Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings C h a p t e r 13 The Spinal Cord, Spinal Nerves, and Spinal Reflexes PowerPoint® Lecture Slides prepared by Jason LaPres Lone Star College - North Harris Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Reflexes  Automatic responses coordinated within spinal cord  Through interconnected sensory neurons, motor neurons, and interneurons  Produce simple and complex reflexes

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Reflexes  Neural Reflexes  Rapid, automatic responses to specific stimuli  Basic building blocks of neural function  One neural reflex produces one motor response  Reflex arc  The wiring of a single reflex  Beginning at receptor  Ending at peripheral effector  Generally opposes original stimulus (negative feedback)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Reflexes Figure 13–15 Events in a Neural Reflex.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Spinal Reflexes Figure 13–17 A Stretch Reflex.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Spinal Reflexes  The Tendon Reflex  Prevents skeletal muscles from  Developing too much tension  Tearing or breaking tendons  Sensory receptors unlike muscle spindles or proprioceptors

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Spinal Reflexes Figure 13–19 A Flexor Reflex.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Brain Can Alter Spinal Reflexes  Integration and Control of Spinal Reflexes  Reflex behaviors are automatic  But processing centers in brain can facilitate or inhibit reflex motor patterns based in spinal cord

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Brain Can Alter Spinal Reflexes  The Babinski Reflexes  Normal in infants  May indicate CNS damage in adults

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Brain Can Alter Spinal Reflexes Figure 13–21 The Babinski Reflexes.