Exam I Embrology of the Vertebral Column

Question 1

when does gastrulation occur or a 3-layered embryo form

Answer 1

third week in utero

Question 2

invagination of the 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 embryonic structure gives rise to the somites

Answer 4

paraxial mesoderm

Question 5

name the areas of cellular differentiation formed within the somite

Answer 5

sclerotome, myotome and dermatome

Question 6

what are the names of the successive vertebral columns formed during development

Answer 6

membranous, cartilaginous, skeletal or osseous

Question 7

migration of somite pair to surround the notochord forms what developmental feature

Answer 7

the pericordal blastema

Question 8

the perichordal blastema gives rise to what processes

Answer 8

neural processes and costal processes

Question 9

what is the name of the artery located between adjacent perichordal blastema

Answer 9

intersegmental artery

Question 10

what forms between the sclerotomites of a pericordal blastema

Answer 10

the intersclerotomal fissure (fissure of von Ebner)

Question 11

the intersclerotomal fissure (fissure of von Ebner) gives rise to what developmental feature

Answer 11

the perichordal disc

Question 12

the union of a dense caudal sclerotomite and loose cranial sclerotome from adjacent perichordal blastema gives rise to what feature

Answer 12

the vertebral blastema

Question 13

what vessels will be identified adjacent to the vertebral blastema

Answer 13

beginning in the 6th embryonic week

Question 14

what is the name given to the replacement of mesoderm by cartilage

Answer 14

chondrofication

Question 15

what are the names given to centers of chondrofication within the vertebral blastema

Answer 15

centrum center, neural arch center, transverse process center

Question 16

how many centers of chondrification typically appear in the vertebral blastema

Answer 16

six…2 for the centrum, 2 for neural arches, 2 for transverse process

Question 17

when does the embryonic disc form

Answer 17

second week in utero

Question 18

what is the name given to the centers of ossification based on their time of appearance

Answer 18

primary centers appear in utero, secondary centers appear after birth

Question 19

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

Answer 19

during the 7th embryonic week

Question 20

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

Answer 20

3 primary to 5 secondary

Question 21

what are the name given the primary centers of ossification for a typical vertebra

Answer 21

centrum centers and neural arch centers

Question 22

what are the names/locations of the five secondary centers of ossification for a typical vertebra

Answer 22

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

Question 23

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

Answer 23

during puberty, typically ages 11-16