Back and Vertebral Column

Question 1

How many bones make up the vertebral column?

Answer 1

33 bones

• 7 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 4 coccygeal

Question 2

Which vertebrae of the vertebral column are fused?

Answer 2

Sacral and coccyx vertebrae

Question 3

What are the functions of the vertebral column?

Answer 3

• Weight bearing
• Protection of spinal cord, blood vessels and lymphatics
• Movement
• Site of muscle attachments (allows movement elsewhere)

Question 4

What features of the vertebral column provide shock absorption?

Answer 4

Curvatures

Intervertebral discs

Question 5

Describe kyphoses and lordoses

Answer 5

Kyphoses – outwards bending, present in foetus

Lordoses – inwards bend (develop later in development)

Question 6

Give some examples of lordoses

Answer 6

Cervical and lumbar lordoses

Question 7

Give some examples of kyphoses

Answer 7

Thoracic and sacral

Question 8

Name some abnormal curvatures of the back

Answer 8

Excessive thoracic kyphosis
Excessive lumbar lordosis
Scoliosis

Question 9

What type of bones are the vertebrae?

Answer 9

irregular

Question 10

What type of joint is formed by the intervertebral discs?

Answer 10

Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, and acts as a ligament to hold the vertebrae together.

Question 11

Describe the structure of an intervertebral disc

Answer 11

2 components: central core of nucleus pulposus with high water content surrounded by layers of fibrocartilage called the annulus fibrosus made up of both type I and type II collagen.

Question 12

What is spinal disc herniation and what usually causes it?

Answer 12

Spinal disc herniation, also known as a slipped disc, is a medical condition affecting the spine in which a tear in the outer, fibrous ring of an intervertebral disc allows the soft, central portion to bulge out beyond the damaged outer rings, and possibly compress the posterior spinal nerves to cause pain.
Disc herniation is usually due to age-related degeneration of the anulus fibrosus, although trauma, lifting injuries, or straining have been implicated

Question 13

Where are the tears in the annulus fibrosis that cause disc herniation usually found?

Answer 13

Tears are almost always postero-lateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal.

Question 14

What are the three meninges of the spinal cord?

Answer 14

Coverings of the spinal cord
– Dura mater (outside) - durable
– Arachnoid mater - spider legs
– Pia mater (inside)

Question 15

Briefly describe the movements of the back

Answer 15

Flexion/extension
Lateral flexion/extension
Rotation of head and neck and the upper trunk

Question 16

What type of joints are the facet joints?

Answer 16

Synovial plane (artiulation between vertebrae during movement)

Question 17

What types of joints are found between the vertebrae and the thoracic vertebrae?

Answer 17

Synovial plane (allows expansion of thorax during inhalation)

Question 18

What type of joint is found between the skull and the atlas?

Answer 18

Synovial ellipsoid (turning head round)

Question 19

What type of joint is found between the atlas and axis?

Answer 19

Synovial pivot (nodding)

Question 20

Describe the posterior longitudinal ligament and its function

Answer 20

Posterior longitudinal – prevents hyperflexion of the back, extends over posterior surfaces of the bodies of vertebrae

Question 21

Describe the anterior longitudinal ligament and its function

Answer 21

Anterior longitudinal – prevents hyperextension of the back, extends over the anterior surfaces of the bodies of the vertebrae

Question 22

Describe the ligamentum flavum and its function

Answer 22

Ligamentum flavum - connect the laminae (vertebral arches) of adjacent vertebrae, their elasticity serves to preserve the upright posture, and to assist the vertebral column in resuming it after flexion. The elastin prevents buckling of the ligament into the spinal canal during extension, which would cause canal compression. Main function is to keep column together.

Question 23

Describe the interspinous ligaments and its function

Answer 23

Interspinous ligaments - thin and membranous ligaments, that connect adjoining spinous processes of the vertebra in the spine, function is to limit flexion of the spine

Question 24

Describe the supraspinous ligament and its function

Answer 24

Supraspinous ligaments – a ligament found along the vertebral column which connects the tips of the spinous processes facing posteriorly on the body, which also helps to limit hyperflexion.

Question 25

What are extrinsic back muscles?

Answer 25

All back muscles that are connected to the limbs are called extrinsic muscles, which are superficial (close to the surface) and allow movements of the limbs e.g. shoulders and arms.

Question 26

What three muscles make up the erector spinae?

Answer 26

There are three intermediate intrinsic back muscles – the iliocostalis, longissimus and spinalis

Question 27

What do the intrinsic back muscles aid in?

Answer 27

These muscles all aid in extension, controlled flexion and lateral flexion of the back and spine

Question 28

Describe briefly some pathologies of the back that occur with age

Answer 28

• Dehydration of intervertebral discs → reduced shock absorption (also shrink)
• Osteoarthritis → pain & stiffness of joints
• Osteoporosis → compression fractures altering the curvature of the spine
• Weakness of back muscles → imbalanced loading of the spine resulting in back pain