B5.2

• What is the primary function of the central nervous system (CNS)?

  To receive, process, and relay information for responses.
• What are the two main components of the central nervous system?

  The brain and spinal cord.
• What is the role of the peripheral nervous system (PNS)?


  To transmit and receive information from the central nervous system.
• What is the function of synapses in the nervous system?

  To allow neurons to exchange impulses with one another.
• What are the four essential parts of a neuron?

  • Dendrites
  • Axons
  • Cell body
  • Myelin sheath
• What is the role of the myelin sheath?

  To insulate and speed up nerve impulse transmission.
• What is the difference between a neurone and a nerve?

  A neurone is a single nerve cell, while a nerve is a collection of neurones.
• How do neurons transmit nerve impulses?

  Through synaptic clefts using neurotransmitters.
• What happens when neurotransmitters are released from the presynaptic neuron?

  They diffuse across the synaptic cleft to the postsynaptic neuron.
• What is the function of reuptake channels?

  To remove neurotransmitters from the synaptic cleft.
• What occurs if not enough neurotransmitter is produced at the synapse?

  No response occurs due to insufficient binding to receptors.
• What happens if too much neurotransmitter is produced?

  Overstimulation occurs, taking longer to clear from the synaptic cleft.
• What are the steps involved in a reflex action?

  1. Register a stimulus
  2. Generate an electrical impulse to the sensory neuron
  3. Sensory neuron sends impulse to processing center (relay neuron)
  4. Relay neuron sends impulse to motor neuron
  5. Motor neuron triggers the effector to move
• What part of the brain is responsible for conscious processes and high-order thinking?

  The cerebral cortex.
• What is the function of the hypothalamus?

  To process sensory information.
• What does the pituitary gland secrete?

  Hormones.
• What is the role of the cerebellum?

  To maintain balance and movement.
• What is the function of the brain stem?

  To control unconscious processes.
• Which lobe of the brain is responsible for vision?

  The occipital lobe.
• What is the function of the temporal lobe?

  To process hearing.
• What higher-order functions does the frontal lobe control?

  Higher-order functions such as decision-making and problem-solving.
• Why are brain diseases challenging to cure?

  Due to their complexity and difficulty in diagnosing.
• What is a major challenge drugs face when treating brain diseases?

  They struggle to enter the brain due to its complexity.
• What ethical issues arise from testing on animals for brain diseases?

  Unethical testing and lack of informed consent from human patients.
• How do patients with brain damage contribute to medical knowledge?

  They provide insights that benefit the wider population.