Two questions about the vertebrae:

[Da123]

I have two questions about the vertebrae:

1) Are the Accessory process and Mammillary process - unique for the lumbar vertebrae or they appear in the rest of vertebrae (cervical, thoracic).?

 

2) Is there any place (I mean site, page) or table that presents the differences between the types of vertebrae?

Edited November 4, 2015 by Da123

[Function]

You wouldn't surprise me if you told me you're going to take exam in 2 weeks students in the first year in medicine in our university are, and these are questions they frequently ask us... Which is why I'm answering these questions so thoroughly. Well ... that, and because I can answer them. If you happen to be a student from Ghent, forgive me for giving the anatomical terms in English, but I expect it to be no problem for you to translate them into Latin. If you're not, forgive me this small introduction, being completely irrelevant to you.

 

Now let me return on-topic and answer your questions:

 

(1) The mamillary and accessory processes are indeed very typical for the lumbar vertebrae, but also happen to appear on the twelfth thoracic vertebra. Under no normal circumstances are they found in cervical and other thoracic vertebrae.

 

(2) Being an undergraduate teaching assistant in anatomy (mostly osteology), let me give you an overview of typical structures per vertebra, with which you can easily distinguish the types of vertebrae from one another:

• Cervical
  • Transverse process possess 2 tubercles and seems 'split': an anterior tubercle (NB called the carotid tubercle in C6) and a posterior tubercle, divided by a groove for the spinal nerve (sulcus nervi spinalis)
  • Transverse foramen in the transverse processes (for passage of both vertebral arteries)
  • Split spinous process
  • Upstanding lateral ridges of the vertebral body, called the uncinate processes
• Thoracic
  • Superior and inferior (excl. T12) costal pit
  • Costal pit of the transverse process (excl. T11, T12)
  • Sharp, unsplit spinous process
• Lumbar
  • Very obvious, stumpy, almost rectangular spinous process
  • No superior, nor inferior costal pit
  • No costal pit on the transverse process, which is here called a costal process
  • Very broad vertebral body
  • Mammillary and accessory processes

It may be a challenge to distinguish a random lumbar vertebra from the twelfth thoracic vertebra. To distinguish them from one another, you must keep in mind that the twelfth thoracic vertebra stil possesses a superior costal pit, yet no inferior pit, nor a costal pit of the transverse process (which also isn't found on the eleventh thoracic vertebra, btw, since the eleventh and twelfth ribs (the floating ribs, costae fluctuantes) don't have a costal tubercle which can articulate with a costal pit of a transverse process).

 

There you go! Best of luck with the rest of your studying and perhaps even good luck with your exam.

 

Function

 

Sources: Sobotta, Atlas of Human Anatomy - General Anatomy and Musculoskeletal System (for solving my doubts on vertebra T12) & a hopefully credible experience as an undergraduate teaching assistant in anatomy (for all the other stuff)

Edited December 5, 2015 by Function