Nervous system & Reflex arc

• What do large multicellular organisms like humans rely on for communication between body parts?

  Two organ systems
• What are the two organ systems involved in communication in humans?

  Nervous system and endocrine system
• What is another name for a nerve cell?

  Neuron
• How are neurons adapted to carry electrical impulses?

  They are long, thin, and branched
• What is the function of a synapse?

  It connects two nerve cells
• What happens when an electrical impulse reaches the end of a nerve cell?

  Chemicals are released across the synapse
• What triggers a new electrical impulse in the next nerve cell?

  Chemicals that diffuse across the synapse
• What is the central nervous system made up of?

  Brain and spinal cord
• What role does the central nervous system play?

  Processes sensory information and sends orders
• What do sensory neurons do?

  Carry information from receptors to CNS
• What type of information do sensory neurons carry?

  Changes in temperature or carbon dioxide levels
• What does the CNS do with the information it receives?

  Decides what needs to be done
• How does the CNS communicate its decisions to the body?

  Via motor neurons
• What are effectors generally?

  Muscles or glands
• What do effectors do in response to CNS orders?

  Contract or release hormones
• What is a reflex arc?

  Nerve pathway for unconscious reflexes
• Why are reflexes beneficial?

  They are rapid and automatic
• What happens when you touch a hot pan?

  Your hand moves away quickly
• What is the role of receptor cells in the reflex arc?

  Detect stimuli like pressure
• What does a sensory neuron do in a reflex arc?

  Carries impulse to the spinal cord
• What happens to the impulse in the spinal cord?

  It transfers to a relay neuron
• What does the relay neuron do in a reflex arc?

  Passes impulse to a motor neuron
• What does the motor neuron do in a reflex arc?

  Transmits impulse to an effector
• What is the role of the effector in a reflex arc?

  Contracts or moves body part
• What happens at the synapses between neurons?

  Electrical signals convert to chemical signals
• What is the main function of the nervous system?

  Detect changes and respond