Anatomy of the Spine and Vertebrae

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Questions and Answers

What characterizes a herniated disc?

It only causes lower limb weakness.

The nucleus pulposus protrudes through a tear in the annulus fibrosis. (correct)

It does not affect the spinal cord.

The outer annulus fibrosis remains intact.

Which condition is associated with perianal paraesthesia?

Cauda equina syndrome (correct)

Scoliosis

Lordosis

Kyphosis

What is the result of abnormal curvature in lordosis?

An exaggerated curve in the lower back or neck area. (correct)

Lumbar disc herniation.

A sideways curve resembling an S-shape.

A rounding in the upper back resembling a hump.

Which of the following symptoms is NOT typically associated with cauda equina syndrome?

Hump in the upper back Signup and view all the answers

What happens during the process of bulging disc formation?

The outer annulus fibrosis remains intact but pushes into the spinal canal. Signup and view all the answers

What does the term 'alignment' refer to in spine imaging?

The assessment of multiple lines in medical images. Signup and view all the answers

Which line runs along the anterior edge of the spinous processes in a lateral view of the spine?

Spinolaminar line Signup and view all the answers

What does a loss of vertebral height typically indicate?

Potential fracture Signup and view all the answers

Which imaging modality is preferred for concerns about intervertebral disc integrity?

MRI Signup and view all the answers

What appearance is associated with late-stage ankylosing spondylitis?

Bamboo spine Signup and view all the answers

What is spondylosis primarily characterized by?

Degeneration of the intervertebral disc Signup and view all the answers

In the three-column model of spinal fractures, instability occurs when injuries affect how many contiguous columns?

Two Signup and view all the answers

What is a common radiographic appearance of spondylolysis?

Scotty dog Signup and view all the answers

Which spinal condition involves the vertebrae being displaced forward upon another?

Spondylolisthesis Signup and view all the answers

What is the first line of assessment when checking for bone integrity in spine imaging?

Inspecting the cortex of every bone Signup and view all the answers

What structure is found between the C1 and C2 vertebrae?

Dens Signup and view all the answers

Which type of joint exists between successive vertebrae?

Symphysis Signup and view all the answers

Which ligament connects the spinous processes of the cervical vertebrae to the skull?

Ligamentum nuchae Signup and view all the answers

What describes the primary curvatures of the spine?

Kyphotic curves that are convex posteriorly Signup and view all the answers

Which of the following is NOT a classification for spinal muscles?

Bilateral Signup and view all the answers

Which ligament runs along the anterior surface of the vertebral canal?

Anterior longitudinal ligament Signup and view all the answers

What is the primary function of intervertebral discs?

Shock absorption Signup and view all the answers

Which spinal nerves are responsible for delivering motor and autonomic fibers?

Anterior roots Signup and view all the answers

What is the unique anatomical feature of C1 (atlas)?

It lacks a vertebral body Signup and view all the answers

What type of blood supply serves the spinal cord?

Anterior spinal artery and its contributions Signup and view all the answers

Which muscles belong to the deep group of extrinsic spinal muscles?

Spinotransversales muscles Signup and view all the answers

Which imaging modalities are commonly used for the neck and spine?

X-rays, CT scans, and MRIs Signup and view all the answers

What structure is formed by the fusion of anterior and posterior roots?

Spinal nerve Signup and view all the answers

Study Notes

The Spine - Bony Structures

The spine consists of 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), and 4 coccygeal (fused).
Each vertebra contains a body, pedicles, vertebral foramen, vertebral arch, transverse process, spinous process, laminae, and superior and inferior articular processes.
The vertebral foramina form the vertebral canal, which houses the spinal cord.
Intervertebral foramina, formed by vertebral notches of successive vertebrae, allow the passage of spinal nerves and blood vessels.

C1 and C2 Vertebrae

C1 (atlas) directly articulates with the skull and lacks a vertebral body, containing two lateral masses connected by anterior and posterior arches.
C2 (axis) has a prominent dens that acts as a pivot point for head movement.
The joint between C1 and C2 is stabilized by the transverse ligament of the atlas, alar ligaments, and apical ligament of the dens.

Spine Joints

Symphyses joints are found between the superior and inferior surfaces of successive vertebrae, containing intervertebral discs that act as shock absorbers.
Synovial joints, known as zygapophysial joints, are located between articular processes of vertebrae.

Spine Ligaments

Anterior and posterior longitudinal ligaments run along the anterior and posterior surfaces of vertebral bodies, respectively.
Ligamenta flava connect the posterior surface of the lamina of the vertebra below to the anterior surface of the lamina of the vertebra above.
Supraspinous ligament connects the spinous processes of CVII to the sacrum, while the ligamentum nuchae connects the cervical vertebrae to the skull.
Interspinous ligaments connect adjacent vertebral spinous processes.

Curvatures of the Spine

Primary curvatures (kyphosis): thoracic and sacral/coccygeal curvatures, present during fetal development.
Secondary curvatures (lordosis): cervical and lumbar curvatures, form after birth.

Spinal Muscles

Extrinsic muscles (superficial and intermediate): move the upper limbs and thoracic wall, innervated by anterior rami of spinal nerves.
Intrinsic muscles (deep): support and move the vertebral column and head, innervated by posterior rami of spinal nerves.

Superficial Spinal Muscles

Latissimus dorsi, trapezius, levator scapulae, rhomboid major, and rhomboid minor.

Intermediate Spinal Muscles

Serratus posterior superior and serratus posterior inferior.

Deep Spinal Muscles

Spinotransversales: splenius capitis and splenius cervicis.
Erector spinae: iliocostalis, longissimus, and spinalis.
Transversospinales: semispinalis, multifidus, and rotatores.
Segmental muscles and suboccipital muscles.

Posterior Neck Muscles

Superficial group: latissimus dorsi, trapezius, levator scapulae, rhomboid major, and rhomboid minor.
Intermediate group: serratus posterior superior and serratus posterior inferior.
Deep group: splenius capitis, splenius cervicis, iliocostalis, longissimus, spinalis, semispinalis, multifidus, rotatores, segmental muscles, and suboccipital muscles.

The Spinal Cord

Lies within the vertebral canal, surrounded by meninges (pia, arachnoid, and dura).
Has a cervical enlargement around C5-T1 and tapers to the conus medullaris at L1-L2, anchored to the coccyx by the filum terminale.
Cauda equina: nerve roots from L1-S5 descending within the vertebral canal.
External surface marked by anterior median fissure, posterior median sulcus, and posterolateral sulci.
Internally contains grey matter surrounding a central canal and white matter.

Spinal Cord Vasculature

Supplied by the anterior spinal artery and posterior spinal arteries.

Spinal Nerves

31 pairs of spinal nerves emerge from the vertebral canal between pedicles: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal.
Each nerve has an anterior root (efferent, motor, and autonomic fibers) and a posterior root (afferent, sensory fibers).
Anterior and posterior roots fuse to form a mixed nerve that branches into anterior and posterior rami.

ABC of Spine Images

Alignment: anterior longitudinal line, posterior longitudinal line, spinolaminar line, lateral lines, and spinous process line.
Bones: assess cortex and bone integrity for continuity and vertebral height; assess endplates, pedicles, laminae, and spinous processes.
Cartilage: intervertebral disc size should increase inferiorly; note L5/S1 space is often narrower than L4/L5.

Spinal Pathologies

Ankylosing Spondylitis: inflammatory arthritis of the spine, leading to vertebral and sacroiliac joint fusion.
Spondylosis: degenerative disc disease causing narrowing, endplate sclerosis, and osteophyte formation.
Fractures:
- Three-column model: divides the spine into anterior, middle, and posterior columns.
- Spondylolysis: fracture in the pars interarticularis.
Spondylolisthesis: displacement of one vertebra forward upon another.
Bulging and Herniated Discs:
- Bulging disc: protrusion of annulus fibrosis without a tear.
- Herniated disc: nucleus pulposus protrudes through an annular tear.
Cauda Equina Syndrome: compression of lumbar and sacral nerve roots, often due to a herniated disc, causing symptoms such as saddle anesthesia, lower limb weakness, reduced reflexes, radiculopathy, and bowel/bladder dysfunction.
Abnormal Curvatures:
- Kyphosis: rounding of the upper back.
- Lordosis: increased curvature in the lower back or neck.
- Scoliosis: lateral curvature of the spine.

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Description

This quiz covers the anatomy of the spine, including the structure and function of vertebrae, particularly the unique features of C1 and C2 vertebrae. Understand the role of intervertebral foramina and the types of joints present in the spine. Test your knowledge of these essential elements of human anatomy.