Unit 4

• Main functions of the Central Nervous System:

  • Receive information from the senses
  • Process information
  • Bring about an appropriate response
• Components of the Central Nervous System:

  • The brain
  • The spinal cord
• Two responses stimulated by motor nerves:

  • Muscle Contraction
  • Glandular Secretion
• Two systems of the Peripheral Nervous System:

  • Autonomic
  • Somatic
• Main function of the Somatic Nervous System:

  • Controls the skeletal muscles
• Types of nerves involved in the Somatic Nervous System:

  • Motor nerves
  • Sensory nerves
• Pathway of a somatic nervous response:

  • Stimulus
  • Sensory nerve
  • Central Nervous System (CNS)
  • Motor nerve
  • Effector
• Two types of reactions in the Autonomic Nervous System:

  • Sympathetic
  • Parasympathetic
• Preparation of the body by the sympathetic system:

  • Fight or Flight
• Preparation of the body by the parasympathetic system:

  • Rest and Digest
• Effect of the sympathetic system on heart rate:

  • Increased contraction of cardiac muscles – increases cardiac output
• Effect of the sympathetic system on peristalsis:

  • Rate of contraction of smooth muscle in digestive tract decreased - decreases rate of peristalsis
• Effect of the sympathetic system on breathing rate:

  • Smooth muscle wall of bronchioles relaxed - increased intake of air
• Effect of the sympathetic system on intestinal secretions:

  • Activity of the secretory glands inhibited – decreased production of intestinal secretions
• Effect of the parasympathetic system on heart rate:

  • Decreased contraction of cardiac muscles – decreases cardiac output
• Effect of the parasympathetic system on breathing rate:

  • Smooth muscle wall of bronchioles contracted - decreased intake of air
• Effect of the parasympathetic system on peristalsis:

  • Rate of contraction of smooth muscle in digestive tract increased - increased rate of peristalsis
• Effect of the parasympathetic system on intestinal secretions:

  • Activity of the secretory glands stimulated –increased production of intestinal secretions
• Function of the cerebral cortex:

  • The centre of conscious thought
  • Coordinates movement
  • Makes decisions in light of experience
• Left cerebral hemisphere information source and control:

  • Gets information from the right visual field
  • Controls the right side of the body
• Right cerebral hemisphere information source and control:

  • Gets information from the left visual field
  • Controls the left side of the body
• What is memory?

  • The storage, retention and retrieval of information
• Examples of memories:

  • Past experiences
  • Knowledge
  • Thoughts
• Sensory memory:

  • Lasts a few seconds
  • Retains all of the visual or auditory input
• Short term memory:

  • Can store around 7 items for about 30 seconds
• Loss of items from short term memory:

  • Displacement
  • Decay
• Method of increasing short term memory span:

  • Chunking
• Advantage of rehearsal:

  • Extends the time information is stored in the short term memory
• Serial position effect:

  • Objects in the middle of a list are more likely to be forgotten than those at the beginning or end
• Reason objects at the beginning of the list are remembered:

  • They have been rehearsed and may have been transferred to the LTM
• Reason objects at the end of the list are remembered:

  • They are still in the STM
• How is information transferred from STM to LTM?

  • Rehearsal
  • Organisation
  • Elaboration
• Encoding involving repetition:

  • Shallow encoding
• Encoding involving associating information and linking it with previous memories:

  • Elaborative encoding
• Components of a neuron:

  • Dendrites
  • Cell body
  • Axon
• Direction dentrites carry an impulse:

  • Towards a cell body
• Direction axons carry an impulse:

  • Away from the cell body
• Material that insulates a nerve:

  • Myelin
• Difference in responses to stimuli in the first two years of life compared to adults:

  • Not as rapid as there are slower impulses
• Where sensory neurons carry impulses from and to:

  • Into the Central Nervous System (CNS) from sense organs