The Nervous System

• What is the process by which the human body keeps internal conditions as constant as possible called?

  Homeostasis
• What does homeostasis involve?

  Automatic control systems
• According to the video, what does every automatic control system have?

  Stimulus, receptor, coordination center, effector, response
• Which system is a key part of homeostasis?

  The nervous system
• What are the two main parts of the nervous system?

  Central nervous system (CNS) and other nerves
• What does CNS stand for?

  Central Nervous System
• What does the central nervous system consist of?

  The brain and the spinal cord
• What do receptors do?

  Detect a stimulus
• What do receptors send down neurons to the central nervous system?

  Electrical impulses
• What is another way of saying nerve cells?

  Neurons
• What is the central nervous system's role in automatic control systems?

  Coordination Center
• What does the central nervous system send down other neurons to effectors?

  Electrical impulses
• What do effectors do?

  Bring about a response
• What are effectors usually?

  A muscle or a gland
• What does a muscle do when it acts as an effector?

  Contracts
• What does a gland do when it acts as an effector?

  Secretes a hormone
• What is a key role of the nervous system?

  Enables humans to react and coordinate behavior
• How does the nervous system enable humans to react and coordinate their behavior?

  Through the reflex arc
• What is a common exam topic mentioned in the video?

  The reflex arc
• What are sensory neurons connected to?

  Receptors
• What do receptors allow us to do?

  Sense our environment
• What is the junction at the end of a sensory neuron called?

  A synapse
• What is released at a synapse?

  A chemical
• Where does the chemical released at the synapse diffuse to?

  A relay neurone
• What does the chemical diffusing to a relay neuron trigger?

  An electrical impulse
• What is released at the synapse connected to the relay neurone?

  A chemical
• What does the chemical at the synapse connected to the relay neurone trigger in a motor neuron?

  An electrical impulse
• Where does the electrical impulse pass down in a motor neuron?

  To an effector
• What is pulling the hand away from the heat called?

  The response
• In most cases, which part of the central nervous system makes decisions about actions?

  The brain
• What does the conscious part of the brain not do in the case of reflexes?

  Make decisions
• What characteristic makes reflexes automatic?

  No decision-making by the conscious brain
• Why are reflexes rapid?

  To protect us from danger
• What are the stages of the reflex arc in order?

  • Stimulus
  • Receptor
  • Sensory neuron
  • Synapse
  • Relay neuron
  • Synapse
  • Motor neuron
  • Effector
  • Response
• What are sensory neurons connected to, which allow us to sense our environment?

  Receptors
• What is the role of the Coordination Center in automatic control systems?

  Sends electrical impulses down other neurons to effectors