Satellite glial cells

Examples of Satellite glial cells in the following topics:

• Clusters of Neuronal Cell Bodies

  • Ganglia are composed mainly of neuron cell bodies (somata) and dendritic structures.
  • Satellite glial cells are a type of glial cell that line the exterior surface of neurons in the peripheral nervous system (PNS) .
  • Satellite glial cells (SGCs) also surround neuron cell bodies within ganglia.
  • Satellite cells also act as protective, cushioning cells.
  • Satellite glial cells are expressed throughout the sympathetic and parasympathetic ganglia in their respective nervous system divisions.

• Glia

  • While glia (or glial cells) are often thought of as the supporting cast of the nervous system, the number of glial cells in the brain actually outnumbers the number of neurons by a factor of ten.
  • Glial cells support neurons and maintain their environment.
  • Glial cells of the (a) central nervous system include oligodendrocytes, astrocytes, ependymal cells, and microglial cells.
  • Glial cells of the (b) peripheral nervous system include Schwann cells, which form the myelin sheath, and satellite cells, which provide nutrients and structural support to neurons.
  • (a) Astrocytes and (b) oligodendrocytes are glial cells of the central nervous system.

• Types of Nervous Tissue

  • Neuroglia are also called "glial cells."
  • These glial cells are involved in many specialized functions apart from support of the neurons.
  • In the PNS, satellite cells and Schwann cells are the two kinds of neuroglia.
  • Astrocytes are shaped like a star and are the most abundant glial cell in the CNS.
  • Satellite cells surround neuron cell bodies in the peripheral nervous system (PNS).

• Capacity of Different Tissues for Repair

  • Neuroregeneration refers to the regrowth or repair of nervous tissue, cells, or cell products.
  • It is limited by the inhibitory influences of the glial and extracellular environment.
  • In undamaged muscle, the majority of satellite cells are quiescent; they neither differentiate nor undergo cell division.
  • In response to mechanical strain, satellite cells become activated.
  • Activated satellite cells initially proliferate as skeletal myoblasts before undergoing myogenic differentiation.

• Neuroglia of the Peripheral Nervous System

  • The two kinds of glia cells in the PNS, schwann cells and satellite cells, each have unique functions.
  • The PNS has two kinds of neuroglia: schwann cells and satellite cells.
  • Schwann cells provide myelination to peripheral neurons.
  • Satellite cells are small glia that surround neurons' sensory ganglia in the ANS.
  • PNS satellite glia are very sensitive to injury and may exacerbate pathological pain.

• Defective Viruses

  • Not all viruses can reproduce in a host cell by themselves.
  • Satellites depend on co-infection of a host cell with a helper virus for productive multiplication.
  • When a satellite subviral agent encodes the coat protein in which it is encapsulated, it is then called a satellite virus.
  • Satellite viral particles should not be confused with satellite DNA.
  • These viruses that are dependent on the presence of other virus species in the host cell are called satellites.

• Muscle Tissues and Nervous Tissues

  • A nerve consists of a neuron and glial cells.
  • Glial cells support the neurons.
  • Other glial cells support the nutritional and waste requirements of the neuron.
  • Some of the glial cells are phagocytic, removing debris or damaged cells from the tissue.
  • 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.

• 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.
  • Ependymal cells are another glial subtype that line the ventricles of the CNS.
  • Oligodendrocytes are cells that have fewer processes compared to astrocytes.
  • Oligodendrocytes form the electrical insulation around the axons of CNS nerve cells.

• Muscle Development

  • Myoblasts that do not form muscle fibers dedifferentiate back into satellite (myosatellite) cells .
  • Satellite cells are able to differentiate and fuse to augment existing muscle fibers and to form new ones.
  • In undamaged muscle, the majority of satellite cells are quiescent; they neither differentiate nor undergo cell division.
  • In response to mechanical strain, satellite cells become activated and initially proliferate as skeletal myoblasts before undergoing myogenic differentiation.
  • Satellite cells are located between the basement membrane and sarcolemma (cell membrane) of individual muscle fibers.

• Cellular Differentiation

  • Three basic categories of cells make up the mammalian body: germ cells, somatic cells, and stem cells.
  • Hematopoietic stem cells (adult stem cells) from the bone marrow that give rise to red blood cells, white blood cells, and platelets
  • Mesenchymal stem cells (adult stem cells) from the bone marrow that give rise to stromal cells, fat cells, and types of bone cells;
  • Epithelial stem cells (progenitor cells) that give rise to the various types of skin cells
  • Muscle satellite cells (progenitor cells) that contribute to differentiated muscle tissue