Vertebra
Last updated
A vertebra is an irregular bone whose size varies with spinal loading, posture, and pathology.[1] Each typical vertebra has a body (centrum) and a posterior vertebral arch that surrounds the vertebral foramen.[2][3]
Key facts and history
The human vertebral column usually contains 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 fused sacral, and 4 coccygeal.[4][3] Vertebrae develop from somites in the early embryo, with sclerotome cells migrating toward the notochord.[5] At birth, a typical vertebra shows three primary ossific areas: one for the centrum and one for each half of the neural arch.[3] The body is composed of cancellous bone covered by a thin coating of cortical bone.[2]
Variation in the number of vertebrae within specific spinal sections occurs in roughly one out of every ten individuals.[4] Each vertebral body is created when the lower portion of a single sclerotome merges with the upper portion of the next sclerotome.[5] Cells from the sclerotome travel in a dorsal direction to construct the vertebral arch and in a distal direction to build the ribs.[5] These surfaces, known as vertebral endplates, function to hold the adjacent discs in place and help distribute the forces placed upon them.[6]
What the cited sources add
The InnerBody account notes that lumbar vertebrae are second in size only to the sacrum.[7] The same source states that the fifth lumbar vertebra is much larger on its front side than in the back.[7] Basic Human Anatomy explains that the margins of the upper and lower vertebral surfaces consist of a ring of compact bone called the vertebral end-plates.[3] That source also describes that the part of the lamina between the superior and inferior articular processes is the pars interarticularis, which is liable to injury.[3]
The CNN article reports that human embryos have a tail of 10 to 12 vertebrae during development.[8] Basic Human Anatomy notes that the anterior tubercles of the C6 vertebra are called the carotid tubercles.[3]
References
- Wikipedia, "Vertebra" (CC BY-SA 4.0), which cites: McGraw-Hill Science and Technology (original not read by us) en.wikipedia.org
- Wikipedia, "Vertebra" (CC BY-SA 4.0), which cites: "Chapter 39: The vertebral column", Basic Human Anatomy; Dorland's, "Dorland's Illustrated Medical Dictionary", Elsevier Saunders, 2012, p. 329; Gdyczynski, "On estimating the directionality distribution in pedicle trabecular bone from micro-CT images", Physiological Measurement, 2014, p. 2415–2428 (we also read that source) en.wikipedia.org
- "Chapter 39: The vertebral column", Basic Human Anatomy. facts only, no text reused. humananatomy.host.dartmouth.edu
- Wikipedia, "Vertebra" (CC BY-SA 4.0), which cites: Watson, "The Spinal Cord", 2009, p. 1–7; Hu, "A neglected point in surgical treatment of adolescent idiopathic scoliosis: Variations in the number of vertebrae", Medicine, August 2016; Ying-zhao, "Variation in Global Spinal Sagittal Parameters in Asymptomatic Adults with 11 Thoracic Vertebrae, four Lumbar Vertebrae, and six Lumbar Vertebrae", Orthopaedic Surgery, February 2022, p. 341–348; Ying-zhao, "Variation in Global Spinal Sagittal Parameters in Asymptomatic Adults with 11 Thoracic Vertebrae, four Lumbar Vertebrae, and six Lumbar Vertebra en.wikipedia.org
- Wikipedia, "Vertebra" (CC BY-SA 4.0), which cites: Walker, Warren F., Jr. (1987) Functional Anatomy of the Vertebrate San Francisco: Saunders College Publishing. (original not read by us) en.wikipedia.org
- Wikipedia, "Vertebra" (CC BY-SA 4.0), which cites: Muller-Gerbl, M, "The distribution of mineral density in the cervical vertebral endplates", Eur Spine J, Mar 2008, p. 432–438 (original not read by us) en.wikipedia.org
- Taylor, "Lumbar Vertebrae", InnerBody. facts only, no text reused. innerbody.com
- Weisberger, "Why don't humans have tails? Scientists find answers in an unlikely place", CNN, March 23, 2024. facts only, no text reused. cnn.com
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Vertebra (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
More in Musculoskeletal System
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Vertebra (CC BY-SA 4.0).
- Word definitions: the Codexery glossary, each quoted from its Wikipedia article.
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced