Structure and function

• What does the nervous system detect and respond to?

  Stimuli (changes in the environment)
• What is the primary function of the nervous system?

  To coordinate responses for survival and function
• What are the two main parts of the nervous system?

  • Central Nervous System (CNS): Brain and spinal cord
  • Peripheral Nervous System (PNS): Nerves connecting CNS to body
• What do receptors in the nervous system do?

  Detect stimuli like light and sound
• What is the role of sensory neurones?

  Carry impulses from receptors to the CNS
• What do relay neurones do?

  Transmit impulses between sensory and motor neurones
• What is the function of motor neurones?

  Carry impulses from the CNS to effectors
• What are effectors in the nervous system?

  Muscles or glands that produce a response
• What are reflex actions?

  Fast, automatic responses not involving the brain
• Why are reflexes important?

  They protect the body from harm
• What are the steps in a reflex arc?

  1. Stimulus detected by a receptor
  2. Sensory neurone carries impulse to spinal cord
  3. Impulse transmitted to relay neurone
  4. Relay neurone passes signal to motor neurone
  5. Motor neurone sends impulse to effector
  6. Effector responds (e.g., muscle contracts)
• What do dendrites do in a neurone?

  Receive electrical impulses from other neurones
• What is the function of the cell body in a neurone?

  Contains the nucleus and controls cell function
• What does the axon do in a neurone?

  Carries electrical impulses away from the cell body
• What is the role of the myelin sheath?

  Insulates the axon, speeding up impulse transmission
• What is a synapse?

  A small gap between neurones
• How do signals travel across a synapse?

  Transmitted chemically using neurotransmitters
• What are the steps of how a synapse works?

  1. Electrical impulse reaches neurone end
  2. Neurotransmitters are released
  3. Neurotransmitters diffuse across synapse
  4. Bind to receptors on next neurone
  5. New electrical impulse is triggered
• Why are synapses important?

  They ensure signals travel in one direction
• What is the main organ of the nervous system?

  The brain
• What does the cerebral cortex control?

  Memory, intelligence, and consciousness
• What is the function of the cerebellum?

  Controls balance and coordination
• What does the medulla control?

  Involuntary actions like heartbeat and breathing
• What is the role of the hypothalamus?

  Regulates body temperature and hormones
• What does the pituitary gland do?

  Releases hormones that control body functions
• How do scientists study the brain?

  1. Studying brain damage and behavior changes
  2. Electrically stimulating different brain areas
  3. MRI scans for detailed brain activity images
• What are the differences between the nervous and hormonal systems?

  • Nervous System: Electrical impulses, very fast, short-lived, specific neurones, localised effects
  • Hormonal System: Chemical hormones, slower, long-lasting, bloodstream, widespread effects
• What is Parkinson’s Disease?

  Damage to nerve cells causing movement problems
• What is Alzheimer’s Disease?

  Brain cells lost, leading to memory loss
• What is Multiple Sclerosis?

  Damage to the myelin sheath slows nerve impulses
• What are the main nervous system disorders mentioned?

  • Parkinson’s Disease
  • Alzheimer’s Disease
  • Multiple Sclerosis