Neuroscience: Functional Anatomy of the Spinal Cord

A set of vocabulary flashcards covering the gross anatomy, ligaments, and internal nuclei of the vertebral column and spinal cord based on the PT 105 Neuroscience laboratory activity.

Vertebral Column

A flexible structure composed of $33$ vertebrae, including $7$ cervical, $12$ thoracic, $5$ lumbar, $5$ sacral, and $4$ coccygeal segments.

Intervertebral Discs

Fibrocartilage pads that act as shock absorbers and provide cushioning, forming approximately one-fourth the length of the column.

Anulus Fibrosus

The tough outer ring of fibrocartilage that anchors the intervertebral disc to the vertebrae.

Nucleus Pulposus

The gelatinous, semifluid center of the intervertebral disc that allows vertebrae to rock back and forth.

Herniation

The rupture of the anulus fibrosus, allowing the nucleus pulposus to protrude and compress spinal nerves.

Vertebral Foramen

The protective canal for the spinal cord formed by the anterior body and posterior vertebral arch.

Intervertebral Foramina

Gaps formed by the alignment of vertebral notches on stacked pedicles that serve as exit points for spinal nerves.

Ligamentum Flavum

A ligament that connects the laminae of adjacent vertebrae.

Ligamentum Nuchae

A strong thickening of the supraspinous and interspinous ligaments located in the cervical region.

Foramen Magnum

The location where the spinal cord begins as a continuation of the medulla oblongata.

Conus Medullaris

The tapered, cone-like physical termination of the spinal cord.

Filum Terminale

A thread of pia mater that extends from the conus medullaris to anchor the spinal cord to the coccyx.

Subarachnoid Space

The area surrounding the spinal cord that contains cerebrospinal fluid (CSF) for cushioning.

Alpha Efferents

Large multipolar neurons in the anterior gray column that trigger the contraction of skeletal muscles.

Gamma Efferents

Small multipolar neurons in the anterior gray column that innervate intrafusal muscle fibers in muscle spindles.

Phrenic Nucleus

A specialized group of neurons located in segments $C3$-$C5$ vital for diaphragm control and breathing.

Substantia Gelatinosa

A nucleus at the apex of the posterior horn that acts as a gatekeeper for pain, temperature, and touch.

Nucleus Proprius

The largest group in the posterior horn, responsible for processing proprioception, vibration, and two-point discrimination.

Nucleus Dorsalis (Clarke’s Column)

Found from $C8$ to $L3$/$L4$, this nucleus processes unconscious proprioception from muscle and tendon spindles.

Intermediolateral Group

Part of the sympathetic division located from $T1$ to $L2$ or $L3$ that initiates the ‘fight or flight’ response.

Gray Commissure

The horizontal bridge of gray matter connecting the left and right sides of the spinal cord containing the central canal.

Terminal Ventricle

The bulb-like widenening of the central canal located within the conus medullaris.

Ependyma

The layer of ciliated columnar epithelial cells that lines the central canal.

Funiculi

The three primary territories of white matter on each side of the spinal cord: anterior, lateral, and posterior.

Ascending Tracts

Nerve pathways within the white matter that relay sensory information upward to the brain.

Descending Tracts

Nerve pathways within the white matter that transmit motor instructions from the brain to the body.