Neurones

• What do sensory receptors do in the nervous system?

  They send impulses along sensory neurones to the central nervous system.
• What are neurones specialized for?

  They are specialized cells that carry nervous impulses.
• How many main types of neurones are there?

  There are three main types of neurones.
• What do sensory neurones do?

  Sensory neurones carry impulses from the sensory receptors to the central nervous system.
• What is the function of motor neurones?

  Motor neurones carry impulses from the central nervous system to effector organs.
• Where are relay neurones found?

  Relay neurones are found only in the central nervous system.
• How does the electrical impulse travel in a motor neurone?

  The electrical impulse jumps from one gap in the myelin sheath to the next.
• What does the nerve ending do in a motor neurone?

  The nerve ending transmits the impulse to an effector, such as a muscle or gland.
• What are the functions of the structures in a neurone?

  • Axon: carries impulses away from the cell body
  • Dendrite: receives impulses from other neurones
  • Myelin sheath: a fatty layer that provides electrical insulation around the neurone
• What should you do to compare the roles of sensory, motor, and relay neurones?

  Identify the specific functions of each type of neurone in the nervous system.
• What is a synapse?

  A synapse is the point where two neurones meet, with a small gap between them.
• How is the electrical impulse transmitted across a synapse?

  The impulse is carried by neurotransmitters across the small gap.
• What effect does nicotine have on neurotransmitter production?

  Nicotine leads to the body producing less of the normal neurotransmitter.
• What happens when the body loses function related to neurotransmitters?

  The body tries to regain both function and neurotransmitter levels, often needing nicotine.
• What are the characteristics of reflex arcs?

  • Immediate
  • Involuntary
  • Innate
• Why do reflex arcs provide a fast response?

  They involve only three neurones and do not require processing by the brain.
• What is an example of a reflex that protects us from harm?

  The eye blink reflex protects the eye from approaching objects.
• How does the number of synapses affect response time in reflexes?

  If the impulse had to go to the brain, there would be more synapses, making the response slower.
• What should you include when discussing stem cell treatment for heart disease?

  Include both the potential benefits and problems of the treatment.
• What is the role of embryonic stem cells in heart disease treatment?

  They have been shown to replace several types of damaged heart cells in mice.
• What should be considered when comparing stem cell treatments to drug treatments?

  • Evidence of effectiveness
  • Risks associated with stem cell treatments
  • Benefits of stem cell treatments
  • Comparison of outcomes with drug treatments