Exam 1 - Basic Embryology of the Vertebral Column Flashcards
What are the 3 layers of the embryo called?
Ectoderm
Mesoderm
Endoderm
Invagination of ectoderm along the primitive streak gives rise to what embryonic structure?
notochord
What is the name given to the mesoderm that will give rise to the vertebral column?
paraxial mesoderm
What does paraxial mesoderm give rise to that will form the vertebral column?
somites
Name the areas of cellular differentiation formed within the somite
sclerotome
myotome
dermatome
What part of the somite will give rise to the vertebral column?
sclerotome
List, in order, the names of the sccussive vertebral columns formed during development?
membranous
cartilaginous
osseous
Migration of sclerotomes to surround the notochord forms what developmental feature?
the perichordal blastema
The perichordal blastema gives rise to what processes?
Neural processes
costal processes
What is the name of the artery located between adjacent perichordal blastemae?
intersegmental artery
Cell proliferation within the perichordal blastema will result in what feautres?
a loose cranial sclerotomite
a dense caudal sclerotomite
What forms between the sclerotomites of a perichordal blastema?
the intrasclerotomal fissure (fissure of von Ebner)
What is the earliest embryonic feature that will identify the position of the adult intervertebral disc?
the intrasclerotomal fissure (fissure of von Ebner)
The union of a dense caudal sclerotomite and a loose cranail sclerotomite from adjacent blastemae gives rise to what feature?
the vertebral blastema
What vessel will be identified adjacent to the vertebral blastema?
the segmental artery
What is the name given to the replacement of mesoderm by cartilage?
chondrification
Chodrification begins in which region of the embryonic vertebral column?
the cervical region
What are the names given to the centers of chondrification within the vertebral blastema?
centrum center
neural arch center
transerse process center
How man centers of chondrification typically appear in the vertebral blastema
6 total
2 for the centrum
2 for the neural arch
2 for each transverse process
What is the earliest time that centers of ossification appear in the cartilaginous vertebra?
during the 7th embryonic week
What is the ratio of primary to secondary centers of ossification for a typical vertebra?
3 primary centers : 5 secondary centers
What are the names of the primary centers of ossificationfor a typical vertebra?
centrum centers
neural arch centers
What is the classification of the join forming between primary centers of ossification?
cartilage synchondrosis / amphiarthrosis synchondrosis
What are the names of the synchondroses forming between primary centers of ossification in the typical vertebra?
neurocentral synchondrosis
neural arch synchondrosis
What are the names of the five secondary centers of ossification for a typical vertebra?
tip of the transverse process
tip of the spinous process
epiphyseal plate centers
How many secondary centers of ossification appear in the typical vertebra?
5 total
1 for for the tip of each transverse process
1 for the tip of the spinous process
1 for each epiphyseal plate
What is the classification of the joint forming between secondary centers of ossification and the rest of the typical vertebra?
cartilage synchondrosis / amphiarthrosis synchondrosis
What are the names of the synchondroses forming between secondary centers of ossification and the rest of the typical vertebra?
tip of the transverse process synchondrosis
tip of the spinous process synchondrosis
epiphyseal ring synchondrosis
What is the range of appearance for secondary centers of ossification of a typical vertebra?
during puberty, typically 11 - 16 years old
