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Peripheral Nervous System - Histology (view source)
Revision as of 17:41, 23 October 2011
, 17:41, 23 October 2011→Histology
==Histology==
==Histology==
===Myelinated Nerves===
===Myelinated Nerves Cross-section===
[[Image:WIKIVETmyleinatednerveinsmallfibre.jpg|thumb|right|200px|Myelinated Nerve in Small Fibre - Copyright John Bredl]]
[[Image:WIKIVETmyleinatednerveinsmallfibre.jpg|thumb|right|200px|Myelinated Nerve in Small Fibre - Copyright John Bredl]]
This image shows a cross-sectional histology of a myelinated nerve fibre. The section clearly shows numerous bundles of nerve fibres which are slightly out of focus, but appear as the globular contents of the nerve.
This image shows a cross-sectional histology of a myelinated nerve fibre. The section clearly shows numerous bundles of nerve fibres which are slightly out of focus, but appear as the globular contents of the nerve.
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The nerve as a whole is surrounded by a dense layer of connective tissue; the epineurium. This layer often contains visible blood vessels and it is likely that there are two such vessels found to the left and upper-left of the nerve. Fat cells (adipose tissue) are also found around the epineurium, although none are clearly visible in this image.
The nerve as a whole is surrounded by a dense layer of connective tissue; the epineurium. This layer often contains visible blood vessels and it is likely that there are two such vessels found to the left and upper-left of the nerve. Fat cells (adipose tissue) are also found around the epineurium, although none are clearly visible in this image.
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===Myelinated Nerve Cross-section (with lipid stain)===
===Myelinated Nerve (with lipid stain)===
[[Image:WIKIVETmyeinatednerveinsmallfibrelipdstained.jpg|thumb|right|150px|Myelinated Nerve in Small Fibre, Lipid Stained - Copyright John Bredl]]
[[Image:WIKIVETmyeinatednerveinsmallfibrelipdstained.jpg|thumb|right|150px|Myelinated Nerve in Small Fibre, Lipid Stained - Copyright John Bredl]]
A lipid stain highlights aspects within the histology that contain lipid. In this case the main lipid bearing tissue within a nerve is the fat contained within the myelin sheath, or Schwann cells. In comparison with the image above, this image is taken at a higher magnification and shows the bundles of nerve fibres in more detail.
A lipid stain highlights aspects within the histology that contain lipid. In this case the main lipid bearing tissue within a nerve is the fat contained within the myelin sheath, or Schwann cells. In comparison with the image above, this image is taken at a higher magnification and shows the bundles of nerve fibres in more detail.
Given the lipid stain, it is possible to distinguish the myelinated nerves from the unmyelinated nerves within each bundle. Therefore a large proportion of the nerves are myelinated within each bundle. These myleinated nerves appear at this magnification with a charactristic ''donut'' shape which represents the axon in the centre (which contains no lipid) and the surrounding Scwann cell (containing lipid).
Given the lipid stain, it is possible to distinguish the myelinated nerves from the unmyelinated nerves within each bundle. Therefore a large proportion of the nerves are myelinated within each bundle. These myleinated nerves appear at this magnification with a charactristic ''donut'' shape which represents the axon in the centre (which contains no lipid) and the surrounding Scwann cell (containing lipid).
===Myelinated Nerve Longitudinal section===
===Myelinated Nerve (longitudinal section)===
[[Image:WIKIVETmyelinatednervesinsmallfibreinlongittudinlsection.jpg|thumb|right|150px|Myelinated Nerve in Small Fibre, in Longitudinal Section - Copyright John Bredl]]
[[Image:WIKIVETmyelinatednervesinsmallfibreinlongittudinlsection.jpg|thumb|right|150px|Myelinated Nerve in Small Fibre, in Longitudinal Section - Copyright John Bredl]]