astrocyte

Examples of astrocyte in the following topics:

• Glia

  • Astrocytes make contact with both capillaries and neurons in the CNS .
  • Astrocytes also form the blood-brain barrier: a structure that blocks entrance of toxic substances into the brain.
  • Glial cells of the (a) central nervous system include oligodendrocytes, astrocytes, ependymal cells, and microglial cells.
  • Astrocytes provide nutrients to neurons, maintain their extracellular environment, and provide structural support.
  • (a) Astrocytes and (b) oligodendrocytes are glial cells of the central nervous system.

• Neuroglia of the Central Nervous System

  • Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes.
  • Astrocytes are star shaped delicate branching glial cells.
  • These astrocytes cover nearly all the capillaries in the CNS.
  • Oligodendrocytes are cells that have fewer processes compared to astrocytes.

• Types of Nervous Tissue

  • Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes.
  • Astrocytes are shaped like a star and are the most abundant glial cell in the CNS.
  • Astrocytes control the chemical environment around the neurons.
  • They are analogous to the astrocytes in the CNS.

• Neuroglia of the Peripheral Nervous System

  • These resemble the astrocytes of the CNS and assist in regulating the external chemical environment.

• Spinal Cord White Matter

  • Raff et al. discovered that tissue samples originating from the optic nerves of rats contained two morphologically distinct types of astrocytes.
  • "Type 1 astrocytes" had a fibroblasts appearance and resided in both gray matter and white matter.
  • "Type 2 astrocytes" had a neuron-like appearance and resided in white matter alone.

• Blood-Brain Barrier

  • This barrier also includes a thick basement membrane and astrocyte cell projections called astrocytic feet (forming the thin barrier called the glia limitans) that surround the endothelial cells of the BBB, providing biochemical support to those cells.
  • Astrocytes send projections to completely encircle capillaries.

• Clusters of Neuronal Cell Bodies

  • They are thought to have a similar role to astrocytes in the central nervous system (CNS).

• Muscle Tissues and Nervous Tissues

  • Astrocytes regulate the chemical environment of the nerve cell, while oligodendrocytes insulate the axon so the electrical nerve impulse is transferred more efficiently.
  • Also shown are two types of glial cells: astrocytes to regulate the chemical environment of the nerve cell, and oligodendrocytes to insulate the axon so the electrical nerve impulse is transferred more efficiently.

• Capacity of Different Tissues for Repair

  • Astrocytes can be identified in culture because, unlike other mature glia, they express glial fibrillary acidic protein.

• Synaptic Transmission

  • First, reuptake by astrocytes or presynaptic terminal where the neurotransmitter is stored or destroyed by enzymes.