1. The Nervous System & the control of movement Chapter 6

2. Q: What is the main role of the Nervous System? A: To “assemble info about conditions external & internal to the body, to analyze this information and initiate an appropriate response”. “COMMUNICATION NETWORK” A: To “assemble info about conditions external & internal to the body, to analyze this information and initiate an appropriate response”. “COMMUNICATION NETWORK”

4. What are the 2 Major Components of the Nervous System? 1. The Central Nervous System 2. The Peripheral Nervous System 1. The Central Nervous System 2. The Peripheral Nervous System

5. CNS (Central Nervous System)  Two Parts: A) The Brain B) The Spinal Cord (& vertebral column)  Two Parts: A) The Brain B) The Spinal Cord (& vertebral column)

6. CNS ‘A’ - The Brain  Main control center for survival  Emotions  The brain is made up of 6 parts:  Main control center for survival  Emotions  The brain is made up of 6 parts:

7. The 6 Brain Segments 1) Cerebrum: -largest section -controls sensory, motor & intelligence functions -2 hemispheres / 8 ‘lobes’ 1) Cerebrum: -largest section -controls sensory, motor & intelligence functions -2 hemispheres / 8 ‘lobes’

8. The 6 Brain Segments (continued) 2) Cerebellum - coordinates balance & muscle movement 3) Brain Stem - links cerebrum to the spinal cord ---> Autonomic functions like “muscle tone” 2) Cerebellum - coordinates balance & muscle movement 3) Brain Stem - links cerebrum to the spinal cord ---> Autonomic functions like “muscle tone”

9. The 6 Brain Segments (continued) 4. Diencephalon -divided into the: 4. Diencephalon -divided into the: i)Thalemus -pain & attention ii) Hypothalemus -appetite -emotions -body temperature

10. The 6 Brain Segments (continued) 5. Limbic System: -regulates basic drives like hunger, emotions, aggression 6. Reticular Activating System -crucial for maintaining consciousness 5. Limbic System: -regulates basic drives like hunger, emotions, aggression 6. Reticular Activating System -crucial for maintaining consciousness

11. CNS ‘B’ - Spinal Cord (& Vertebral Column)  Main info pathway between brain & PNS  Spinal Cord - 45cm (brain stem to L2)  Spinal Nerves carry: -sensory info to CNS & -motor commands away from CNS  Main info pathway between brain & PNS  Spinal Cord - 45cm (brain stem to L2)  Spinal Nerves carry: -sensory info to CNS & -motor commands away from CNS

12. What are the 2 Major Components of the Nervous System? 1. The Central Nervous System 2. The Peripheral Nervous System 1. The Central Nervous System 2. The Peripheral Nervous System

13. PNS (Peripheral Nervous System)  12 Cranial Nerves / 31 Spinal Nerves (sensory fibers)  Responsible for voluntary actions & bodily functions  Eg heart beat, muscle control  Made of Autonomic NS & Somatic NS  Efferent nerves (motor) - carry info from CNS to organs ( E fferent-->muscles)  Afferent nerves (sensory)- carry info to brain --> A fferent-->br a in)  12 Cranial Nerves / 31 Spinal Nerves (sensory fibers)  Responsible for voluntary actions & bodily functions  Eg heart beat, muscle control  Made of Autonomic NS & Somatic NS  Efferent nerves (motor) - carry info from CNS to organs ( E fferent-->muscles)  Afferent nerves (sensory)- carry info to brain --> A fferent-->br a in)

14. PNS ‘A’- Autonomic Nervous System  Involuntary i) Sympathetic System: -prepares body for emergencies (fight or flight response) ii) Parasympathetic System: -returns boy to normal after ‘emergency’  Involuntary i) Sympathetic System: -prepares body for emergencies (fight or flight response) ii) Parasympathetic System: -returns boy to normal after ‘emergency’

15. PNS ‘B’- Somatic Nervous System Components: -afferent & efferent nerve fibers -PNS controls and knows what our muscles/tendons are doing & feeling (ie pain, cold, balance, etc.) Components: -afferent & efferent nerve fibers -PNS controls and knows what our muscles/tendons are doing & feeling (ie pain, cold, balance, etc.)

16. REFLEX ARC -Automatic response to stimulation -if command center for the flex is: a)the brain ---> cerebral reflex arc b)the spinal cord --->spinal reflex arc -Automatic response to stimulation -if command center for the flex is: a)the brain ---> cerebral reflex arc b)the spinal cord --->spinal reflex arc

17. Autonomic Reflexes -some involve smooth muscle, cardiac muscle, glands -regulates digestion, blood pressure, sweating -some involve smooth muscle, cardiac muscle, glands -regulates digestion, blood pressure, sweating

18. Somatic Reflexes -involve stimulation of skeletal muscle ie -stretch reflex, withdrawl reflex -involve stimulation of skeletal muscle ie -stretch reflex, withdrawl reflex

19. Basic Reflex Arc  The components of a basic reflex include; i) receptor ii) adjustor iii) effector  The components of a basic reflex include; i) receptor ii) adjustor iii) effector

20. Reflex Arc The components of a reflex arc include; i) receptor ii) sensory or AFFERENT nerve (brain) iii) intermediate nerve fibers (adjustor) which interprets the signal & issues an appropriate response iii) motor or Efferent nerve (muscle) v) effector organ (muscle) -if command center for the flex is: a)the brain ---> cerebral reflex arc b)the spinal cord --->spinal reflex arc The components of a reflex arc include; i) receptor ii) sensory or AFFERENT nerve (brain) iii) intermediate nerve fibers (adjustor) which interprets the signal & issues an appropriate response iii) motor or Efferent nerve (muscle) v) effector organ (muscle) -if command center for the flex is: a)the brain ---> cerebral reflex arc b)the spinal cord --->spinal reflex arc

21. Proprioceptors Provide info re: - muscle contraction - position of limbs - body posture - balance Provide info re: - muscle contraction - position of limbs - body posture - balance

22. Proprioceptors There are 2 receptors: i) Golgi Tendon Organs (GTO) ii) Muscle Spindles There are 2 receptors: i) Golgi Tendon Organs (GTO) ii) Muscle Spindles

23. Golgi Tendon Organs - tension detectors - In the tendon of the muscle - Tension Reflex: GTO, Afferent Neuron, CNS, Efferent Neuron, Motor unit - tension detectors - In the tendon of the muscle - Tension Reflex: GTO, Afferent Neuron, CNS, Efferent Neuron, Motor unit

24. Muscle Spindles -senses changes in muscle length -2 afferent neurons & 1 efferent neuron -very sensitive “Stretch Reflex” (see table 6.1 on pg. 101 in text) -senses changes in muscle length -2 afferent neurons & 1 efferent neuron -very sensitive “Stretch Reflex” (see table 6.1 on pg. 101 in text)