The nervous system

• What are the two parts of the nervous system?

  The central nervous system (CNS) and peripheral nerves
• What does the central nervous system consist of?

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

  Receptors detect stimuli from the environment
• What are neurons also known as?

  Neurons are also known as nerve cells
• What is the function of effectors in the nervous system?

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

  Muscles and glands
• How does the nervous system help humans react to their surroundings?

  It enables coordination of behavior through reflex actions
• What is the reflex arc and its importance?

  • The reflex arc is a neural pathway that controls reflex actions.
  • It allows for rapid responses to stimuli without conscious brain involvement.
  • Important for protecting the body from danger.
• What happens when you touch a hot object?

  The stimulus of heat is detected by a receptor in the skin
• What type of neuron carries the electrical impulse from the receptor to the central nervous system?

  A sensory neuron
• What occurs at the synapse between the sensory neuron and the relay neuron?

  A chemical is released that triggers an electrical impulse in the relay neuron
• What is the role of the relay neuron in the reflex arc?

  The relay neuron transmits the electrical impulse within the central nervous system
• What happens at the synapse between the relay neuron and the motor neuron?

  A chemical is released that triggers an electrical impulse in the motor neuron
• What is the final effect of the electrical impulse in the motor neuron?

  The muscle contracts, pulling the hand away from the heat
• Why are reflex actions considered automatic and rapid?

  Because they do not involve decision-making by the conscious part of the brain
• How do reflexes help protect us?

  They enable quick responses to potentially harmful stimuli