The Nervous System

• What is homeostasis?

  Maintaining constant internal conditions
• What are the components of an automatic control system?

  Stimulus, receptor, coordination center, effector, response
• What does the central nervous system consist of?

  Brain and spinal cord
• What is the role of receptors in the nervous system?

  Detect stimuli and send impulses
• What are neurons?

  Nerve cells that transmit impulses
• What is the function of effectors?

  Bring about a response
• How do reflex actions help humans?

  They enable rapid responses to danger
• What is the structure of the reflex arc?

  1. Stimulus detected by receptor
  2. Impulse travels along sensory neuron
  3. Impulse reaches synapse, triggering relay neuron
  4. Relay neuron sends impulse to motor neuron
  5. Motor neuron transmits impulse to effector
  6. Effector (muscle) contracts, response occurs
• What is the stimulus in the reflex arc when touching a hot object?

  Heat
• What happens at the synapse in the reflex arc?

  A chemical is released to trigger an impulse
• What is the role of the motor neuron in the reflex arc?

  Transmits impulse to the effector
• What is the response when touching a hot object?

  Pulling the hand away
• Why are reflex actions considered automatic?

  They do not involve conscious decision-making
• How do reflexes protect us?

  By enabling rapid responses to danger
• What are the key differences between reflex actions and voluntary actions?

  • Reflex actions are automatic and rapid
  • Voluntary actions involve conscious decision-making
  • Reflexes bypass the brain's decision-making process
  • Voluntary actions require time for thought and planning