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Spinal Cord Segments – Cross-sectional Anatomy

Spinal Cord Segments – Cross-sectional Anatomy

Author: Scott A. Sheffield MS

Last update: Oct 24th, 2022

The spinal cord is made up of 31 segments.

Cross section of the spinal cord showing the L1 and L2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Each segment gives rise to a pair of spinal nerves.

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Spinal segments (L2,L2) showing the spinal nerve

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In cross-section (c.s.), the segments appear to be divided into two zones.
The outer zone contains many myelinated axons that run up and down the spinal cord.

Understand all things spinal cord, white and grey matter with this step-by-step interactive quiz and worksheet guide.

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Spinal segments (L2,L2) showing histology image of the Myelinated axons of the white matter

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Myelin is mostly lipid and light in color. Therefore, this zone is referred to as white matter.

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Spinal segments (L2,L2) showing the white matter of the spinal cord

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The inner zone is shaped somewhat like a butterfly (or “H”) and contains many cell bodies and dendrites.

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

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This zone lacks myelin and is darker in color. It is therefore referred to as gray matter.

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Spinal segments (L2,L2) showing the gray matter of the spinal cord

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Almost dividing the spinal cord in half are two longitudinal grooves.
The narrow indentation that partitions the back surface is known as the dorsal median sulcus (or posterior median sulcus) and the broader groove that partitions the front surface is called the ventral median fissure (or anterior median fissure).

Cross section of the spinal cord showing 2 lumbar segments, gray matter, white matter and spinal nerve

Spinal segments (L2,L2) showing Dorsal median sulcus of the spinal cord

Spinal segments (L2,L2) showing the Ventral median fissure of the spinal cord

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Microscope image of the spinal cord segment [ Show / Hide ]

Microscope image of the spinal cord segment showing (white matter, gray matter,

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Overview:

Image showing the parts of the spinal cord segment without answers

Image showing the parts of the spinal cord segment with answers, Dorsal median sulcus, Gray and White matters, Spinal nerve and Ventral median fissure

Swipe to show/hide the answers

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