Exam 1 - Basic Embryology of the Vertebral Column

Question 1

What are the 3 layers of the embryo called?

Answer 1

Ectoderm
Mesoderm
Endoderm

Question 2

Invagination of ectoderm along the primitive streak gives rise to what embryonic structure?

Answer 2

notochord

Question 3

What is the name given to the mesoderm that will give rise to the vertebral column?

Answer 3

paraxial mesoderm

Question 4

What does paraxial mesoderm give rise to that will form the vertebral column?

Answer 4

somites

Question 5

Name the areas of cellular differentiation formed within the somite

Answer 5

sclerotome
myotome
dermatome

Question 6

What part of the somite will give rise to the vertebral column?

Answer 6

sclerotome

Question 7

List, in order, the names of the sccussive vertebral columns formed during development?

Answer 7

membranous
cartilaginous
osseous

Question 8

Migration of sclerotomes to surround the notochord forms what developmental feature?

Answer 8

the perichordal blastema

Question 9

The perichordal blastema gives rise to what processes?

Answer 9

Neural processes

costal processes

Question 10

What is the name of the artery located between adjacent perichordal blastemae?

Answer 10

intersegmental artery

Question 11

Cell proliferation within the perichordal blastema will result in what feautres?

Answer 11

a loose cranial sclerotomite

a dense caudal sclerotomite

Question 12

What forms between the sclerotomites of a perichordal blastema?

Answer 12

the intrasclerotomal fissure (fissure of von Ebner)

Question 13

What is the earliest embryonic feature that will identify the position of the adult intervertebral disc?

Answer 13

the intrasclerotomal fissure (fissure of von Ebner)

Question 14

The union of a dense caudal sclerotomite and a loose cranail sclerotomite from adjacent blastemae gives rise to what feature?

Answer 14

the vertebral blastema

Question 15

What vessel will be identified adjacent to the vertebral blastema?

Answer 15

the segmental artery

Question 16

What is the name given to the replacement of mesoderm by cartilage?

Answer 16

chondrification

Question 17

Chodrification begins in which region of the embryonic vertebral column?

Answer 17

the cervical region

Question 18

What are the names given to the centers of chondrification within the vertebral blastema?

Answer 18

centrum center
neural arch center
transerse process center

Question 19

How man centers of chondrification typically appear in the vertebral blastema

Answer 19

6 total
2 for the centrum
2 for the neural arch
2 for each transverse process

Question 20

What is the earliest time that centers of ossification appear in the cartilaginous vertebra?

Answer 20

during the 7th embryonic week

Question 21

What is the ratio of primary to secondary centers of ossification for a typical vertebra?

Answer 21

3 primary centers : 5 secondary centers

Question 22

What are the names of the primary centers of ossificationfor a typical vertebra?

Answer 22

centrum centers

neural arch centers

Question 23

What is the classification of the join forming between primary centers of ossification?

Answer 23

cartilage synchondrosis / amphiarthrosis synchondrosis

Question 24

What are the names of the synchondroses forming between primary centers of ossification in the typical vertebra?

Answer 24

neurocentral synchondrosis

neural arch synchondrosis

Question 25

What are the names of the five secondary centers of ossification for a typical vertebra?

Answer 25

tip of the transverse process
tip of the spinous process
epiphyseal plate centers

Question 26

How many secondary centers of ossification appear in the typical vertebra?

Answer 26

5 total
1 for for the tip of each transverse process
1 for the tip of the spinous process
1 for each epiphyseal plate

Question 27

What is the classification of the joint forming between secondary centers of ossification and the rest of the typical vertebra?

Answer 27

cartilage synchondrosis / amphiarthrosis synchondrosis

Question 28

What are the names of the synchondroses forming between secondary centers of ossification and the rest of the typical vertebra?

Answer 28

tip of the transverse process synchondrosis
tip of the spinous process synchondrosis
epiphyseal ring synchondrosis

Question 29

What is the range of appearance for secondary centers of ossification of a typical vertebra?

Answer 29

during puberty, typically 11 - 16 years old