Anatomy of the Back and Vertebral Column

A set of vocabulary flashcards covering the anatomical terms, structural components, embryological developments, and clinical conditions of the back and spinal cord.

Vertebral Canal

The continuous passageway formed by the aligned vertebral foramina in an articulated skeleton that conveys the spinal cord and its coverings.

Atlas

The first cervical vertebra (C1), lacking a body and spinous process, which features lateral masses with superior articular surfaces for the occipital condyles and inferior surfaces for articulation with C2.

Axis

The second cervical vertebra (C2), characterized by a peglike odontoid process (dens) projecting upward from the superior surface of its body.

Vertebra Prominens

The seventh cervical vertebra (C7), so named because it possesses the longest non-bifid spinous process.

Sacral Promontory

The anterior and upper margin of the first sacral vertebra that bulges forward as the posterior margin of the pelvic inlet.

Primary Curvatures

The thoracic and sacrococcygeal curves of the vertebral column that retain their initial prenatal anterior concavities.

Secondary Curvatures

The cervical and lumbar curves of the vertebral column that form postnatally and feature posterior concavities.

Kyphosis

A severe exaggeration in the thoracic curvature of the vertebral column resulting from structural changes in the vertebral bodies or intervertebral discs.

Lordosis

An exaggeration of either of the secondary vertebral curvatures, most commonly appearing as an accented lumbar curve.

Scoliosis

A lateral deviation of the vertebral column, usually including malrotation, most commonly found in the thoracic region.

Sclerotome

The ventromedial part of an embryonic somite whose cells divide and migrate medially during the 4th week to surround the notochord and form the mesenchymal vertebral body.

Spina Bifida

A developmental defect caused by failure of the mesenchymal vertebral arches to fuse in the posterior midline, leaving a gap in the vertebral arch.

Anulus Fibrosus

The peripheral part of an intervertebral disc composed of approximately 14 concentric layers (lamellae) of fibrocartilage.

Nucleus Pulposus

The central, ovoid mass of an intervertebral disc derived from the embryonic notochord, consisting of a mucopolysaccharide gel with high water content.

Ligamentum Nuchae

A strong cervical thickening of the supraspinous and interspinous ligaments extending from the C7 spinous process to the external occipital protuberance.

Auscultatory Triangle

A back region bounded by the latissimus dorsi, trapezius, and rhomboid major where breath sounds are easily heard due to the lack of covering muscles.

Lumbar Triangle

An anatomical site bounded by the latissimus dorsi, the posterior border of the external abdominal oblique muscle, and the iliac crest where pus or a lumbar hernia may emerge.

Suboccipital Triangle

A space bounded by the rectus capitis posterior major, obliquus capitis inferior, and obliquus capitis superior containing the suboccipital nerve and vertebral artery.

Thoracolumbar Fascia

The deep fascia in the lumbar region between the iliac crest and 12th rib that splits into three lamellae to enclose the deep back muscles and quadratus lumborum.

Conus Medullaris

The tapered inferior end of the spinal cord, located at approximately the L1 vertebral level in adults.

Filum Terminale

A slender prolongation of pia mater descending from the apex of the conus medullaris to attach to the back of the coccyx.

Cauda Equina

The long vertical bundle of lumbar, sacral, and coccygeal spinal nerve roots that surrounds the filum terminale below the conus medullaris.

Lumbar Cistern

The enlarged subarachnoid space inferior to the conus medullaris containing the cauda equina floating in cerebrospinal fluid.

Ligamentum Denticulatum

A serrated lateral extension of the pia mater off each side of the spinal cord that attaches to the dura-arachnoid sac to stabilize the cord.

Jefferson's Fracture

A vertical compression fracture that disrupts the ring of the atlas (C1) and displaces its lateral masses laterally.

Hangman's Fracture

A fracture involving the pedicles of the axis (C2) caused by severe overextension injury of the neck.

Spondylolisthesis

A condition in which the body of a lower lumbar vertebra (usually L5) slips forward on the body of the vertebra below or upon the sacrum.

Sciatica

Pain felt down the back and lateral side of the leg radiating to the sole of the foot, commonly caused by compression of L5 or S1 nerve roots.

Epimere

The smaller posterior portion of a developmental myotome that forms in the back, is innervated by the posterior rami of spinal nerves, and gives rise to intrinsic back muscles.

Hypomere

The larger anterolateral portion of a developmental myotome supplied by anterior rami of spinal nerves, giving rise to extrinsic back muscles.