Development

Question 1

How many vertebrae are in the adult vertebral column?

Answer 1

33 vertebrae.

Question 2

How many presacral (true) vertebrae are there in the adult vertebral column?

Answer 2

24 presacral vertebrae.

Question 3

What are the primary curvatures of the vertebral column?

Answer 3

• Thoracic
• Sacral/coccygeal

Question 4

What are the secondary curvatures of the vertebral column?

Answer 4

• Cervical
• Lumbar

Question 5

What curvature shape does the vertebral column take in a fetus?

Answer 5

C-shaped.

Question 6

What is kyphosis commonly referred to as?

Answer 6

Hunchback deformity.

Question 7

What is lordosis commonly referred to as?

Answer 7

Swayback deformity.

Question 8

What is scoliosis defined as?

Answer 8

Lateral deviation of greater than 10 degrees.

Question 9

What is the term used to describe the ossification process of the vertebral centra?

Answer 9

True endochondral ossification.

Question 10

When does ossification of the centra first appear?

Answer 10

Between 9-10 fetal weeks.
T10-L1

Question 11

What initiates the ossification of the neural arches?

Answer 11

Muscle contraction in response to gasp reflex.

Question 12

At what age does fusion of the neural arches commence?

Answer 12

During the first year of life.
at spinous process first

Question 13

What is the neurocentral junction?

Answer 13

Fusion between the neural arches and the centra.

Question 14

What are the primary ossification centers in the atlas (C1)?

Answer 14

Three primary centers.
2x lateral masses (7th week iu)
Anterior arch (1-2 yrs)

Question 15

At what age does the posterior arch of the atlas usually fuse?

Answer 15

4-5 years.

Question 16

When does the dens fuse with the neural arches?

Answer 16

Between 3-4 years.

Question 17

How many secondary centers of ossification are there in the axis (C2)?

Answer 17

Five secondary centers.

Question 18

What do typical cervical vertebrae develop from?

Answer 18

Three centers.

Question 19

When does neurocentral fusion in cervical vertebrae complete?

Answer 19

Between 3-4 years.

Question 20

What is the sacrum’s ossification pattern represented by?

Answer 20

21 separate centers.

Question 21

When does sacral fusion typically occur?

Answer 21

Between 2-6 years.

Question 22

What is the appearance and fusion summary for the lumbar vertebrae?

Answer 22

Develop in accordance with the general ossification pattern for a typical vertebra.

Question 23

What age marks the appearance of the secondary centers in the typical cervical vertebrae?

Answer 23

Beginning of puberty.

Question 24

When is the sacroiliac joint formed?

Answer 24

Forms in the 2nd-7th intrauterine month.

Question 25

Each coccygeal vertebra forms from how many separate centers?

Answer 25

A single separate center.

Question 26

When does Co1 appear?

Answer 26

Between late fetal period and first year of life.

Question 27

What is the significance of the intervertebral disc in vertebral curvature development?

Answer 27

Modifies the shape of the vertebral column.

Question 28

What causes ring shaped ossification of centra

Answer 28

delayed vascular penetration of notochord due to angiogenic inhibiting factors

Question 29

where does ossification of neural arches begin

Answer 29

inner surface of each hemi-arch

Question 30

what is the ossification process of neural arches

Answer 30

intramembranous then endochondral

Question 31

what is the ossification timeline of the neural arches

Answer 31

primary appears at 2nd iu month in Lower C/Upper T region secondary at 3rd iu month, Lower T/upper L region bidirectional progression

Question 32

order of neurocentral fusion

Answer 32

lumbar 1st cervical 2nd thoracic 3rd

Question 33

when does anterior neurocentral junctions of C1 fuse

Answer 33

5-6 years.

Question 34

Name the 5 primary ossification centres of C2

Answer 34

2 neural arches one for true centrum 2 for each side of dens

Question 35

C2 ossification timeline

Answer 35

neural arches - 7-8 weeks true centrum - 4-5 months dens - 4-5 months

Question 36

Describe the formation of C2 articular facets

Answer 36

superior - medial 1/3 from dens -lateral 2/3 from neural arch inferior - neural arch 100%

Question 37

Axis fusion timeline

Answer 37

Dentocentral junction and neurocentral junctions at 4-6 years all lines gone by 9-10 years

Question 38

describe the os terminale

Answer 38

small ossific nodule, fills apical cleft fuses with dens at 12 years

Question 39

Describe secondary ossification of C2

Answer 39

5 centres 6 if os terminale considered epiphyseal

Question 40

describe cervical vertebrae secondary ossification

Answer 40

6 centres 2x T process 2x spinous process 1x sup annular ring 1x inf annular ring appear at puberty, begin fusion at 18, complete by 24

Question 41

describe the sacrums primary ossification pattern

Answer 41

3 months - S1&2 centra 4 months - S3&4 centra plus S1-3 neural arches 5 months - S5 centra & S4-5 neural arches 6-8 months - S1-3 paired costal elements