BIO 4TH

• Nervous system


  Complex network of nerves that carry messages throughout the entire body
• Nervous system


  From the brain to the spinal cord to the rest of the body
• Peripheral nervous system


  Sends messages to and from the CNS via neurons
• Peripheral nervous system


  • Sensory neurons
  • Motor neurons
• Sensory neurons


  Pick up information from senses
• Autonomic nervous system


  Responsible for involuntary responses
• Autonomic nervous system


  • Breathing
  • Digestion
  • Stress response
  • Heart rate
• Autonomic nervous system


  Controls smooth and cardiac muscles and glands
• Autonomic nervous system control centers


  In the brain stem
• Sympathetic branch


  Fight or flight response
• Parasympathetic branch


  Conserve and restore body energy when relaxed
• Somatic nervous system


  Responsible for voluntary movements
• Somatic nervous system


  • Walking
  • Eating
  • Sleeping
  • Jumping
• Somatic nervous system


  Controls skeletal muscles
• Somatic nervous system


  Carries commands from the motor cortex
• Somatic nervous system


  Connects the CNS and the senses
• Central nervous system


  Composed of the brain and spinal cord
• Central nervous system


  Relay neurons
• Brain


  Receives and processes information from the senses
• Brain


  Center of conscious awareness
• Brain


  Responsible for higher mental functions
• Brain


  Generates memories and thoughts
• Brain


  Initiates responses
• Brain


  Stores memories
• Spinal cord


  Conducts signals to and from the brain
• Spinal cord


  Connects the nerves to the PNS
• Spinal cord


  Controls reflex actions
• Spinal cord reflex action


  • Removing hand when it touches a hot plate
• Higher mental functions


  Human ability to take knowledge and learning and use it to create new ideas, things and concepts
• Neurons


  Also known as nerve cells
• Neuron types


  • Sensory
  • Motor
  • Relay
• Sensory neurons


  Carry nerve impulses from sensory receptors toward the central nervous system and brain
• Sensory neurons


  When nerve impulses reach the brain, they are translated to "sensations"
• Sensory information


  • Chemical
  • Physical
• Motor neurons


  Responsible for carrying signals away from the central nervous system toward muscles to cause movement
• Motor neurons


  • Lower motor neurons
  • Upper motor neurons
• Lower motor neurons


  Neurons that travel from the spinal cord to the muscles of the body
• Upper motor neurons


  Neurons that travel between the brain and the spinal cord
• Relay neurons


  Allow sensory and motor neurons to communicate with each other
• Relay neurons


  Communicate with each other by forming circuits of differing complexities