Vertebral Column and Spinal Cord Anatomy

Vocabulary flashcards covering anatomy of the vertebral column, regional vertebral characteristics, spinal ligaments, spinal cord features, nerves, and spinal meninges.

Intervertebral Discs

Thick structures made of aqueous and fibrous portions that separate vertebrae, absorb shock, and permit movement; classified as symphyses (cartilaginous, slightly moveable joints).

Nucleus Pulposus

The inner portion of an intervertebral disc that accommodates compressive loads.

Anulus Fibrosus

The outer ring of an intervertebral disc that accommodates twisting and stretching loads.

Kyphosis

A primary curvature of the vertebral column that is concave anteriorly, bending backwards, and formed during fetal development; excessive curvature leads to hunchback.

Lordosis

A secondary curvature of the vertebral column that is concave posteriorly, bending forward, and formed after the primary curvature.

Pedicles

Short, stout bony processes of the vertebral arch that project posteriorly from the vertebral body to unite with the laminae.

Laminae

Flatter bony plates of the vertebral arch that extend from the pedicles and unite in the posterior midline.

Zygapophysial Joint

A freely moveable, planar multiaxial synovial joint formed by the meeting of superior and inferior articular processes of adjacent vertebrae; also known as a facet joint.

Intervertebral Foramen

An opening formed by vertebral notches and intervertebral discs through which spinal nerves exit the vertebral canal.

Atlas (C1)

The atypical first cervical vertebra that lacks a vertebral body and spinous process (replaced by anterior and posterior tubercles) and features superior articular surfaces to articulate with the skull.

Axis (C2)

The atypical second cervical vertebra that features a superiorly projecting Dens (odontoid process) to allow rotation of the skull.

Median Atlanto-Axial Joint

A uniaxial, freely moveable synovial pivot joint formed between the Dens of C2 (Axis) and C1 (Atlas).

Transverse Foramen

An opening located in the transverse processes of cervical vertebrae (C3-C7) through which the vertebral arteries pass.

Costal Facets

Specialized articular sites (demi-facets on vertebral bodies and transverse costal facets on transverse processes) found on thoracic vertebrae for rib articulation.

Median Sacral Crest

A ridge located on the posterior surface of the sacrum formed by the fused spinous processes of the sacral vertebrae.

Intermediate Sacral Crest

Paired ridges on the posterior sacrum formed by the fusion of sacral articular processes.

Lateral Sacral Crest

Paired ridges on the posterior sacrum formed by the fusion of sacral transverse processes.

Sacral Hiatus

An inferior opening in the sacral canal formed by the absence of the spinous process and laminae of S5.

Anterior Longitudinal Ligament

A ligament located anterior to the vertebral bodies that functions to limit extension of the vertebral column.

Posterior Longitudinal Ligament

A ligament attached to intervertebral discs and located posterior to the vertebral bodies inside the canal that functions to limit flexion.

Ligamentum Flavum

A thick, yellow ligament that unites the laminae of adjacent vertebrae, forms the posterior wall of the vertebral canal, and resists separation during flexion.

Intertransverse Ligament

A ligament connecting adjacent transverse processes that limits lateral flexion (sideways bending) of the vertebral column.

Supraspinous Ligament

A superficial ligament connecting the tips of spinous processes that limits flexion of the vertebral column.

Nuchal Ligament

A ligament extending from the external occipital protuberance to C7 that provides muscle attachment sites to overcome short cervical spinous processes and limits flexion.

Afferent Fibers

Sensory nerve fibers that transmit information towards the Central Nervous System (CNS) from sensory organs and receptors.

Efferent Fibers

Motor nerve fibers that transmit information from the Central Nervous System (CNS) to effector organs such as muscles and glands.

Conus Medullaris

The tapered terminal end of the spinal cord located at the L2 vertebral level.

Cauda Equina

A bundle of loose spinal nerve roots extending inferiorly from the conus medullaris (below L2) resembling a horse's tail.

Filum Terminale

An anchoring filament covered in pia mater (internal to dural sac) and pia + dura mater (external to dural sac) that extends from the tip of the conus medullaris to the coccyx.

Dorsal Horn

The posterior region of spinal cord gray matter consisting of sensory neuron axons and interneurons.

Ventral Horn

The anterior region of spinal cord gray matter consisting mainly of motor neuron cell bodies and interneurons.

Lateral Horn

The intermediate region of spinal cord gray matter found only in the thoracic region, consisting of sympathetic neurons.

Posterior Ramus

A branch of a spinal nerve that carries both sensory and motor information to innervate the deep back muscles and overlying skin.

Anterior Ramus

A large branch of a spinal nerve carrying sensory and motor information that innervates the upper limbs, lower limbs, anterolateral trunk, and skin.

Spinal Meninges

Three membrane layers (dura mater, arachnoid mater, and pia mater) that surround, support, and protect the spinal cord, nerve rootlets, and roots.

Dura Mater

The tough, superficial layer of the spinal meninges that forms the dural sac terminating at S2 and surrounds spinal nerve roots in dural root sheaths.

Arachnoid Mater

The intermediate, web-like layer of the spinal meninges that lines the internal surface of the dura mater.

Pia Mater

The delicate, deep meningeal layer directly adhering to the spinal cord, featuring denticulate ligaments that anchor the spinal cord laterally.

Denticulate Ligaments

Lateral extensions of pia mater that anchor the spinal cord to the arachnoid-lined dura mater.

Subarachnoid Space

The meningeal space located beneath the arachnoid mater that contains Cerebrospinal Fluid (CSF).

Epidural Space

The fat-filled space located superficial to the dura mater within the vertebral canal.