Chapter 14: Spinal Cord Gross Anatomy

Posterior root ganglion

the cell bodies of these sensory neurons in the posterior root are located here.

Lateral horn

are found in the T1-T12 parts of the spinal cord only; contain the celll bodies of autonomic motor neurons; which innervates cardiac muscle, smooth muscles and glands.

White commissure

connects the anterior funiculi.

Rami communicantes

contains axons associated with the ANS; each set of rami extends between the spinal nerve and ball like structure called the sympathetic trunk ganglion.

Anterior root

contains motor axons only and is formed from the merging of multiple anterior rootlets.

Posterior root

contains sensory axons only and is formed from the merging of multiple posterior rootlets.

Conus medularis

marks the official "end" of the spinal cord proper.

Filum terminale

a thin strand of pia mater that helps anchor the conus medullaris to the coccyx.

Anterior horn

are the left and right anterior masses of the gray matter and primarily houses the cell bodies of somatic motor neurons; which innervate skeletal muscles.

Posterior horn

are the left and right posterior masses of the gray matter; axons of the sensory neurons and the cell bodies of interneurons are located here.

Gray matter

in the spinal cord is centrally located and its shape resembles the letter 'H' or a butterfly.

Gray commissure

is a horizontal bar of gray matter that surrounds a narrow central canal; primarily contains unmyelinated axons and serves as a communication route between the right and left sides of the gray matter.

Nerve plexuses

is a network of interweaving anterior rami of spinal nerves.

Lumbar

is a shorter segment of the spinal cord that contains the neurons for the 5 pairs.

Dermatome

is a specific segment of skin innervated by a single spinal nerve. includes all spinal nerves except for C1.

Cerivcal and lumbosacral enlargement

is an enlarged region of the inferior cervical and mid-lumbar part of the spinal cord

Anterior funiculus

is composed of white matter that occupies the space on each anterior side of the cord between the anterior gray horns and the anterior medican fissure.

White matter

is external to the gray matter.

Cervical Plexuses

is located deep on each side of the neck, immediately lateral to cervical vertebrae.

Coccygeal

is the most inferior part of the spinal cord and contains 1 pair of nerves.

Cervical

is the superior most of the spinal cord. it is continuous with the medulla oblongata. contains neurons whose axons contribute to the 8 pairs.

Lateral funiculus

is the white matter on each lateral side of the spinal cord.

Posterior funiculus

lies between the posterior gray horns on the posterior side of the cord and the posterior median sulcus.

Thoracic

lies inferior to the cervical part; it contains the neurons for the 12 pairs.

Sacral

lies inferior to the lumbar part of the spinal cord and contains neurons for the 5 pairs.

Posterior and anterior ramus

posterior: is the smaller of the two main branches; innervates the deep muscles of the back and the skin of the back. anterior: is the larger of the two main branches; ; which innervates the anterior and lateral portions of the trunk, the upper and lower limbs.

Cauda equine

the rootlets of the more inferior spinal nerves including L2-L5, S1-S5 and Co 1 extend from the conus medullaris; collectively they are called this.