lecture 7

Cards (21)

  • Neurons
    Communication with other neurons, receive, integrate and transmit electrochemical signals
  • Types of neurons
    • Motor neurons
    • Sensory neurons
  • Glia cells

    Provide structural support and insulation for neurons
  • Types of glia cells
    • Astrocytes
    • Microglia
    • Oligodendrocytes
  • Somatosensory system

    Body's communication network: information processing and transportation
  • Neuron
    • Soma: cell body, with a nucleus which provides energy
    • Dendrites: feeler-like structures to receive information
    • Axon: long, thin fibre that transmits signals away from soma
    • Axon terminal: transmits signals to dendrites of another cell
  • Basic flow of information in a neuron
    Dendrite -> soma -> axon -> to dendrites of another neuron / to effector site
  • Structures on the axon
    • Myelin sheath: wrapped around axon, speeds up firing of neuron
    • Nodes of Ranvier: small gaps on axon with no myelin sheath
  • Motor neurons
    • Soma are in spinal cord, receives signals from other neurons, conducts impulses along axon to axon terminals to a muscle (effector site)
  • Sensory neurons
    • Specialized to be highly sensitive to a particular type of stimulation, dendrites attached to a sensory ending, example: skin
  • Reflex arc is a neural pathway
  • Glia cells

    • Cells that support neurons, found in CNS and PNS
  • Astrocytes
    • Create blood-brain barrier, can help heal brain damage
  • Neurons in the brain generally do not regenerate, so the blood-brain barrier has to block incoming viruses, bacteria, or other harmful material from entering the brain
  • Microglia
    • Functions: clean up dead cells and prevent infection in the brain, immune defence in the nervous system, can become damaged by HIV
  • Oligodendrocytes
    • Provide myelin to speed up transmission of neurons, process is myelination, also involved in maintenance and repair of myelin, only in CNS (in PNS: Schwann Cells)
  • Somatosensory system

    Relays information from skin, limbs, joints and processes it in the brain, contains cutaneous mechanoreceptors that translate mechanical pressure from skin into neural signals
  • Structures on nerve endings that allow us to sense the world (mechanoreceptors)

    • Meissner's corpuscles
    • Pacinian corpuscles
    • Merkel's discs
  • Meissner's corpuscles
    • Sensitive to touch, located near surface of skin, concentrated in sensitive areas like fingers and hairless skin
  • Pacinian corpuscles
    • Sensitive to vibration and pressure, located deep in skin, joints, ligaments, made up of layers of tissue around a free nerve ending
  • Merkel's discs
    • Sensitive to pressure, position of touch, light touch, sustained response to pressure, "slowly adapting", located near surface of skin