Spinal Cord
The bundle of nervous tissue that runs from the brain to the first to third lumbar vertebrae and provides a conduction pathway to and from the brain.
Conus Medullaris
The terminal end of the spinal cord.
Occurs near lumbar vertebral levels 1 (L1) and 2 (L2).
Filum Terminale
Continuation of the conus medullaris and is the thin cord-like structure that extends down to the end of the spinal canal.
Cauda Equina
The roots of the spinal nerves controlling movement and sensation in the legs. These nerve roots are located in the lower spine.
Gray Matter
Cross section of the spinal cord; looks like a butterfly or "H"
Posterior Horns
Dorsal projections of the gray matter.
Anterior Horns
Ventral projections of the grey matter.
Lateral Horns
Lateral outpocketing of grey matter that can be observed in the thoracic and lumbar regions of the spinal cord.
Gray Commissure
Central area of grey matter connecting the two ventral regions.
Central Canal
Surrounded by the gray commissure, contains CSF.
Dorsal Root
Point of entry of interneurons and sensory fibers into the spinal cord from the body.
Dorsal Root Ganglion
Peripheral collection of cell bodies of first-order afferent neurons whose central axons enter the spinal cord.
Ventral Root
Point of exit for axons of motor neurons of the somatic nervous system, so their signal can be transmitted into adjacent spinal nerves.
White Matter
Surrounds the gray matter and is bisected by fissures.
Anterior Median Fissure
More open fissure
Posterior Median Sulcus
More shallow.
Posterior Median Septum
A sheet of glial tissue in the midsagittal plane of the spinal cord that extends from the posterior median sulcus toward the gray commissure and that partitions the posterior part of the spinal cord into right and left halves
White Column (Dorsal Funiculus)
Dorsal section of white matter
White Column (Lateral Funiculus)
Lateral section of white matter
White Column (Ventral Funiculus)
Ventral section of white matter
Tracts
Collection of axons that conduct sensory inpulses to the brain.
Spinal Nerves Mixed
All spinal nerves are mixed nerves (carry signals to and from the spinal cord)
Dorsal Rami
The posterior branches of the spinal nerves. (Smaller than ventral rami.)
Ventral Rami
The anterior branches of the spinal nerves. (Larger than dorsal rami)
Nerve Plexuses
Interlacing nerve networks that occur in the cervical, brachial, lumbar, and sacral regions and primarily serve the limbs.
Cervical Plexus
Phrenic Nerve
Brachial Plexus
Axillary Nerve
Radial Nerve
Medial Nerve
Ulnar Nerve
Lumbar Plexus
Femoral Nerve
Sacral Plexus
Sciatic Nerve (Largest)
Common Fibular Nerve
Tibial Nerve

What is A?
White Matter/Column

What is B?
Dorsal Funiculus

What is C?
Ventral Funiculus

What is D?
Lateral Funiculus

What is E?
Dorsal Median Sulcus

What is F?
Gray Commissure

What is G?
Dorsal Horn

What is H?
Ventral Horn

What is I?
Lateral Horn

What is J?
Gray Matter

What is K?
Central Canal

What is L?
Ventral Medium Fissure

What is M?
Dorsal Ganglia Root

What is N?
Spinal Nerve

What is O?
Dorsal Root

What is P?
Ventral Root