radial glia

Examples of radial glia in the following topics:

• Glia

  • The seven types of glia have specific functions that play a role in supporting neuron function.
  • When glia do not function properly, the result can be disastrous; most brain tumors are caused by mutations in glia.
  • There are several different types of glia with different functions .
  • Satellite glia provide nutrients and structural support for neurons in the PNS.
  • Radial glia serve as bridges for developing neurons as they migrate to their end destinations.

• Animal Characterization Based on Body Symmetry

  • Animals can be classified by three types of body plan symmetry: radial symmetry, bilateral symmetry, and asymmetry.
  • Radial symmetry is the arrangement of body parts around a central axis, like rays on a sun or pieces in a pie.
  • Radially symmetrical animals have top and bottom surfaces, but no left and right sides, or front and back.
  • All true animals, except those with radial symmetry, are bilaterally symmetrical.
  • This is termed secondary radial symmetry.

• Body Plans

  • Animal body plans can have varying degrees of symmetry and can be described as asymmetrical, bilateral, or radial.
  • They can be asymmetrical, radial, or bilateral in form .
  • Radial symmetry describes an animal with an up-and-down orientation: any plane cut along its longitudinal axis through the organism produces equal halves, but not a definite right or left side.
  • The sponge is asymmetrical, the sea anemone has radial symmetry, and the goat has bilateral symmetry.

• Neurons and Glial Cells

  • Neurons and glia coordinate actions and transmit signals in the CNS and PNS.
  • The nervous system is made up of neurons, specialized cells that can receive and transmit chemical or electrical signals, and glia, cells that provide support functions for the neurons by playing an information processing role that is complementary to neurons.
  • Glia can be compared to the workers at the electric company who make sure wires go to the right places, maintain the wires, and take down wires that are broken.

• Phylum Echinodermata

  • Echinoderms possess a unique ambulacral or water vascular system, consisting of a central ring canal and radial canals that extend along each arm .
  • The ring canal connects the radial canals (there are five in a pentaradial animal), and the radial canals move water into the ampullae, which have tube feet through which the water moves.
  • The nervous system in these animals is a relatively simple structure with a nerve ring at the center and five radial nerves extending outward along the arms.

• Class Scyphozoa

  • In some species, the digestive system may be further branched into radial canals.

• Rhizaria

  • A second subtype of Rhizaria, the radiolarians, exhibit intricate exteriors of glassy silica with radial or bilateral symmetry .

• Animal Characterization Based on Features of Embryological Development

  • Radially-symmetrical animals are diploblasts, developing two germ layers: an inner layer (endoderm) and an outer layer (ectoderm).
  • Deuterostomes undergo radial cleavage where the cleavage axes are either parallel or perpendicular to the polar axis, resulting in the alignment of the cells between the two poles.

• Constructing an Animal Phylogenetic Tree

  • Eumetazoa are subdivided into radially-symmetrical animals and bilaterally-symmetrical animals and are classified into clade Radiata or Bilateria, respectively.
  • The cnidarians and ctenophores are animal phyla with true radial symmetry.

• Brain: Midbrain and Brain Stem

  • A rare genetic disorder, fatal familial insomnia, causes the degeneration of thalamic neurons and glia.