nervous system

• Why do large multicellular organisms need a way to communicate between different parts of their body?

  To coordinate behavior and respond to surroundings
• What are the two organ systems that humans rely on for communication and coordination?

  Nervous system and endocrine system
• What are the three main things to understand about the nervous system?

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

  Neuron
• What is the adaptation of neurons that allows them to carry electrical impulses effectively?

  They're long, thin, and have branched connections
• What is the role of a synapse in nerve cell communication?

  It's a connection between two nerve cells
• What happens when an electrical impulse reaches the end of a nerve cell?

  Chemicals are released to trigger another impulse
• What is the result of the chemicals diffusing across the gap in a synapse?

  It triggers another electrical impulse
• Approximately how many nerve cells make up the human nervous system?

  100 billion
• What two structures make up the central nervous system?

  Brain and spinal cord
• What is the main function of the central nervous system?

  Thinking, information processing, and sending orders
• How does the central nervous system receive information from the rest of the body?

  Through sensory neurons
• What do sensory neurons carry information about?

  Changes in temperature or carbon dioxide levels
• What does CNS stand for?

  Central nervous system
• How does the central nervous system send impulses back out to the body?

  Via motor neurons
• What are the two main types of effectors?

  Muscles and glands
• What are effectors instructed to do?

  Contract or release hormones
• What is the overall function of the nervous system?

  Detect, sort, and respond to changes
• What is a reflex arc a technical term for?

  Unconscious nerve pathway
• What is the main benefit of having reflexes?

  Rapid and automatic responses
• Why are rapid responses beneficial?

  Helps us avoid getting hurt
• What is stimulated by the receptor cells in the skin?

  A sensory neuron
• Where does the sensory neuron carry the impulse from the finger?

  Up to the spinal cord
• In the spinal cord, which neuron does the sensory neuron transfer the impulse to?

  Relay neuron
• Which neuron carries the impulse back out to the body?

  Motor neuron
• What does the bicep do in response to the impulse?

  Contracts and moves the hand
• What happens between each of the different neurons?

  Electrical signal converts to chemical signal