OsteoMenagerie 7: The Vertebrae

Word on the street is that the third polar vortex will hit Michigan later this week. After trudging through this year’s record amounts of snowfall, shivering angrily at the bus stop while the temperature experiments with establishing its true seasonal nadir (-20˚C? Nah, let’s live a little. Aim for -30!), and staring forlornly out the window, pining for the sun, I am ready for a break. In the spirit of truly throwing in the towel until spring hits, I’m dedicating this week to the easiest of osteomenageries: the vertebrae.

Admittedly, I’ve already discussed how easy it is to identify categories of vertebrae by using the superior articular facets. However, if you want to quickly identify whether an isolated vertebra is cervical, thoracic or lumbar,  have I got a trick for you. We’ll start low and work our way up.

1. Lumbar vertebrae look like moose. Orient the vertebra so that the spinous process is facing you, and the superior articular facets are up (as if the vertebrae were in anatomical position in the spine of someone standing immediately in front of you).

Left: Lumbar vertebra, posterior view
Right: Moose, disgruntled view

See? It’s now impossible to unsee. The superior articular facets look like moose antlers, while the purportedly “hatchet-shaped” spinous process is inarguably a large, clunky moose nose.

Left: Lumbar Vertebra, Lateral View Right: Moose, Contented View

Left: Lumbar vertebra, lateral view
Right: Moose, contented view

2. Thoracic vertebrae resemble giraffes. The superior articular facets are both positioned so that they face straight back posteriorly, and are relatively evenly spaced and flat….much like the horns of a giraffe.

Left: Thoracic vertebra Right: Bemused giraffe

Left: Thoracic vertebra
Right: Bemused giraffe

The transverse processes are short and flare laterally, just like giraffe ears. Similarly, the spinous process of the thoracic vertebrae is much thinner and more gracile than that of the lumbar vertebrae, making it look far-more giraffe-like in lateral view:

Left: Thoraric vertebra, lateral view Right: Giraffe, longing for summer

Left: Thoraric vertebra, lateral view
Right: Giraffe, longing for summer

3. The cervical vertebrae look like extremely happy fish. Admittedly, this one is a little bit more of a stretch, but if you orient the cervical vertebrae so that the transverse foramina are highest up, while the spinous process points down (basically the position you would be in if you were behind someone, staring straight down their spinal cord while hovering above their head), you’ll see it. In this position, the transverse foramina resemble eyes, the superior articular facets resemble pectoral fins, and the spinous process looks like a pelvic fin. As a caveat, this only works for C3-C7. C1 and C2, the atlas and axis, are structurally distinct from the ‘regular’ cervicals because of their articulation with each other and with the occipital bone.

Left: Puffer fish, unpuffed Right: Cervical vertebra, superior view

Left: Puffer fish, unpuffed
Right: Cervical vertebra, superior view

Another easy way to identify the cervical vertebrae is that they tend to be the only vertebrae that have bifurcated spinous processes. They are also unique in their transverse foramina, which accommodate the vertebral vein and artery.

Transverse foramina indicated with blue arrows. Bifurcated spinous process indicated with red arrows.

Transverse foramina indicated with blue arrows. Bifurcated spinous process indicated with red arrows.

Alright. That was your osteology lesson for this week. I’m now going to curl up in bed, pull the blankets over my head, and stare at this photo of a hippopotamus getting a birthday cake until spring arrives.

Image Credits: Lumbar in posterior view here, associated moose here. Lumbar in lateral view here, associated moose here. Thoracic in posterior view here, associated giraffe here. Thoracic in lateral view here, associated giraffe here. Happy fish here, cervical in posterior view here. Cervical with birfurcated spinous process found here.

Advertisements
This entry was posted in Osteology, OsteoMenagerie, Vertebrae and tagged , , , , . Bookmark the permalink.

7 Responses to OsteoMenagerie 7: The Vertebrae

  1. That hippo cake is amazing!

    Like

  2. Terry says:

    I was searching for some images to deepen my understanding of vertebrae for a shiatsu qualification when i stumbled across your site. Just to keep the theme, the weather as I write this in England is mild with birdsong all around me, and the swallows have arrived from Africa.
    This post is just lovely – thank you so much! I hope spring has arrived for you too by now! x

    Like

    • JB says:

      Hi Terry,
      Just saw this! Glad you found the post useful. I gave up on spring in Michigan and headed for Spain instead. So far it has been a good choice. Hope your shiatsu qualification went well!

      Like

  3. Pingback: Bone Broke Year in Review | Bone Broke

  4. Maddie Williamson says:

    Hi,

    I love this site and your blog. I am a TA for an anthropological osteology class and find that your blog and explanations help me to better explain how to identify bones and features easier. Thank you so much.

    Like

  5. Pingback: Anthropology Teaching Tips: Playdoh | Bone Broke

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s