Page 89 - Headlines Histology2024_Neat

• They are so named because they are fairly small with tree-like processes.
• In H&E sections, the cell has a small, spherical densely stained nucleus and a

small number of thin, short-branched processes.
• The cytoplasm is rich in rER, mitochondria and microtubules.
Functions

• Formation of myelin sheathes around the CNS axons.
• A single cell may be responsible for the myelination of up to 50 nerve

fibers.
• They are usually found in rows between the myelinated fibers of the white

matter.
• They surround neuron cell bodies in the gray matter.
Astrocytes (Astron, star)

• They are so named because they possess radiating processes and have a star-
like appearance. Two types are recognized:

Protoplasmic astrocytes
• They are the most numerous glial cells in gray matter.
• They have long, thick, highly branched processes that occupy most of the
interneuronal spaces.
• The cytoplasm is rich in bundles of microtubules.
• Many of the astrocyte processes terminate as end feet or perivascular feet upon
the blood capillaries. Other processes terminate close to the non-synaptic
regions of neurons.

Fibrous astrocytes
• They predominate in white matter. They have long, thin moderately branched
processes.
• The cytoplasm is rich in microfilaments.
Functions

• Provide structural support for neurons.

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