9.4 mammal nervous sytem

• what does the nervous system consist of?

  • Central Nervous System
  • Peripheral Nervous system
• Central nervous system

  • consists of brain and spinal chord
• peripheral nervous system

  
  

  • consists of autonomic and somatic system
• autonomic system


  • divided into sympathetic and parasympathetic system
  • controls involuntary responses
  • e.g heart rate
  • sympathetic and parasympathetic are antagonistic.
• somatic system

  • controls voluntary responses
• sympathetic system


  • coordinates fight or flight
  • releases noradrenaline
  • increases heart rate
  • ganglia close to CNS
• parasympathetic system


  • coordinates rest and digest
  • releases acetylcholine
  • slows heart rate
  • ganglia far from CNS
• structure of spinal chord

  
  

  • cylinder bundle of nerve fibres
  • from the brain to lower back
  • surrounded by spinal vertebrae
  • white matter - myelinated axon
  • grey matter - H shaped, contains neurons
• reflex pathway

  • sensory nerve fibre enters through dorsal root
  • carrying electrical impulse from sensory neurone
  • relay neuron passes impulse to motor neurone
  • motor neurone fibres exit from ventral root
  • stimulate effector
• parts of the brain

  • medulla oblongata
  • cerebrum
  • cerebellum
  • hypothalamus
• medulla oblongata


  • controls breathing and heart rate
• cerebellum


  • controls balance and coordination of movement
• cerebrum


  • control higher function
  • responsible for conscious thoughts
  • initiates movement
• hypothalamus


  • regulates temperature
  • osmoregulation