nervous system

• What are the two organ systems that help large multicellular organisms communicate and coordinate behavior?

  The nervous system and the endocrine system
• Why do large multicellular organisms like humans need a communication system?

  To coordinate behavior and respond to their surroundings
• What are the main topics to know about the nervous system?

  • Structure of a nerve cell (neuron)
  • Structure of the whole nervous system
  • How a reflex arc works
• What is another name for a nerve cell?

  Neuron
• How are neurons adapted to carry electrical impulses?

  They are long, thin, and have many branch connections
• What is the function of a synapse in the nervous system?

  It allows communication between nerve cells
• What happens when an electrical impulse reaches the end of a nerve cell?

  It causes the release of chemicals that diffuse across the synapse
• How does the nervous system function as a whole when considering many neurons?

  It consists of approximately 100 billion neurons working together
• What are the two main parts of the central nervous system?

  The brain and the spinal cord
• What role does the central nervous system play in processing information?

  It takes in sensory information, decides on actions, and sends orders to the body
• What type of neurons carry information from receptors to the central nervous system?

  Sensory neurons
• What type of information do sensory neurons convey to the central nervous system?

  Information about changes in temperature or carbon dioxide levels
• What do motor neurons do in the nervous system?

  They send impulses back out to effectors
• What are effectors in the context of the nervous system?

  Muscles or glands that respond to impulses
• What is a reflex arc?


  • A nerve pathway underlying unconscious reflexes
  • Involves sensory neurons, relay neurons, and motor neurons
  • Enables rapid and automatic responses to stimuli
• What is an example of a reflex action?


  Moving your hand away from a hot pan
• What is the benefit of reflexes in the nervous system?

  They allow for rapid and automatic responses to avoid harm
• How does a sensory neuron function in a reflex arc?


  It carries an impulse from the receptor to the spinal cord
• What happens to the impulse in the spinal cord during a reflex action?

  It is transferred to a relay neuron
• What is the role of the motor neuron in a reflex arc?


  It carries the impulse back to an effector
• What is the role of synapses in the transmission of impulses between neurons?

  They convert electrical signals to chemical signals for transmission