Neuraglia

The central and peripheral nervous systems have their respective neuralgia

Neuroglia in the CNS

There are four types of neuroglia found within the central nervous system:

• Astrocytes – maintain the blood brain barrier and preserve the chemical environment by recycling ions and neurotransmitters
• Oligodendrocytes – myelinate axons in the central nervous system and provide an overall structural framework
• Ependymal cells – line ventricles (brain) and central canal (spine) and are involved in the production of cerebrospinal fluid
• Microglia – remove cell debris, wastes and pathogens via phagocytosis

Neuroglia in the PNS

There are two types of neuroglia found within the peripheral nervous system:

• Schwann cells – myelinate axons in the peripheral nervous system
• Satellite cells – regulate nutrient and neurotransmitter levels around neurons in ganglia

Types of Neuroglia

 

 

The majority are glia, which form the structural framework of the nervous system and They provide functional support for the neurons.

• These include astrocytes, oligodendrocytes, microglia, schwann cells. .

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  Oligodendrocytes produce myelin in the CNS, while Schwann cells produce myelin in the PNS.

• Microglia arise from macrophages and phagocytose debris following neuronal injury or death.

• Astrocytes provide structural support for the neurons in the CNS, insulate and separate neurons from one another, and help to regulate the potassium ion concentration in the extracellular space around neurons.

• Tight junctions between the foot processes of astrocytes and the endothelial membrane of the vessels help to maintain the BBB.

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• Oligodendrocytes, found only in the central nervous system, and Schwann cells, found only in the peripheral nervous system, are glial cells that perform similar functions. They produce myelin, a phospholipid bilayer which insulates the axon and allows for faster propagation of an action potential, commonly referred to as saltatory conduction.

   

  One oligodendrocyte can provide myelin sheaths for many axons, but a Schwann cell provides myelin for just one axon.

  Nervous tissue contains little extracellular material.

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  Microglia, the phagocytes of the nervous system, are mobilized by insults to the CNS and remove debris following neuronal injury or death. They arise from macrophages outside of the nervous system and are physiologically unrelated to other glial cells.

• Astrocytes, the most numerous type of glial cell, are star-shaped cells that fill the interneuronal space in the CNS. They provide structural support for the neurons in the CNS, insulate and separate neurons from one another, and help to regulate the potassium ion concentration in the extracellular space around neurons.

• The most important structure creating the blood-brain barrier is the specialized tight junction of the endothelial cells.Tight junctions between the foot processes of astrocytes and the endothelial membranes of blood vessels help to maintain the blood-brain barrier, an almost impermeable lining of the brain’s capillaries and venules that prevents certain toxic substances in the blood from entering the brain. This protective mechanism can present an obstacle for efficacious delivery of therapeutic agents to the CNS.

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• Glial cells support neurons and form the structural framework for the nervous system.

  neuroglia function to provide nourishment

• Oligodendrocytes produce myelin in the CNS, while Schwann cells produce myelin in the PNS.

• Microglia arise from macrophages and phagocytose debris following neuronal injury or death.

• Astrocytes provide structural support for the neurons in the CNS, insulate and separate neurons from one another, and help to regulate the potassium ion concentration in the extracellular space around neurons.

Tight junctions between the foot processes of astrocytes and the endothelial membranes of blood vessels help to maintain the blood-brain barrier, an almost impermeable lining of the brain’s capillaries and venules that prevents certain toxic substances in the blood from entering the brain. This protective mechanism can present an obstacle for efficacious delivery of therapeutic agents to the CNS.