PHA618 nervous system

• Neurons and neuroglia


  Two types of nervous tissue
• Neurons (nerve cells)


  The working units of the nervous system
• Neurons (nerve cells)


  Generates and transmits nerve impulses
• Neuroglia


  Type of connective tissue formed by glial cells
• Neuroglia


  Support the neurons
• Nerves


  Bundle of axons bound together
• Cell body and process


  Each neuron consists of ___ and ___
• 1 axon and usually many dendrites


  Processes of a neuron
• Oxygen and glucose


  Neurons need a continuous supply of ___ and ___ for survival
• False


  True or false: neurons can divide
• Action potentials


  Electrical impulses that neurons generate and transmit
• Relay stations


  Where are neurons passed on and sometimes redirected to?
• True


  True or false: Some neurons initiate action potentials while others act as 'relay stations
• Outside and inside the body


  Action potentials can be initiated in response to stimuli from ___ and ___
• Touch and light waves


  Examples of stimuli from outside the body
• Change in the concentration of carbon dioxide in the blood alters respiration; a thought may result in voluntary movement

  Examples of stimuli from inside the body
• Cell body


  Which part of a neuron: forms the grey matter of the nervous system
• Cell body


  Which part of a neuron: found in the periphery of the brain and the center of the spinal cord
• Nuclei


  Groups of cell bodies (in the CNS)
• Ganglia


  Groups of cell bodies (in the PNS)
• Axons and dendrites


  Which parts of the neuron: extensions of cell bodies and form the nervous system's white matter.
• Axons


  Which part of the neuron: found deep in the brain and at the periphery of the spinal cord
• Tracts


  What do u call a group of axons
• True


  True or false: Each nerve cell has only one axon
• Chemoreceptors in the brain stem


  Detects pH changes in the blood
• Axon hillock


  Tapered area of the cell body
• In the axon hillock


  The axon begins where?
• Axons


  Which part of the neuron: carry impulses AWAY from the cell body
• Dendrites


  WHich is shorter: axons or dendrites
• Myelinated and unmyelated


  2 types of axons
• Myelin sheath


  Responsible for "saltatory conduction" action potentials
• Saltatory conduction


  The presence of myelin sheath is responsible for ___
• Unmyelinated fibers


  Myelinated or unmyelinated: slower conduction of action potentials
• Myelinated fibers


  Myelinated or unmyelinated: faster conduction of action potentials
• Myelinated


  Myelinated or unmyelinated: white matter
• Unmyelinated


  Myelinated or unmyelinated: gray matter
• Myelinated


  Myelinated or unmyelinated: For insulation
• Nodes of ranvier


  Spaces between myelinated neurons
• Dendrites


  Which part of the neuron: short processes that receive and carry incoming action potentials and DIRECT them towards cell bodies
• Dendrites


  Which part of the neuron: same structure as the axons, but are usually shorter and more branching