20 Most Important MCQs: Vertebral Column (Bones, Joints, Muscles & Blood Supply)

SECTION A: BONES OF THE VERTEBRAL COLUMN

• A) 28
• B) 30
• C) 33
• D) 26

The adult vertebral column has 26 bones: 7 cervical, 12 thoracic, 5 lumbar, 1 sacrum (5 fused), and 1 coccyx (3-4 fused). In childhood there are 33 separate vertebrae before fusion occurs.

• A) C2 (Axis)
• B) C1 (Atlas)
• C) C3
• D) C7 (Vertebra prominens)

The atlas (C1) is a ring-shaped vertebra with NO vertebral body - this was incorporated into the body of C2 (axis) as the odontoid process (dens) during development. It has large lateral masses with articular facets superiorly for the occipital condyles.

• A) Intervertebral disc of C1-C2
• B) Vertebral body of C1 (atlas)
• C) Anterior arch of C1
• D) Spinous process of C1

The dens of C2 is the incorporated body of C1. It projects superiorly and articulates with the anterior arch of the atlas, forming the atlantoaxial joint which allows rotation of the head (about 50% of cervical rotation).

• A) Spinous process
• B) Transverse foramina (foramen transversarium)
• C) Facet joints
• D) Intervertebral foramen

Cervical vertebrae C1-C6 have transverse foramina that transmit the vertebral artery, vertebral vein, and sympathetic nerves. The vertebral artery enters at C6 (occasionally C7). C7 contains only accessory veins or no significant vessels.

• A) C6 - because it has the longest transverse process
• B) C7 - because it has the longest, most prominent non-bifid spinous process
• C) T1 - because it is the most prominent thoracic vertebra
• D) L5 - because it is the largest lumbar vertebra

C7 is called vertebra prominens because its spinous process is the longest and most prominent in the cervical region and is not bifid (unlike C2-C6). It is easily palpable at the back of the neck and used as a bony landmark in clinical practice.

• A) Cervical and lumbar
• B) Thoracic and sacral
• C) Cervical and thoracic
• D) Lumbar and sacral

Primary curves (thoracic and sacral kyphoses) are concave anteriorly and are present at birth, retaining the fetal "C-shape." Secondary curves (cervical and lumbar lordoses) are concave posteriorly and develop after birth - cervical when the infant lifts its head, lumbar when the child stands and walks.

SECTION B: JOINTS OF THE VERTEBRAL COLUMN

• A) Hyaline cartilage alone
• B) Fibrocartilage alone
• C) An intervertebral disc between two layers of hyaline cartilage
• D) A synovial joint with a joint capsule

Each intervertebral disc lies between a layer of hyaline cartilage on each vertebral body. The disc itself consists of an outer annulus fibrosus (collagen + fibrocartilage) surrounding a central nucleus pulposus. This is a secondary cartilaginous joint (symphysis). (Gray's Anatomy for Students)

• A) Annulus fibrosus
• B) Nucleus pulposus
• C) Hyaline cartilage endplate
• D) Posterior longitudinal ligament

The nucleus pulposus is a gelatinous, highly hydrated central core rich in proteoglycans. It absorbs compression forces between vertebrae. Embryologically, it is derived from the notochord. The annulus fibrosus limits rotation. (Gray's Anatomy for Students)

• A) Anterior spinal artery
• B) The spinal cord directly
• C) The nerve root in the intervertebral foramen
• D) The posterior longitudinal ligament

Posterolateral herniation is the most common direction because the posterior longitudinal ligament reinforces the central posterior disc. The herniated nucleus pulposus material tracks into the intervertebral foramen and compresses the descending nerve root, causing radiculopathy. (Gray's Anatomy for Students)

• A) Primary cartilaginous (synchondrosis)
• B) Secondary cartilaginous (symphysis)
• C) Synovial plane joints
• D) Fibrous (syndesmosis)

The zygapophysial joints (between superior and inferior articular processes of adjacent vertebrae) are synovial joints enclosed by a thin articular capsule. Their orientation varies by region - this determines the type of movement allowed. (Gray's Anatomy for Students)

• A) Cervical
• B) Thoracic
• C) Lumbar
• D) Sacral

• Cervical: joints slope inferiorly (anterior to posterior) - facilitate flexion/extension
• Thoracic: joints oriented vertically - facilitate rotation, limit flexion/extension
• Lumbar: curved, interlocking surfaces - limit rotation, allow flexion/extension (Gray's Anatomy for Students)

• A) Anterior longitudinal ligament
• B) Posterior longitudinal ligament
• C) Ligamentum flavum
• D) Supraspinous ligament

The ligamentum flavum (Latin: "yellow ligament") contains a high proportion of elastic fibres, giving it its yellow colour. It connects adjacent laminae, helps maintain upright posture, and is clinically important as a landmark for epidural/spinal anaesthesia. Hypertrophy of this ligament can cause spinal canal stenosis.

• A) Flexion and extension ("yes" movement)
• B) Rotation ("no" movement)
• C) Lateral flexion
• D) Circumduction

The atlantoaxial joint (C1-C2) is a pivot joint that allows approximately 50% of total cervical rotation (shaking the head "no"). The atlanto-occipital joint (C0-C1) allows flexion/extension (nodding "yes"). The transverse ligament of the atlas holds the dens in place against the anterior arch of the atlas.

SECTION C: MUSCLES OF THE VERTEBRAL COLUMN

• A) Iliocostalis, Longissimus, Spinalis
• B) Spinalis, Longissimus, Iliocostalis
• C) Multifidus, Rotatores, Semispinalis
• D) Semispinalis, Longissimus, Iliocostalis

The erector spinae is the large superficial muscle mass of the deep back. Mnemonic: "I Love Spain" - Iliocostalis (lateral), Longissimus (middle), Spinalis (medial). Together they extend and laterally flex the vertebral column. (Gray's Anatomy for Students)

• A) Protracts the scapula
• B) Provides fine rotatory control and postural stabilization of the vertebral column
• C) Flexes the vertebral column
• D) Elevates the ribs during respiration

The transversospinales muscles run from transverse processes to spinous processes of vertebrae above (hence the name). Multifidus is especially important for lumbar stability. The rotatores rotate vertebrae contralaterally. All are innervated by dorsal rami of spinal nerves.

• A) Anterior (ventral) rami of spinal nerves
• B) Posterior (dorsal) rami of spinal nerves
• C) Autonomic plexuses
• D) Intercostal nerves only

The deep (intrinsic) muscles of the back are supplied exclusively by the posterior (dorsal) rami of spinal nerves. The superficial back muscles (trapezius, latissimus dorsi, rhomboids, levator scapulae) are supplied by anterior rami and cranial nerves - they are really upper limb muscles that have migrated to the back.

SECTION D: BLOOD SUPPLY

• A) One anterior and one posterior (total 2)
• B) One anterior and two posterior (total 3)
• C) Two anterior and two posterior (total 4)
• D) One single central artery

The spinal cord is supplied by:

• 1 anterior spinal artery (midline, anterior median fissure) - supplies ~75% of cord (anterior 2/3)
• 2 posterior spinal arteries (posterolateral sulci) - supply ~25% of cord (posterior 1/3 including dorsal columns) (Gray's Anatomy for Students, Miller's Anesthesia)

• A) Internal carotid arteries
• B) Vertebral arteries
• C) Subclavian arteries
• D) Basilar artery

The anterior spinal artery originates within the cranial cavity as the union of two contributing branches from the left and right vertebral arteries. It then descends along the anterior median fissure of the entire spinal cord. (Gray's Anatomy for Students)

• A) It is the main supply to the cervical cord
• B) It is the largest segmental artery and the main supply to the lower 2/3 of the spinal cord
• C) It supplies the posterior spinal arteries exclusively
• D) It arises from the right side in 80% of people

The artery of Adamkiewicz typically enters on the left side (in ~80% of people) between T8 and L1 (most commonly T9-T12). It is the dominant segmental medullary artery supplying the lower thoracic and lumbar spinal cord via the anterior spinal artery. Damage during aortic surgery can cause paraplegia. (Bailey & Love's Surgery, Gray's Anatomy for Students)

• A) Posterior spinal artery
• B) Artery of Adamkiewicz / Anterior spinal artery
• C) Vertebral artery
• D) Posterior inferior cerebellar artery (PICA)

This is classic anterior spinal artery syndrome: the anterior spinal artery supplies the anterior 2/3 of the cord (including corticospinal tracts and spinothalamic tracts). Occlusion causes:

• Motor loss (corticospinal tract) below the level
• Loss of pain and temperature (spinothalamic tract) below the level
• Preserved proprioception and vibration (posterior columns, supplied by posterior spinal arteries) The artery of Adamkiewicz is the main supply to the lower cord via the anterior spinal artery.

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