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Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes
Here we examined the kinematic function of the morpho- logically unique first thoracic vertebra in giraffes. The first thoracic vertebra of the giraffe displayed similar shape to the seventh cervical vertebra in general ruminants. The flexion experiment using giraffe carcasses demonstrated that the...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society Publishing
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785981/ https://www.ncbi.nlm.nih.gov/pubmed/26998330 http://dx.doi.org/10.1098/rsos.150604 |
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author | Gunji, Megu Endo, Hideki |
author_facet | Gunji, Megu Endo, Hideki |
author_sort | Gunji, Megu |
collection | PubMed |
description | Here we examined the kinematic function of the morpho- logically unique first thoracic vertebra in giraffes. The first thoracic vertebra of the giraffe displayed similar shape to the seventh cervical vertebra in general ruminants. The flexion experiment using giraffe carcasses demonstrated that the first thoracic vertebra exhibited a higher dorsoventral mobility than other thoracic vertebrae. Despite the presence of costovertebral joints, restriction in the intervertebral movement imposed by ribs is minimized around the first thoracic vertebra by subtle changes of the articular system between the vertebra and ribs. The attachment area of musculus longus colli, mainly responsible for ventral flexion of the neck, is partly shifted posteriorly in the giraffe so that the force generated by muscles is exerted on the cervical vertebrae and on the first thoracic vertebra. These anatomical modifications allow the first thoracic vertebra to adopt the kinematic function of a cervical vertebra in giraffes. The novel movable articulation in the thorax functions as a fulcrum of neck movement and results in a large displacement of reachable space in the cranial end of the neck. The unique first thoracic vertebra in giraffes provides higher flexibility to the neck and may provide advantages for high browsing and/or male competition behaviours specific to giraffes. |
format | Online Article Text |
id | pubmed-4785981 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | The Royal Society Publishing |
record_format | MEDLINE/PubMed |
spelling | pubmed-47859812016-03-18 Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes Gunji, Megu Endo, Hideki R Soc Open Sci Biology (Whole Organism) Here we examined the kinematic function of the morpho- logically unique first thoracic vertebra in giraffes. The first thoracic vertebra of the giraffe displayed similar shape to the seventh cervical vertebra in general ruminants. The flexion experiment using giraffe carcasses demonstrated that the first thoracic vertebra exhibited a higher dorsoventral mobility than other thoracic vertebrae. Despite the presence of costovertebral joints, restriction in the intervertebral movement imposed by ribs is minimized around the first thoracic vertebra by subtle changes of the articular system between the vertebra and ribs. The attachment area of musculus longus colli, mainly responsible for ventral flexion of the neck, is partly shifted posteriorly in the giraffe so that the force generated by muscles is exerted on the cervical vertebrae and on the first thoracic vertebra. These anatomical modifications allow the first thoracic vertebra to adopt the kinematic function of a cervical vertebra in giraffes. The novel movable articulation in the thorax functions as a fulcrum of neck movement and results in a large displacement of reachable space in the cranial end of the neck. The unique first thoracic vertebra in giraffes provides higher flexibility to the neck and may provide advantages for high browsing and/or male competition behaviours specific to giraffes. The Royal Society Publishing 2016-02-03 /pmc/articles/PMC4785981/ /pubmed/26998330 http://dx.doi.org/10.1098/rsos.150604 Text en http://creativecommons.org/licenses/by/4.0/ © 2016 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. |
spellingShingle | Biology (Whole Organism) Gunji, Megu Endo, Hideki Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
title | Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
title_full | Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
title_fullStr | Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
title_full_unstemmed | Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
title_short | Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
title_sort | functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes |
topic | Biology (Whole Organism) |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785981/ https://www.ncbi.nlm.nih.gov/pubmed/26998330 http://dx.doi.org/10.1098/rsos.150604 |
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