Vertebral Column and Arthrology

Flashcards covering the anatomy, curvatures, atypical vertebrae, ligaments, and joints of the human vertebral column based on the lecture transcript.

Primary curves

The thoracic and sacral curvatures of the spine.

Secondary curves

The cervical and lumbar curvatures of the spine.

$L5$ vertebra

The largest of all movable vertebra which carries the weight of the upper body, has stout transverse processes, and is largely responsible for the lumbosacral angle.

Sacral promontory

The anterior edge of the body of $S1$.

Median sacral crest

The prominent midline ridge on the dorsal surface of the sacrum representing remnant spinous processes (except $S5$).

Intermediate sacral crests

The ridges on the dorsal surface of the sacrum representing remnant articular processes.

Lateral sacral crests

The ridges on the dorsal surface of the sacrum representing remnant transverse processes.

Sacral hiatus

An opening resulting from the absence of the $S5$ spinous process and laminae, containing fatty connective tissue, the filum terminale, and the $S5$ spinal and coccygeal nerves.

Sacral cornua

The inferior articular processes of $S5$ which serve as palpation landmarks.

Atlas ($C1$)

A ring-shaped, atypical cervical vertebra with no spinous process or body that supports the skull; it features anterior and posterior arches and kidney-shaped superior articular facets.

Axis ($C2$)

The strongest cervical vertebra, characterized by a tooth-like dens (odontoid process) and a large bifid spinous process, which is the first palpable spinous process.

Dens (odontoid process)

A blunt tooth-like projection from the body of $C2$ that serves as a pivot for the rotation of $C1$.

Anterior Longitudinal Ligament (ALL)

A strong ligament connecting the anterior aspects of vertebral bodies and discs from the sacrum to $C1$ and the occipital bone; it maintains stability and prevents hyperextension.

Posterior Longitudinal Ligament (PLL)

A ligament running along the posterior aspect of vertebral bodies within the vertebral canal from $C2$ to the sacrum; it helps prevent hyperflexion and posterior protrusion of the nucleus pulposus.

Anulus Fibrosus

The outer fibrous rim of an intervertebral disc composed of concentric lamellae of fibrocartilage arranged obliquely for strength.

Nucleus Pulposus

The elastic, avascular central core of the intervertebral disc with high $H_2O$ content that acts as a shock absorber and semifluid ball-bearing.

Zygapophyseal joints

Synovial facet joints located between the inferior articular process of a superior vertebra and the superior articular process of an inferior vertebra.

Ligamenta Flava

Broad elastic "yellow ligaments" that extend between adjacent laminae, helping to preserve normal curvatures and aid in straightening the column after flexion.

Ligamentum nuchae

A wide, thick band of fibroelastic connective tissue at the nape of the neck and base of the skull where interspinous and supraspinous ligaments join superiorly.

Atlanto-occipital joint

A condyloid synovial joint between $C1$ and the occipital condyles that permits head nodding (flexion/extension) and sideways tilting.

Transverse ligament of the atlas

A strong band extending between the lateral masses of $C1$ that holds the dens of $C2$ against the anterior arch of $C1$, forming the posterior wall of the socket for the dens.

Cruciform ligament

A cross-shaped structure formed by the transverse ligament of the atlas and superior/inferior longitudinal bands running to the occiput and the body of $C2$.

Alar ligaments

Ligaments extending from the sides of the dens to the lateral margins of the foramen magnum that check rotation and side-to-side movements of the head.

Tectorial membrane

The superior continuation of the Posterior Longitudinal Ligament ($PLL$) that runs from the body of $C1$ to the internal surface of the occipital bone.

Basivertebral veins

Veins that course through and drain the vertebral bodies.