Vertebral Column, Spinal Cord, and Spinal Nerves

Question 1

What condition does this person have?

Answer 1

Kyphosis

Question 2

What condition does this person have?

Answer 2

Lordosis

Question 3

What condition does this person have?

Answer 3

Scoliosis

Question 4

What structure is pictured below, and what are its parts?

Answer 4

Superior view of a cervical vertebra (3-7)

Question 5

What structure is pictured below, and what are its parts?

Answer 5

Right lateral view of a cervical vertebra (3-7)

Question 6

What structure is pictured below, and what are its parts?

Answer 6

Superior view of a thoracic vertrebra

Question 7

What structure is pictured below, and what are its parts?

Answer 7

Right lateral view of a thoracic vertebra

Question 8

What structure is pictured below, and what are its parts?

Answer 8

Superior view of a lumbar vertebra

Question 9

What structure is pictured below, and what are its parts?

Answer 9

Right lateral view of a lumbar vertebra

Question 10

What are the curvatures of the spine, and when do they develop?

Answer 10

Primary curvatures: thoracic and sacral, concave anteriorly. Develop during the embryonic period

Secondary curvatures: cervical and lumbar, concave posteriorly. Develop when an infant holds his/her head up and begins to walk, respectively

Question 11

What ligament connects the lamina of two vertebrae?

Answer 11

Ligamentum flavum

Question 12

In this section, what structure is missing its labels, and what are the labels?

Answer 12

Show below is an intervertebral disc.

The two parts that were missing labels are the nucleus pulposus and the anulus fibrosus.

Question 13

What structures below are missing their labels?

Answer 13

The spinal ligaments

Question 14

Against what injuries do the anterior and posterior longitudinal ligaments protect, respectively?

Answer 14

Anterior longitudinal ligament: hyperextension (whiplash)

Posterial longitudinal ligament: hyperflexion

Question 15

What are the spinal meninges?

Answer 15

Three layers that protect the spine. From outermost to innermost: dura mater, arachnoid mater, and pia mater.

Question 16

Where does the spinal cord end in adults and children?

Answer 16

Adults: L1/L2

Children: L3/L4

Question 17

What is the extradural/epidural space?

Answer 17

The potential space between the bony vertebral canal and the dura mater. Contains the internal vertebral venous plexus. The site for some medical interventions, such as “epidurals” for women in labor.

Question 18

What is the subarachnoid space?

Answer 18

The space between the arachnoid and pia mater. Contains CSF. The preferred site for a lumbar puncture.

Question 19

What and where is the lumbar cistern?

Answer 19

The preferred site of CSF withdrawal, since the spinal cord proper ends and the nerve roots of the cauda equina are mobile. Located in the subarachnoid space between L2 and S2.

Question 20

What landmark can be used to help determine the location of the lumbar cistern?

Answer 20

The peak of the iliac crests is about level with L4.

Question 21

What structures must be pierced in a lumbar puncture, and in what order?

Answer 21

Think: “Some Super Supra Long L E Ds Are Sexy.”

• Skin
• Superficial fascia
• Supraspinous ligament
• Ligament (Interspinous)
• Ligamentum flavum
• Epidural space containing the internal vertebral venous plexus
• Dura mater
• Arachnoid
• Subarachnoid space containing CSF

Question 22

What structure is pictured below, and what are its parts?

Answer 22

Transverse section of the spinal cord

Question 23

What is the most common fracture mechanism in spinal cord injuries?

Answer 23

Hyperflexion, which can rupture posterior ligaments. Can be accompanied by fracture of the spinous process through compression.

Question 24

What is a common, negative outcome of diving injuries?

Answer 24

Vertical compression injuries. Usually a burst fracture at cervical level.

Question 25

What spinal cord injury can occur as a result of hyperextension?

Answer 25

Extension teardrop fracture. Manifests with a displaced anteroinferior bony fragment. Occurs when the anterior longitudinal ligament pulls a bony fragment away from the inferior aspect of the vertebra because of the sudden hyperextension. The fragment is a true avulsion, in contrast to the flexion teardrop fracture in which the fragment is produced by compression.

Question 26

What kind of nerve fibers do spinal nerves contain?

Answer 26

Spinal nerves contain MIXED fibers: both afferent (motor) fibers from ventral roots and efferent (sensory) fibers from dorsal roots. Spinal nerves quickly diverge into dorsal and ventral rami, which also contain mixed fibers.

Question 27

What is a **dermatome**?

Answer 27

The area of skin supplied by the sensory branches of a single spinal nerve. Most dermatomes overlap, so destruction of a single spinal nerve will not cause complete numbness.

Question 28

What is a **myotome**?

Answer 28

The group of muscles (muscular fibers) innervated by the same spinal segment. One muscle could be innervated by fibers originating in more than one spinal nerve.

Question 29

Label the structures below.

Answer 29

1) Trapezius 2) Latissimus dorsi 5) Levator scapulae 6) Rhomboid minor 7) Rhomboid major