Vertebral Column/Spinal Column Flashcards
What is the number of vertebrae in a typical adolescent?
33 segments
What is the number of vertebrae in a typical adult?
26 segments
What constitutes the spine?
The 24 presacral segments; the cervical, thoracic and lumbar vertebrae
Which mammals have more than seven cervical vertebrae?
The ant bear and the three-toed sloth
Which mammals have less than seven cervical vertebrae?
The manatee and two-toed sloth
What does the term “cervical” refer to?
The region of the neck
What does the term “thoracic” refer to?
Breast plate or chest; it referred to the armor bearing region of the torso
What other term is often used to identify the vertebral segments of the chest?
The dorsal segments; the dorsals
What does the term “lumbar” refer to?
The loin; the region between the rib and the hip
What does the term “sacrum” refer to?
The holy bone or holy region
What does the term “coccyx” refer to?
A cuckoo birds’ bill or cuckoo birds’ beak
What is the length of a typical male spinal column?
About 70 cm or 28 in
What is the length of a typical female spinal column?
About 60 cm or 25 in
What is the length difference between a typical male and typical female spinal column?
about 3 in
What is the length of the male cervical region?
about 12 cm or 5 in.
What is the length of the male thoracic region?
About 28 cm or 11 in
What is the length of the male lumbar region?
About 18cm or 7 in
What is the length of the male sacrum?
About 12 cm or 5 in
Based on the numbers for individual regions of the vertebral column, what is the length of the male spine?
About 58 cm or 23 in.
How does the vertebral column participate in skeletal formation?
Ribs are formed from the costal process of the embryonic vertebral template.
What levels of the vertebral column specifically accommodate weigh-bearing transfer?
S1-S3 at the auricular surface.
What is specifically responsible for shape and position of the human frame?
Comparative anterior vs. posterior height of the vertebral body and comparative anterior vs. posterior height of the intervertebral disc.
What organs is specifically associated with the horizontal axis of the skull?
The eye and the vestibular apparatus of the inner ear.
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.
Name the areas of cellular differentiation formed within the somite.
sclerotome, myotome, dermatome
What are the names of the successive vertebral columns formed during development?
membranous, cartilaginous, skeletal/osseous
Migration of a somite pair to surround the notochord forms what developmental feature?
The perichordal blastema
The perichordal blastema gives rise to what processes?
the neural processes and costal processes
What is the name of the artery located between adjacent perichordal blastema?
Intersegmental artery
What forms between the sclerotomites of a perichordal blastema?
The intrasclerotomal fissure of von Ebner
The intrasclerotomal fissure of von Ebner gives rise to what developmental feature?
The perichordal disc
The union of a dense caudal sclerotomite and a loose cranial sclerotomite from adjacent perichordal blastemae gives rise to what feature?
The vertebral blastema
What vessel will be identified adjacent to the vertebral blastema?
The segmental artery
When will cartilage first form in the membranous vertebral blastema?
Beginning in the 6th embryonic week
What is the name given to the replacement of mesoderm by cartilage?
Chondrification
How many centers of chondrification typically appear in the vertebral blastema?
Six
- 2 for the centrum
- 2 for the neural arches
- 2 for each transverse process
What is the earliest time that centers of ossification appear in the cartilaginous vertebrae?
During the 7th embryonic week
What is the name given to centers of ossification based on time of appearance?
Primary centers appear in utero, secondary centers appear after birth
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 ossification for a typical vertebra?
Centrum centers and neural arch centers
What are the names/locations of the five secondary centers of ossification for a typical vertebra?
tip of the transverse process, tip of the spinous process, epiphyseal plate centers
What is the range of appearance for secondary centers of ossification of typical vertebra?
During puberty, typically ages 11-16 years old.
