organs

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.1 An Overview of Neural Integration Figure 15.1

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Specialized cell or cell process that monitors specific conditions Arriving information is a sensation Awareness of a sensation is a perception Sensory receptor

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings General senses Pain Temperature Physical distortion Chemical detection Receptors for general senses scattered throughout the body Special senses Located in specific sense organs Structurally complex Senses

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Each receptor cell monitors a specific receptive field Transduction A large enough stimulus changes the receptor potential, reaching generator potential Sensory receptors

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Tonic receptors Always active Slow acting receptors Phasic receptors Provide information about the intensity and rate of change of a stimulus Fast acting receptors Adaptation Reduction in sensitivity in the presence of a constant stimulus Receptors

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of nociceptor Provide information on pain as related to extremes of temperature Provide information on pain as related to extremes of mechanical damage Provide information on pain as related to extremes of dissolved chemicals Myelinated type A fibers carry fast pain Slower type C fibers carry slow pain The general senses

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.2 Figure 15.2 Receptors and Receptive Fields

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Found in the dermis Mechanoceptors Sensitive to distortion of their membrane Tactile receptors (six types) Baroreceptors Proprioceptors (three groups) Thermoceptors and mechaniceptors

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.3 Tactile Receptors in the Skin Figure 15.3a-f

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chemoreceptors Carotid bodies Aortic bodies Chemoreceptors

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings First order neurons Sensory neurons that deliver sensory information to the CNS Second order neurons First order neurons synapse on these in the brain or spinal cord Third order neurons Found in the thalamus Second order neurons synapse on these First, second, and third order neurons

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three major pathways carry sensory information Posterior column pathway Anterolateral pathway Spinocerebellar pathway Somatic sensory pathways

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.4 Figure 15.4 Sensory Pathways and Ascending Tracts in the Spinal Cord

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Carries fine touch, pressure and proprioceptive sensations Axons ascend within the fasciculus gracilis and fasciculus cuneatus Relay information to the thalamus via the medial lemniscus Decussation Posterior column pathway

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.5a, b Figure 15.5 The Posterior Column Pathway and the Spinothalamic Tracts

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Carries poorly localized sensations of touch, pressure, pain, and temperature Axons decussate in the spinal cord and ascend within the anterior and lateral spinothalamic tracts Headed toward the ventral nuclei of the thalamus Anterolateral pathway

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 54.5c Figure 15.5 The Posterior Column Pathway and the Spinothalamic Tracts

20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Includes the posterior and anterior spinocerebellar tracts Carries sensation to the cerebellum concerning position of muscles, tendons and joints Spinocerebellar pathway

21. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.6 Figure 15.6 The Spinocerebellar Pathway

22. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Carry information collected by interoceptors Information from cranial nerves V, VII, IX and X delivered to solitary nucleus in medulla oblongata Dorsal roots of spinal nerves T1 – L2 carry visceral sensory information from organs between the diaphragm and pelvis Dorsal roots of spinal nerves S2 – S4 carry sensory information below this area Visceral sensory pathways

23. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Upper motor neuron Cell body lies in a CNS processing center Lower motor neuron Cell body located in a motor nucleus of the brain or spinal cord Somatic motor pathways

24. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.7 Figure 15.7 Descending (Motor) Tracts in the Spinal Cord

25. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Provides voluntary skeletal muscle control Corticobulbar tracts terminate at cranial nerve nuclei Corticospinal tracts synapse on motor neurons in the anterior gray horns of the spinal cord Visible along medulla as pyramids The Corticospinal pathway

26. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Most of the axons decussate to enter the descending lateral corticospinal tracts Those that do not cross over enter the anterior corticospinal tracts Provide rapid direct method for controlling skeletal muscle Pyramids

27. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15.8 Figure 15.8 The Corticospinal Pathway

28. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The medial and lateral pathways Issue motor commands as a result of subconscious processing Medial pathway Primarily controls gross movements of the trunk and proximal limbs Includes the vestibulospinal tracts, tectospinal tracts and reticulospinal tracts Medial and lateral pathways

29. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lateral pathway Controls muscle tone and movements of the distal muscles of the upper limbs Rubrospinal tracts Lateral pathways

30. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Basal nuclei adjust motor commands issued in other processing centers Provide background patterns of movement involved in voluntary motor movements Cerebellum monitors proprioceptive information, visual information and vestibular sensations The basal nuclei and cerebellum

31. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Levels of processing and motor control Spinal and cranial reflexes provide rapid, involuntary, preprogrammed responses Voluntary responses More complex Require more time to prepare and execute Control and responses

32. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Spinal and cranial reflexes are first to appear Complex reflexes develop as CNS matures and brain grows During development

33. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Coordinates cardiovascular, respiratory, digestive, urinary and reproductive functions Preganglionic neurons in the CNS send axons to synapse on ganglionic neurons in autonomic ganglia outside the CNS ANS

34. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Divisions of the ANS Sympathetic division (thoracolumbar, “fight or flight”) Thoracic and lumbar segments Parasympathetic division (craniosacral, “rest and repose”) Preganglionic fibers leaving the brain and sacral segments

35. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Preganglionic neurons between segments T 1 and L 2 Ganglionic neurons in ganglia near vertebral column Specialized neurons in adrenal glands Sympathetic division anatomy

36. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.10 The Organization of the Sympathetic Division of the ANS Figure 16.10

37. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sympathetic chain ganglia (paravertebral ganglia) Collateral ganglia (prevertebral ganglia) Sympathetic ganglia

38. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.11 Sympathetic Pathways Figure 16.11a

39. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.11 Sympathetic Pathways Figure 16.11b

40. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.11 Sympathetic Pathways Figure 14511c

41. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Segments T 1 -L 2, ventral roots give rise to myelinated white ramus Leads to sympathetic chain ganglia Organization and anatomy of the sympathetic division

42. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.12 Figure 16.12 The Distribution of Sympathetic Innervation Animation: The sympathetic division PLAY

43. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rejoin spinal nerves and reach their destination by way of the dorsal and ventral rami Those targeting structures in the thoracic cavity form sympathetic nerves Go directly to their destination Postganglionic fibers

44. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sympathetic innervation via preganglionic fibers that synapse within collateral ganglia Splanchic nerves Abdominopelvic viscera

45. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Celiac ganglion Innervates stomach, liver, gall bladder, pancreas, spleen Superior mesenteric ganglion Innervates small intestine and initial portion of large intestine Inferior mesenteric ganglion Innervates kidney, urinary bladder, sex organs, and final portion of large intestine Abdominopelvic viscera

46. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings In crises, the entire sympathetic division responds Sympathetic activation Affects include increased alertness, energy and euphoria, increased cardiovascular and respiratory activities, elevation in muscle tone, mobilization of energy resources Sympathetic activation

47. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Stimulation of sympathetic division has two distinct results Release of ACh or NE at specific locations Secretion of E and NE into general circulation Most postganglionic fibers are adrenergic, a few are cholinergic or nitroxidergic Two types of receptors are alpha receptors and beta receptors Sympathetic ganglionic neurons end in telodendria studded with varicosities filled with neurotransmitter Neurotransmitters and sympathetic function

48. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Preganglionic neurons in the brainstem and sacral segments of spinal cord Ganglionic neurons in peripheral ganglia located within or near target organs Parasympathetic division

49. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.13 Figure 16.13 The Organization of the Parasympathetic Division of the ANS

50. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Preganglionic fibers leave the brain as cranial nerves III, VI, IX, X Sacral neurons form the pelvic nerves Organization and anatomy of the parasympathetic division

51. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.14 Figure 16.14 The Distribution of Parasympathetic Innervation

52. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Effects produced by the parasympathetic division Relaxation Food processing Energy absorption Parasympathetic activation

53. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings All parasympathetic fibers release ACh Short-lived response as ACH is broken down by AChE and tissue cholinesterase Postsynaptic membranes have two kinds of receptors Muscarinic Nicotinic Neurotransmitters and parasympathetic functions

54. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sympathetic Widespread influence on visceral and somatic structures Parasympathetic Innervates only visceral structures serviced by cranial nerves or lying within the abdominopelvic cavity Dual innervation = organs that receive input from both systems Sympathetic and parasympathetic divisions

55. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sympathetic and parasympathetic systems intermingle to form autonomic plexuses Cardiac plexus Pulmonary plexus Esophageal plexus Celiac plexus Inferior mesenteric plexus Hypogastric plexus Anatomy of dual innervation

56. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.15 The Autonomic Plexuses Figure 16.15

57. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Important physiological and functional differences exist Comparison of the two divisions

58. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.16 Figure 16.16 Summary: The Anatomical Differences between the Sympathetic and Parasympathetic Divisions

59. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Visceral reflex arcs are the simplest function of the ANS Long reflexes (interneurons) Short reflexes (bypassing CNS) Parasympathetic reflexes govern respiration, cardiovascular function and other visceral activities Visceral reflexes

60. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.17 Visceral Reflexes Figure 16.17

61. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Activity in the ANS is controlled by centers in the brainstem that deal with visceral functioning Higher levels of autonomic control

62. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Integration occurs at the brainstem and higher centers SNS and ANS organized in parallel

63. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Are performed by the cerebral cortex and involve complex interactions Involve conscious and unconscious information processing Are subject to modification and adjustment over time Higher order functions

64. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Short term or long term Memory consolidation is moving from short term to long term Amnesia is the loss of memory due to disease or trauma Memory

65. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.14 Memory Storage Figure 16.14

66. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Deep sleep, the body relaxes and cerebral cortex activity is low REM sleep active dreaming occurs The reticular activating system (RAS) is important to arousal and maintenance of consciousness Consciousness

67. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 16.20 The Reticular Activating System Figure 16.20

68. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings You should now be familiar with: The components of the afferent and efferent divisions of the nervous system, and what is meant by the somatic nervous system. Why receptors respond to specific stimuli and how the organization of a receptor affects its sensitivity. The major sensory pathways. How we can distinguish among sensations that originate in different areas of the body. The components, processes and functions of the somatic motor pathways. The levels of information processing involved in motor control.

69. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings You should now be familiar with: The organization of the autonomic nervous system. The structures and functions of the sympathetic and parasympathetic divisions of the ANS. The mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. The effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. The hierarchy of interacting levels of control in the ANS. How memories are created, stored and recalled.