Nervous system

• What is homeostasis?

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

  Stimulus, receptor, coordination center, effector, response
• What are the two parts of the nervous system?

  Central nervous system and peripheral nerves
• What does the central nervous system consist of?

  Brain and spinal cord
• What do receptors do in the nervous system?

  Detect a stimulus and send impulses
• What are neurons also known as?

  Nerve cells
• What is the role of effectors in the nervous system?

  Bring about a response
• What are the two types of effectors mentioned?

  Muscles and glands
• How does the nervous system help humans?

  Enables reaction to surroundings and behavior coordination
• What is the reflex arc?

  A pathway for reflex actions
• What happens when you touch a hot object?

  The reflex arc is activated
• What is the stimulus in the reflex arc when touching a hot object?

  Heat
• What type of neuron carries impulses to the central nervous system?

  Sensory neuron
• What occurs at the synapse in the reflex arc?

  A chemical is released to trigger impulses
• What is the role of the relay neuron?

  Transmit impulses within the CNS
• What triggers an electrical impulse in the motor neuron?

  A chemical released at the synapse
• What is the effector in the reflex arc when touching a hot object?

  A muscle
• What is the response when you pull your hand away from heat?

  Muscle contraction
• Why are reflexes considered automatic?

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

  They enable rapid responses to danger
• What are the stages of the reflex arc?

  1. Stimulus detected by receptor
  2. Impulse travels along sensory neuron
  3. Impulse reaches synapse, triggering a chemical release
  4. Chemical triggers impulse in relay neuron
  5. Impulse travels to motor neuron
  6. Motor neuron sends impulse to effector
  7. Effector (muscle) contracts, pulling away
• What is the importance of the nervous system in homeostasis?

  • Detects changes in the environment
  • Coordinates responses to maintain stability
  • Facilitates rapid reactions to stimuli