Back Anatomy and Vertebral Column — Practice Flashcards

A comprehensive set of practice questions covering back anatomy, vertebral column structure, spinal cord and meninges, joints, muscles, pathologies, and clinical procedures.

What are the major bony elements forming the back’s skeletal framework?

Primarily the vertebrae, with proximal elements of the ribs, superior aspects of the pelvic bones, and posterior basal regions of the skull contributing to the framework.

How are back muscles categorized in terms of movement and function?

Into extrinsic muscles (move the upper limbs and ribs) and intrinsic muscles (maintain posture and move the vertebral column).

What is the difference in innervation between extrinsic and intrinsic back muscles?

Extrinsic muscles are generally innervated by anterior rami of spinal nerves, while intrinsic back muscles are innervated by the posterior rami.

What are the primary curvatures of the vertebral column and where are they located?

The primary curvatures are concave anteriorly and are in the thoracic and sacral regions.

What are the secondary curvatures and where do they develop?

The cervical and lumbar curvatures, which are concave posteriorly and develop to bring the center of gravity into a vertical line.

What are the two major types of joints between vertebrae?

Symphyses between vertebral bodies and synovial joints between the articular processes.

What components make up a typical vertebra?

A vertebral body, a vertebral arch (pedicles and laminae), spinous process, transverse processes, superior and inferior articular processes, and the vertebral foramen.

What are the intervertebral discs composed of and what are their parts?

An outer anulus fibrosus and a central nucleus pulposus.

What forms the walls of the vertebral canal?

The vertebral arches and ligaments along with adjacent vertebral bodies form the walls of the vertebral canal.

Describe the three meninges surrounding the spinal cord and their arrangement from inner to outer.

Pia mater (inner), arachnoid mater (middle), and dura mater (outer).

What is the subarachnoid space and what does it contain?

A space between the arachnoid and pia mater that contains cerebrospinal fluid (CSF). It extends to about the level of SII in adults.

What are the denticulate ligaments and what is their function?

Pia mater extensions that attach to the arachnoid and dura and help position the spinal cord in the center of the subarachnoid space.

What is cauda equina and why is it named so?

The bundle of lumbar and sacral nerve roots beyond the conus medullaris, resembling a horse’s tail.

What is the artery of Adamkiewicz and why is it important?

A large segmental medullary artery that reinforces the arterial supply to the lower spinal cord, usually arising on the left in the lower thoracic/upper lumbar region.

Which nerves innervate the intrinsic back muscles?

Posterior rami of spinal nerves.

Name the three columns of the erector spinae group.

Iliocostalis (lateral), longissimus (intermediate), and spinalis (medial).

What are the three main groups of transversospinales muscles?

Semispinalis, multifidus, and rotatores.

Which muscles comprise the superficial back muscle group?

Trapezius, latissimus dorsi, rhomboid major, rhomboid minor, and levator scapulae.

Which nerve primarily innervates the trapezius muscle?

Accessory nerve (cranial nerve XI).

Which nerve innervates the latissimus dorsi?

Thoracodorsal nerve (C6–C8).

Which nerve innervates the rhomboid muscles?

Dorsal scapular nerve (C4–C5).

Which nerves innervate the serratus posterior superior and serratus posterior inferior?

Anterior rami of intercostal nerves (T2–T5 for serratus posterior superior; T9–T12 for serratus posterior inferior).

What is the function of the rhomboid muscles?

Retract (adduct) the scapula and help rotate the lateral aspect of the scapula inferiorly; work with other muscles to stabilize the scapula.

What is the thoracolumbar fascia and what are its layers in the lumbar region?

A fascia covering the deep back muscles; in the lumbar region it has posterior, middle, and anterior layers with attachments to spinous processes, iliac crest, and transverse processes.

What are the three layers of the thoracolumbar fascia and their general attachments?

Posterior layer: spinous processes and supraspinous ligaments; Middle layer: tips of transverse processes and intertransverse ligaments; Anterior layer: covers the anterior surface of the quadratus lumborum and forms the lateral arcuate ligament for the diaphragm.

What are the functions of the ligamenta flava?

Elastic ligaments between adjacent laminae that resist separation in flexion and assist in returning to the erect position.

What is the supraspinous ligament and how does it relate to the ligamentum nuchae?

Supraspinous ligament runs along the tips of the spinous processes from C7 to the sacrum; in the neck it becomes the ligamentum nuchae, which supports the head.

What is the role of the interspinous ligaments?

They run between adjacent spinous processes and blend with the supraspinous ligament and ligamenta flava.

What is the difference between uncovertebral joints and uncovertebral joints’ location?

Uncovertebral joints are small synovial joints formed by the uncinate processes of typical cervical vertebrae with the body above.

What is spina bifida occulta and how might it present clinically?

Defect in the posterior arch of LV or S1 with failure to fuse midline; may have a tuft of hair and is often asymptomatic.

What is spina bifida with meninges or spinal cord protrusion called?

Meningocele or myelomeningocele, part of the more severe spina bifida.

What is vertebroplasty and what is it used for?

A procedure where bone cement is injected into a fractured vertebral body to increase strength and relieve pain, commonly used for osteoporotic wedge fractures.

What is scoliosis and what are its common types?

Abnormal lateral curvature of the spine with rotation; idiopathic scoliosis is most common; congenital scoliosis is associated with other anomalies; muscular dystrophy can also cause scoliosis.

What is kyphosis and what can cause a gibbus deformity?

Abnormal thoracic curvature causing a hunchback; can be dramatic in tuberculosis of the thoracic spine causing a gibbus.

What are the primary and secondary curvatures named in terms of common spinal terms?

Primary curvatures: thoracic and sacral (concave anteriorly). Secondary curvatures: cervical and lumbar (concave posteriorly, lordosis).

How many vertebrae are in each regional section (cervical, thoracic, lumbar, sacral, coccygeal)?

7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused into sacrum), 3–4 coccygeal (fused into coccyx).

What is the atlas (C1) distinctive feature and its relation to the axis (C2)?

Atlas lacks a vertebral body; C1 fuses its body with C2 to form the dens of C2; atlas articulates with the occipital condyles above and the axis below; allows nodding at the atlanto-occipital joint.

What joints stabilize the atlas and axis and what ligaments are involved in the dens’s stabilization?

Atlanto-axial joints stabilized by the transverse ligament of the atlas; alar ligaments connect the dens to the occipital condyles to limit rotation.

Where does the spinal cord end in adults, and where does the subarachnoid space end?

Spinal cord ends around the L1–L2 level; subarachnoid space ends at about the level of SII.

What is the cauda equina syndrome and why is it a surgical emergency?

Compression of multiple lumbar and sacral nerve roots resulting in severe pain, saddle anesthesia, bladder/bowel dysfunction; requires urgent decompression to prevent permanent damage.

What is the proper landmark for safely performing a lumbar puncture in adults?

Access the subarachnoid space in the lower lumbar region, typically between LIII–LIV or LIV–LV, where the spinal cord has ended but CSF-filled space remains.

What is the arrangement of the vertebral canal with respect to the dura and the subarachnoid space?

The dural sac surrounds the spinal cord and is separated from bone by the extradural space; dura continues with nerve sleeves to form epineurium around nerves; within the subarachnoid space CSF circulates around the cord.

What are the major spinal arteries that reinforce the anterior and posterior spinal arteries?

Segmental medullary arteries (including the artery of Adamkiewicz) reinforce the longitudinal arteries along the spinal cord.

What is the role of the dorsal and ventral roots in spinal nerves?

Posterior roots carry sensory information (with dorsal root ganglia); anterior roots carry motor fibers from the spinal cord. They join to form a spinal nerve which then splits into posterior and anterior rami.

What are the boundaries of the vertebral canal as seen in cross-section diagrams?

Anterior: vertebral bodies and intervertebral discs; Lateral: pedicles and intervertebral foramina; Posterior: laminae and ligamenta flava plus spinous processes.

What is the role of the denticulate ligaments in relation to the spinal cord and subarachnoid space?

They anchor the spinal cord laterally within the subarachnoid space, attaching to the arachnoid and dura mater to keep the cord centered.

Which vertebrae have ribs and what are the thoracic vertebrae characterized by?

The 12 thoracic vertebrae articulate with ribs; each thoracic vertebra has costal facets on the body and a transverse costal facet on the transverse process for rib articulation.

Which vertebral regions are characterized by large vertebral bodies and absence of costal facets?

Lumbar vertebrae; large bodies, long transverse processes, and no articulations with ribs.

What is spina bifida occulta’s clinical sign and how is it detected?

Tuft of hair over the spinous processes; asymptomatic; detected incidentally or by physical signs.

What is the function and location of the tectorial membrane?

Upper part of the posterior longitudinal ligament that extends to the base of the skull, reinforcing the craniovertebral junction.

How do vertebral bodies change in size along the column and why?

They increase in size inferiorly to accommodate increasing weight bearing as you move down the spine.

What is the clinical significance of the posterior spaces between laminae in the lumbar region?

There are gaps between adjacent laminae that widen with flexion, allowing relatively easy access to the vertebral canal for procedures.

Where is the posterior superior iliac spine located in relation to vertebral levels?

The posterior superior iliac spine aligns with the S2 vertebral level and marks the sacral dimples at the skin surface.

What landmarks help identify vertebral levels on the back for palpation?

External occipital protuberance, spine of scapula, medial border and inferior angle of scapula, iliac crest.

What is the common site to palpate to identify the LIV vertebral level?

LIV vertebral spinous process is level with the highest points of the iliac crests.

Which spinal nerves emerge above their corresponding vertebrae in the cervical region and below in others?

C2–C7 nerves emerge above their respective vertebrae; C8 emerges below C7 (between C7 and T1); all other spinal nerves emerge below their corresponding vertebrae.

What are the main components of the vertebral arch that articulate with adjacent vertebrae?

Pedicles (attach to the body) and laminae (form the roof of the arch) and the superior/inferior articular processes that articulate with adjacent vertebrae.

What is the typical pattern of curvatures when viewed from the side?

Primary curvatures in thoracic and sacral regions (concave anteriorly); secondary curvatures in cervical and lumbar regions (concave posteriorly).