Lecture 2.1

Question 1

What are the boundaries of the back?

Answer 1

Back extends from the first thoracic vertebra until the coccyx. and between the scapulae of both sides and the iliac crest.

Question 2

Where is the nerve supply better the skin of the back or the skin of the abdomen?

Answer 2

Nerve supply is much less than the stomach. 2 point discrimination on the back is much less than the stomach.

Question 3

Where on the rib is damage typically seen?

Answer 3

At the point where the rib bends anteriorly.

Question 4

How much of the skin of the body does the back contain? Why is this important?

Answer 4

18%. Rule of nines. This fact is important when talking about burns and how much fluid is lost and in need of replacement.

Question 5

What is the secondary curvature of the back called?

Answer 5

Secondary curvature of the back is called lordosis.

Question 6

What is cranial and caudal shift of the spine?

Answer 6

Cranial shift or caudal shift is seen as a shift of features of the spine either caudally or cranially. An example of this is the cervical rib or a long transverse process in a lumbar vertebra.

Question 7

Why do vertebral bodies contain lots of holes?

Answer 7

For veins. (Vertebral bodies are highly vascular)

Question 8

What can be said about the size of intervertebral disks?

Answer 8

Disks are typically narrow in the cervical and thoracic spine but in the lumbar spine they become larger. Due to increased weightbearing demands.

Question 9

Where does the spinal cord pass through?

Answer 9

The vertebral column

Question 10

Where does the spinal cord terminate?

Answer 10

L1/2.

Question 11

Where do spinal nerves emerge from?

Answer 11

Spinal nerves emerge from intervertebral foramina.

Question 12

What are superficial back muscles?

Answer 12

Superficial back muscles are the extrinsic muscles of the back that contain one attachment to the back and the other attachment typically to the upper limb..

Question 13

What are deep back muscles?

Answer 13

Deep back muscles (intrinsic muscles) origin and insertion are within the back.

Question 14

What are vertebral pedicles and laminae?

Answer 14

Pedicle connects arch to the body. Lamina connect pedicle to spinous process on each side.

Question 15

How does the rib connect to thoracic vertebrae?

Answer 15

Articular facets for joints of the rib are present on the vertebral body and the transverse processes.

Question 16

In what direction do sacral vertebrae fuse?

Answer 16

Sacral vertebrae typically fuse from the inferior vertebrae to the superior.

Question 17

How are articular processes oriented in the vertebral column?

Answer 17

Lumbar vertebrae are typically in the sagittal plane. Lumbosacral joint is in a coronal plane.

Question 18

What do the sacral foramina contain?

Answer 18

Sacral foramina contain sacral nerve roots and sacral veins.

Question 19

What is the difference between veins of the body cavities and the veins within limbs?

Answer 19

Veins in the body cavities do not contain valves. eg. sacral veins.

Question 20

What veins drain vertebral bodies? Where does this blood go before going to the anterior side of the body?

Answer 20

Vertebral bodies are drained by basivertebral veins. Basivertebral veins drain into internal vertebral venous plexuses which drain into external vertebral venous plexuses these drain into sacral veins.

Question 21

What is another function of intervertebral venous plexuses?

Answer 21

Internal venous plexuses protect the spinal cord by cushioning it within the vertebral canal (surround the dura)

Question 22

What do veins follow to the front of the body?

Answer 22

Veins accompany arteries to the front of the body.

Question 23

Where do lymphatics go from the back of the body?

Answer 23

Lymphatics drain to the front of the body. As a result there are no lymph nodes in the back.

Question 24

Where can primary ossification centers be found on vertebrae?

Answer 24

Primary ossification centers at the center of the vertebral body and on the laminae.

Question 25

Where can secondary ossification centers be found on vertebrae?

Answer 25

Secondary ossification centers are found at the edges of the vertebral body and at the edges of each process of the vertebral arch.

Question 26

When do secondary ossification centers typically fuse?

Answer 26

Secondary ossification centers typically fuse in late teens.

Question 27

What are some anomalies of the vertebral column?

Answer 27

At times a wedge vertebra can result from spontaneous stop of growth in some people at the vertebrae.
Vertebrae may also fuse.

Question 28

What are the 2 types of spina bifida?

Answer 28

Spina bifida occulta (2% of population)

Spina bifida cystica (0.1%) (aka meningocele or meningomyelocele)

Question 29

What do meningomyeloceles contain?

Answer 29

Meningomyelocele contains neural tissue

Question 30

What embryological structure is the nucleus pulposus derived from?

Answer 30

Nucleus pulposus is a remnant of the notochord.

Question 31

What is the annulus fibrosus made of?

Answer 31

Fibrocartilage.

Question 32

What happens to the nucleus pulposus with age?

Answer 32

Nucleus becomes more fibrous with age and can start to split/fissure.

Question 33

Why does twisting while lifting increase the danger of a disk prolapse?

Answer 33

Annulus is arranged in layers each layer is perpendicular to the one underneath it. For this reason twisting is dangerous (50% of fibers are facing the right direction to resist the force when twisting.)