Principles of Human Anatomy - Back and Spinal Cord Anatomy

Vocabulary practice flashcards covering key anatomical structures, spinal features, musculature, innervation, and clinical concepts from the Human Anatomy back region lecture.

Dermatome

A band-like area of skin receiving sensory innervation from a single pair of spinal nerves originating from a single spinal cord segment.

Intervertebral (IV) Foramina

Openings located in the lateral wall of the vertebral canal between adjacent vertebrae through which spinal nerves exit.

Vertebra Prominens

The seventh cervical vertebra ($C7$), characterized by a particularly long spinous process that is easily felt at the base of the neck.

Anulus Fibrosus

The outer fibrous ring of an intervertebral disc composed of concentric lamellae of fibrocartilage, which is thinner posteriorly.

Nucleus Pulposus

The gelatinous central mass of an intervertebral disc that acts as a cushion and shock-absorbing fulcrum during spine movement.

Primary Curvatures

Thoracic and sacral curvatures of the adult vertebral column that develop during fetal life and maintain a concave anterior orientation ($1^\circ$ curvatures).

Secondary Curvatures

Cervical and lumbar curvatures of the vertebral column that develop during infancy and childhood, characterized by an anteriorly convex orientation ($2^\circ$ curvatures).

Kyphosis

An abnormal increase in the thoracic curvature of the vertebral column, often resulting in an exaggerated humpback appearance.

Lordosis

An abnormal anterior tilting of the pelvis accompanied by increased extension of the lumbar vertebrae, causing an exaggerated hollow back.

Scoliosis

An abnormal lateral curvature of the vertebral column accompanied by vertebral rotation.

Osteophytes

Bony spurs that form around the margins of vertebral bodies and articular processes as a result of aging or mechanical stress.

Median Atlanto-Axial Joint

A pivot joint formed by the anterior arch and transverse ligament of the atlas ($C1$) enclosing the dens of the axis ($C2$), enabling head rotation.

Splenius Capitis

A superficial intrinsic back muscle that originates from the nuchal ligament and spinous processes of $C7-T6$ and inserts on the mastoid process and superior nuchal line.

Erector Spinae

The intermediate layer of intrinsic back muscles arranged in three vertical columns (iliocostalis, longissimus, and spinalis) that act bilaterally to extend the spine.

Transversospinalis Muscle Group

The deep layer of intrinsic back muscles comprising semispinalis, multifidus, and rotatores, running obliquely from transverse processes to superior spinous processes.

Suboccipital Nerve

The posterior ramus of spinal nerve $C1$, running between the cranium and $C1$ vertebra to innervate the muscles of the suboccipital triangle.

Greater Occipital Nerve

The posterior ramus of spinal nerve $C2$, which emerges inferior to obliquus capitis inferior and ascends to supply the skin of the posterior scalp.

Lesser Occipital Nerve

A nerve originating from the anterior rami of spinal nerves $C2-C3$ that supplies the skin of the superior posterolateral neck and posterior ear region.

Conus Medullaris

The tapered lower extremity of the spinal cord, terminating around the level of the $L1-L2$ vertebrae in adults.

Cauda Equina

The collection of lumbar, sacral, and coccygeal spinal nerve roots descending within the lumbar cistern below the termination of the spinal cord.

Filum Terminale Internum

The delicate strand of pia mater extending from the apex of the conus medullaris down to the distal end of the dural sac at the $S2$ vertebral level.

Denticulate Ligament

Lateral saw-tooth extensions of pia mater that anchor the spinal cord to the surrounding dural sac.

Lumbar Cistern

The enlargement of the subarachnoid space inferior to the conus medullaris containing cerebrospinal fluid (CSF) and the cauda equina.

Lumbar Spinal Puncture

A clinical procedure performed in the lumbar cistern (typically between $L3-L4$ or $L4-L5$) to withdraw cerebrospinal fluid or introduce anesthesia without damaging the spinal cord.

Multifidus

A thick deep intrinsic muscle especially prominent in the lumbar region, running superomedially from sacral and lumbar processes across 2 to 4 segments to stabilize vertebrae.

Rotatores

The deepest transversospinalis muscles, best developed in the thoracic region, passing superomedially to attach 1 segment (brevis) or 2 segments (longus) above.

Atlas (C1)

The first cervical vertebra, which lacks a body and spinous process, consisting of paired lateral masses connected by anterior and posterior arches.

Axis (C2)

The second cervical vertebra, distinguished by the tooth-like dens (odontoid process) projecting superiorly from its body.