Embryology Development Of Vertebral Columns

Question 1

How many pairs of somites are in an embryo ?

Answer 1

42

Question 2

Where do the somites develop from ?

Answer 2

Paraaxial mesoderm

Question 3

Where does the para axial mesoderm develop from

Answer 3

Intraembryonic Mesoderm

Question 4

What part of the somite does the vertebral column develop from ?

Answer 4

Sclerotome

Question 5

During which week do the Sclerotome cells migrate to form the future vertebrae?

Answer 5

4th week

Question 6

Where do Sclerotome cells migrate to ?

Answer 6

Around the neural tube/spinal cord and the notochord to merge with the opposing somite

Question 7

Loosely arranged cells are found in which segment ?

Answer 7

Cranial segment

Question 8

Condensed tissue is found in which segment ?

Answer 8

Caudal segment

Question 9

——————-It occurs when the caudal half of the sclerotome above grows
down & fuses with the cephalic half of the sclerotome below.

Answer 9

Resegmentation

Question 10

Which structure bridges the
intervertebral discs?

Answer 10

Myotomes

Question 11

Which structure is trapped between 2 Sclerotomes due to resegmenation?

Answer 11

Intersegmental Arteries

Question 12

What forms the intervertebral discs ?

Answer 12

Mesenchymal cells between the caudal & cephalic parts of the original
sclerotome segment do not proliferate but fill the space between two
precartilaginous vertebral bodies and form the Intervertebral disc.

Question 13

What is found between the pre cartilaginous vertebrae?

Answer 13

Mesenchymal cells/ annulus fibrosis and nucleus pulposus

Question 14

What is the nucleus pulposus ?

Answer 14

Remnants of the notochord

Question 15

What is annulus fibrosis develop from

Answer 15

Mesenchyme cells from between the caudal & cephalic parts of the original
sclerotome segment

Question 16

Which week does the cartilaginous stage of development occur ?

Answer 16

6th - 8th

Question 17

chondrification centers appear in each
mesenchymal vertebra when ?

Answer 17

6th week

Question 18

Primary ossification centers appear during the?

Answer 18

8th week IUL

Question 19

When do secondary ossification centres appear ?

Answer 19

After puberty (5 of them )

Question 20

Total duration of ossification ?

Answer 20

Embryonic period (8th week) until 25 years of age

Question 21

Primary curvatures:

Answer 21

Thoracic and sacral

Question 22

Secondary curvatures :

Answer 22

Cervical (holding head up)
Lumbar (walking)

Question 23

Gene responsible
for the proper orientation of the vertebrae in the
cranio-caudal direction?

Answer 23

HOX

Question 24

What is the gene found to play an essential role in anterior-posterior development,
the ventral neural tube and somite patterning.

Answer 24

SHH

Question 25

two successive vertebrae fuse asymmetrically or have half a vertebra missing.

Answer 25

Scoliosis

Question 26

Syndrome with reduced mobility
and a short neck due to fused cervical vertebrae

Answer 26

Klippel–Feil Syndrome

Question 27

imperfect fusion
or complete Non-fusion of the two halves of vertebral arches.

Answer 27

Spina Bifida/Cleft Vertebra

Question 28

vertebrae slip
forward about the vertebral column

Answer 28

Congenital spondylolisthesis