Nerve tissue

• What are the two main components of the nervous system?

  Peripheral nervous system and central nervous system
• What does the central nervous system consist of?

  Brain and spinal cord
• What is a neuron?

  A nerve cell that carries signals
• What do neurons carry?

  Electrical signals or nerve impulses
• What is the function of dendrites in a neuron?

  They receive chemical signals
• What is the myelin sheath?

  Insulation around the axon
• What are Schwann cells?

  Cells that form the myelin sheath
• What are the gaps between Schwann cells called?

  Nodes of Ranvier
• What is the difference between myelinated and non-myelinated neurons?

  Myelinated neurons have a myelin sheath
• How does the diameter of myelinated neurons compare to non-myelinated neurons?

  Myelinated neurons have a larger diameter
• What color are myelinated neurons typically?

  White
• What type of signals do non-myelinated neurons carry?

  Slow impulses for aches and soreness
• What are the two types of nerves?

  Myelinated and non-myelinated
• What are the three types of neurons?

  Sensory, motor, and relay neurons
• What do sensory neurons do?

  Carry signals from receptors to the CNS
• What is the function of motor neurons?

  Carry signals to effectors like muscles
• Where are relay neurons found?

  In the central nervous system
• How do motor neurons connect to effectors?

  They tell muscles to contract
• What are the differences between myelinated and non-myelinated neurons?

  • Myelinated neurons have a myelin sheath
  • Non-myelinated neurons lack a myelin sheath
  • Myelinated neurons have a larger diameter
  • Non-myelinated neurons have a smaller diameter
  • Myelinated neurons are white; non-myelinated are gray
  • Myelinated neurons transmit impulses faster
• What are the three main types of neurons and their functions?

  1. Sensory neurons: Carry signals from receptors to CNS
  2. Motor neurons: Carry signals from CNS to effectors
  3. Relay neurons: Connect sensory and motor neurons in CNS
• What is the role of the central nervous system?

  Processes information and coordinates responses
• What is the function of the axon terminals?

  Join onto the dendrites of other cells
• How do the functions of sensory and motor neurons differ?

  Sensory neurons carry signals to CNS; motor neurons carry signals to effectors
• What are the three types of nerve cells?

  Sensory, relay, and motor neurons
• What is the composition of nervous tissue?

  Specialised cells known as neurons
• What are the two main types of nervous tissue?

  Grey matter and white matter
• What are the two main components of the nervous system?

  Central nervous system and peripheral nervous system
• What is the function of nerve cells?

  To transmit signals around the body
• What is a bundle of nerve cells called?

  A nerve
• What surrounds the axon of a nerve cell?

  Myelin sheath
• What is the role of the myelin sheath?

  To electrically insulate the axon
• What are the main parts of a neuron?

  • Cell body/Soma: contains the nucleus
  • Axon: conducts electric impulses
  • Myelin sheath: electrically insulating layer
  • Dendrite: receives signals from other neurons
  • Schwann cells: produce myelin sheath
  • Node of Ranvier: gaps in myelin sheath
• What do sensory neurons do?

  Receive information from receptor cells
• What types of receptors do sensory neurons use?

  Photoreceptors, chemoreceptors, mechanoreceptors, thermoreceptors
• Where are relay neurons found?

  In the brain and spinal cord
• What do motor neurons do?

  Transmit information from CNS to effectors
• What are effectors?

  Cells or organs that carry out instructions
• What responses do effectors bring about?

  Muscle contraction or hormone release
• What is the difference between myelinated and non-myelinated nerve cells?

  Myelinated transmit impulses faster
• What are the characteristics of myelinated and non-myelinated nerve cells?

  • Myelinated:
  • Transmit impulses very fast
  • 1 - 3 ms
  • Have nodes of Ranvier
  • Non-myelinated:
  • Transmit impulses slower
  • 3 - 120 ms
  • No nodes of Ranvier