HNS Anatomy 2 - Spinal Cord

Question 1

List the functions of the vertebral column

Answer 1

Support and protection

• Body weight
• Transmits forces
• Supports the head
• Supports the upper limbs (and aids movement)
• Spinal cord (protective role)

Movement

• Upper limbs and ribs (extrinsic muscles, which go outside of the vertebral column)
• Postural control and movement (intrinsic muscles which remain inside the vertebral column)

Question 2

List the curvatures of the vertebral column present in a normal adult

Answer 2

• Cervical (secondary)
• Thoracic (primary)
• Lumbar (secondary)
• Sacral (primary)

Question 3

What is the function of the vertebral body?

Answer 3

It is the major weight bearing part

Question 4

List the functions of the vertebral arch

Answer 4

• Forms the roof of the vertebral canal
• Has projections for attachment of muscles and ligaments
• Has sites of articulation for adjacent vertebrae

Question 5

What is the function of the pedicles?

Answer 5

Anchor the vertebral arch to the vertebral body

Question 6

List the typical features of cervical vertebrae

Answer 6

• Vertebral body (bean shape) is short in height and square shaped when viewed from above, with a concave superior surface and convex inferior surface
• Each transverse process is trough shaped perforated by a round foramen transversarium
• Short and bifid spinous process with a triangular vertebral foramen

Question 7

List the typical features of the axis and atlas

Answer 7

• No intervertebral disc between the two - as the vertebral body of C1 forms the dens of C2
• C1 lacks a vertebral body
• Atlas is ring shaped with two lateral masses interconnected by an anterior and posterior arch

Question 8

List the typical features of the thoracic vertebrae

Answer 8

• Characterised by their articulation with ribs, typically 2 partial facets (superior and inferior) on each side of the vertebral body.
• Superior costal facet is much larger than inferior
• Transverse processes have facets for articulation with the tubercle of each rib
• Vertebral body is heart shaped
• Vertebral foramen is circular

Question 9

List the characteristics of lumbar vertebrae

Answer 9

• Large size
• Lack facets for rib articulation
• Long and thin transverse processes (except L5 which are massive and cone shaped)
• Vertebral body is cylindrical (kidney shaped)
• Vertebral foramen is triangular, larger than thoracic

Question 10

List the characteristics of the sacrum

Answer 10

• Triangluar shape, apex inferiorly projecting
• Curved with a concave anterior surface
• Articulates with L5 and the coccyx
• Two large L shaped facets for articulation with the pelvic bones
• 4 pairs of sacral foramina on the anterior surface and posterior surface

Question 11

List the characteristics of the coccyx

Answer 11

• Small triangular bone, represents 3-4 fused coccygeal vertebrae
• Small size and absence of vertebral arches and therefore vertebral canal

Question 12

Describe the structure of intervertebral discs

Answer 12

• Anulus fibrosis outside

- Nucleus pulposis inside

Question 13

List the movements of the spine and the muscles involved

Answer 13

• Extension (lean back - erector spinae)
• Flexion (rectus abdominis/psoas major)
• Lateral flexion (leaning side to side - oblique muscles, rhomboid, serratus anterior)
• Rotation - oblique muscles, sternocleidomastoid, erector spinae

Question 14

List the common spinal pathologies

Answer 14

• Low back pain
• Prolapsed intervertebral disc (sciatica)
• Spondolysis (degeneration)
• Spondylolysis (stress fracture of pars interarticularis)
• Spondylolisthesis (forward displacement of vertebra)
• Spondylitis (inflammation of vertebrae)

Question 15

List the abnormal curvatures of the spine

Answer 15

• Excessive kyposis, often seen in older people - can be normal (cervical curve)
• Excessive lordosis - can be normal or exaggerated (lumbar curve)
• Scoliosis, more common in females during puberty (lateral curve)

Question 16

Describe the development of the curvatures

Answer 16

• Primary curvatures have concave side facing anteriorly (these are the same as in a foetus)
• Secondary curvatures have a convex side facing posteriorly (develop through age)

Question 17

When is the lumbar curvature enhanced?

Answer 17

• In obesity
• In pregnancy
• To move the centre of gravity backwards

Question 18

Why are the intervertebral discs important?

Answer 18

• They help to bear weight

- They allow rotation of the spine

Question 19

Where are the alar ligaments?

Answer 19

From the skull to the odontoid peg

Question 20

Why is the atlantooccipital joint called the yes joint?

Answer 20

Because this joint allows us to nod our heads (flexion and extension)

Question 21

Why is the atlantoaxial joint called the no joint?

Answer 21

This joint allows us to shake our head (rotation)

Question 22

What is an important risk of the intervertebral discs reducing in height?

Answer 22

• The intervertebral foramen becoming smaller

- This crushes the nerves emerging from the foramen, and can result in pain

Question 23

What is the cauda equina?

Answer 23

• The bundle of nerves making their way down from the spinal cord, which ends at L2, to the lower vertebrae.
• Here injections are placed for anaesthetic/epidural

Question 24

What is a prolapsed intervertebral disc?

Answer 24

• The nucleus pulposis herniates into the vertebral canal, which results in nerve impingement, pain and sciatica (pain radiating down the leg)
• More likely further down the spine as there is more weight being transmitted

Question 25

Describe the range of motion of the cervical spine

Answer 25

- Rotation (L/R 80 degrees) - Extension and flexion (45 degrees) - Right and left lateral flexion (45 degrees)

Question 26

Describe the range of motion of the thoracolumbar spine

Answer 26

- Extension (30 degrees) - Flexion (90 degrees) - Lateral flexion (30 degrees) - Rotation (L/R 30 degrees)

Question 27

Where do the different layers of the meninges end in the spinal cord?

Answer 27

- Pia mater ends with the spinal cord (L2) at the filum terminale, which extends down from the base of the spinal cord alongside the cauda equina - Arachnoid and dura mater extend down to the level of S2 vertebra, so there is a large epidural space

Question 28

When are needles inserted to the epidural space via the sacral hiatus?

Answer 28

- In patients with severe sciatica, anaesthetics and analgesics are administered. - This can reduce inflammation and reduce need for disc surgery.

Question 29

Compare the location of epidural and spinal anaesthetics

Answer 29

- Epidural in the epidural space (used for the duration of labour, over many hours) - Spinal in the subarachnoid space (used for a procedure of known length, such as C-section/ hip replacement, if someone is not fit for general anaesthetic)

Question 30

What is the conus medullaris?

Answer 30

The tapered lower end of the spinal cord

Question 31

Where is the nuchal ligament?

Answer 31

At the back of the neck, continuous with the supraspinous ligament

Question 32

Which ligament is most likely to be damaged in whiplash?

Answer 32

Anterior longitudinal ligament

Question 33

List the functions of the trapezius muscle

Answer 33

- Elevates and depresses the scapula - Rotates the arm - Retracts the scapula

Question 34

List the functions of the rhomboid major and minor muscles

Answer 34

- Depress the scapula | - Retracts the scapula

Question 35

Where does prostate cancer commonly metastasise to?

Answer 35

The vertebral body, which can result in compressed spinal cord

Question 36

List the muscles making up the erector spinae

Answer 36

- Illiocostalis - Longissimus - Spinalis (I like standing) - lateral to medial

Question 37

Compare the dura in the brain and in the spinal cord

Answer 37

- In the brain, there are two layers - meningeal and periosteal - In the spinal cord there is only the meningeal layer

Question 38

Describe what is looked at initially in a spinal examination

Answer 38

- Look at curvatures - Wide stance suggests stenosis - Look for asymmetry (shoulder blades and pelvis)

Question 39

Describe the assessment of the cervical spine

Answer 39

- Split into two (upper and lower) - Look for musclar atrophy (or increased tone) or asymmetry in the shoulders and upper limbs - Look at movements - flexion (head moved forwards), extension (head moved backwards), lateral flexion, and rotation of the head - Protraction and retraction of the head can also be looked at - C7 is the first vertebra you can see and feel - C1 and 2 rotation is used and the transverse processes are held - Look for associated movement in the thoracic spine

Question 40

Describe the process of a thoracic spine examination

Answer 40

- Patient sits down, places their hands on the opposite shoulder and moves forwards (flexion) - Extension - patients puts their hands on neck and leans backwards - Patient puts hands on the same shoulder and rotates either side - To look at pain, do a percussion test (palpate the spinous process and tap, see if the patient feels pain to detect a vertebral compression fracture)

Question 41

Describe the assessment of the lumbar spine

Answer 41

- Look for lordosis - Flexion (run hands down thighs as far as you can), Extension (run hands down back of legs) - Look at where movement takes place - Latriflex their hand down the side of each leg - Palpation is used to identify pain (use iliac crest for L4 level) use a thumb and gentle compression

Question 42

Describe the assessment of the sacro-iliac joint

Answer 42

- Compression test (hold and compress the iliac crest) - To compress the sacro-iliac joint push the iliac crests outwards - Gaenslen test - drop one leg off the table and then push the other knee towards the chest - Thigh thrust test - press down on the knee through the thigh - Roll onto their tummy and push the sacrum down - 3/5 tests increases likelihood of pain arising from sacro-iliac joint by 50%

Question 43

Describe the process of assessing spinal posture

Answer 43

Ask them to lift their chest and bring into a neutral posture

Question 44

Describe the neural assessment of the spine in the upper limbs

Answer 44

- Reflexes (brachial, pectoralradialis, triceps, c7 (thumb flexion is hoffmans reflex) - Look at myotomes - pressure into your hand, shrug shouler, adduct the arm and maintain pressure, flex arm, bring their thumb up, extend the wrist, grip the hand - Sensation - light touch along the arm and pinprick

Question 45

When is neural assessment of the spine undertaken?

Answer 45

- Spinal fracture - Cervical myelopathy - Assess the neural integrity - reflexes, myotomes and dermotomes

Question 46

Describe the neural assessment of the spinal cord in the legs

Answer 46

- Reflexes - hyporeflexia/hyper (knee, ankle) - Push foot upwards, flex toes against opposing pressure - Up and down 3 times when standing on one foot - Sensation (sweep a hand along the dermatomes) and then pinprick - Look for fanning of the toes and big toe extension as well as beating on the foot - Straight leg raise and dorsiflex the foot. - Crossed over straight leg raise (when disc prolapse occurs) - Thrust test (flex head and straighten leg)