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Published in: Anatomical Science International 3/2023

21-01-2023 | Review Article

Atavistic and vestigial anatomical structures in the head, neck, and spine: an overview

Authors: Siddhant Suri Dhawan, Vivek Yedavalli, Tarik F. Massoud

Published in: Anatomical Science International | Issue 3/2023

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Abstract

Organisms may retain nonfunctional anatomical features as a consequence of evolutionary natural selection. Resultant atavistic and vestigial anatomical structures have long been a source of perplexity. Atavism is when an ancestral trait reappears after loss through an evolutionary change in previous generations, whereas vestigial structures are remnants that are largely or entirely functionless relative to their original roles. While physicians are cognizant of their existence, atavistic and vestigial structures are rarely emphasized in anatomical curricula and can, therefore, be puzzling when discovered incidentally. In addition, the literature is replete with examples of the terms atavistic and vestigial being used interchangeably without careful distinction between them. We provide an overview of important atavistic and vestigial structures in the head, neck, and spine that can serve as a reference for anatomists and clinical neuroscientists. We review the literature on atavistic and vestigial anatomical structures of the head, neck, and spine that may be encountered in clinical practice. We define atavistic and vestigial structures and employ these definitions consistently when classifying anatomical structures. Pertinent anatomical structures are numerous and include human tails, plica semilunaris, the vomeronasal organ, levator claviculae, and external ear muscles, to name a few. Atavistic and vestigial structures are found throughout the head, neck, and spine. Some, such as human tails and branchial cysts may be clinically symptomatic. Literature reports indicate that their prevalence varies across populations. Knowledge of atavistic and vestigial anatomical structures can inform diagnoses, prevent misrecognition of variation for pathology, and guide clinical interventions.
Literature
go back to reference Castañeyra-Perdomo A, Carmona-Calero EM, Pérez-González H, Martínez-Peña y Valenzuela I, Plaza-Moreno P, Ormazabal-Ramos C, González-Marrero I, Trujillano-Dorado A, Ferres-Torres R (2004) Ontogenic development of the human subcommissural organ. Eur J Anat 8:107–120 Castañeyra-Perdomo A, Carmona-Calero EM, Pérez-González H, Martínez-Peña y Valenzuela I, Plaza-Moreno P, Ormazabal-Ramos C, González-Marrero I, Trujillano-Dorado A, Ferres-Torres R (2004) Ontogenic development of the human subcommissural organ. Eur J Anat 8:107–120
go back to reference Cuadra-Blanco CD, Peces-Peña MD, Carvallo-de Moraes LO, Herrera-Lara ME, Mérida-Velasco JR (2013) Development of the platysma muscle and the superficial musculoaponeurotic system (human specimens at 8–17 weeks of development). Sci World J 2013:1–8. https://doi.org/10.1155/2013/716962CrossRef Cuadra-Blanco CD, Peces-Peña MD, Carvallo-de Moraes LO, Herrera-Lara ME, Mérida-Velasco JR (2013) Development of the platysma muscle and the superficial musculoaponeurotic system (human specimens at 8–17 weeks of development). Sci World J 2013:1–8. https://​doi.​org/​10.​1155/​2013/​716962CrossRef
go back to reference Davson H (2012) in: the eye Pt Ia. Elsevier Science, Burlington, p 85 Davson H (2012) in: the eye Pt Ia. Elsevier Science, Burlington, p 85
go back to reference Oksche A (1993) The subcommissural organ an ependymal brain gland. Springer, BerlinCrossRef Oksche A (1993) The subcommissural organ an ependymal brain gland. Springer, BerlinCrossRef
go back to reference Remington LA (2014) Clinical anatomy of the visual system. Elsevier Health Sciences, Saint Louis Remington LA (2014) Clinical anatomy of the visual system. Elsevier Health Sciences, Saint Louis
go back to reference Rubinstein D, Escott EJ, Henrick LL (1999) The prevalence and CT appearance of the Levator claviculae muscle: a normal variant not to be mistaken for an abnormal. Am J Neuroradiol 20(4):583–586PubMedPubMedCentral Rubinstein D, Escott EJ, Henrick LL (1999) The prevalence and CT appearance of the Levator claviculae muscle: a normal variant not to be mistaken for an abnormal. Am J Neuroradiol 20(4):583–586PubMedPubMedCentral
go back to reference Schmalfuß L, Rupp R, Tuga MR, Kogut A, Hewitt M, Meincke J, Klinker F, Duttenhoefer W, Eck U, Mikut R, Reischl M, Liebetanz D (2015) Steer by ear: myoelectric auricular control of powered wheelchairs for individuals with spinal cord injury. Restor Neurol Neurosci 34:79–95. https://doi.org/10.3233/rnn-150579CrossRef Schmalfuß L, Rupp R, Tuga MR, Kogut A, Hewitt M, Meincke J, Klinker F, Duttenhoefer W, Eck U, Mikut R, Reischl M, Liebetanz D (2015) Steer by ear: myoelectric auricular control of powered wheelchairs for individuals with spinal cord injury. Restor Neurol Neurosci 34:79–95. https://​doi.​org/​10.​3233/​rnn-150579CrossRef
go back to reference Smith HF, Wright W (2018) Vestigial organ. Encyclopedia of animal cognition and behavior. Springer, Berlin Smith HF, Wright W (2018) Vestigial organ. Encyclopedia of animal cognition and behavior. Springer, Berlin
go back to reference Toerien MJ, Gous AE (1978) The orbital muscle of Müller. S Afr Med J 53:139–141 Toerien MJ, Gous AE (1978) The orbital muscle of Müller. S Afr Med J 53:139–141
go back to reference Tubbs RS, Shoja MM, Loukas M (2016b) In Bergman’s comprehensive encyclopedia of human anatomic variation. Wiley Blackwell, Hoboken, p 222CrossRef Tubbs RS, Shoja MM, Loukas M (2016b) In Bergman’s comprehensive encyclopedia of human anatomic variation. Wiley Blackwell, Hoboken, p 222CrossRef
go back to reference Vasileiadis I, Kapetanakis S, Petousis A, Stavrianaki A, Fiska A, Karakostas E (2012) Internal laryngopyocele as a cause of acute airway obstruction: an extremely rare case and review of the literature. Acta Otorhinolaryngol Ital 32(1):58–62PubMedPubMedCentral Vasileiadis I, Kapetanakis S, Petousis A, Stavrianaki A, Fiska A, Karakostas E (2012) Internal laryngopyocele as a cause of acute airway obstruction: an extremely rare case and review of the literature. Acta Otorhinolaryngol Ital 32(1):58–62PubMedPubMedCentral
go back to reference Verhaeghe J, Gheysen R, Enzlin P (2013) Pheromones and their effect on women’s mood and sexuality. Facts, Views, and Vision ObGyn 5:189–195 Verhaeghe J, Gheysen R, Enzlin P (2013) Pheromones and their effect on women’s mood and sexuality. Facts, Views, and Vision ObGyn 5:189–195
go back to reference Walia I, Arora HS, Barker EA, Delgado RM 3rd, Frazier OH (2010) Snake heart: a case of atavism in a human being. Tex Heart Inst J 37(6):687–690PubMedPubMedCentral Walia I, Arora HS, Barker EA, Delgado RM 3rd, Frazier OH (2010) Snake heart: a case of atavism in a human being. Tex Heart Inst J 37(6):687–690PubMedPubMedCentral
go back to reference West-Eberhard MJ (2013) In: Developmental plasticity and evolution. Oxford University Press, New York, p 235 West-Eberhard MJ (2013) In: Developmental plasticity and evolution. Oxford University Press, New York, p 235
go back to reference Wiedersheim R (1895) The structure of man. MacMillan, London Wiedersheim R (1895) The structure of man. MacMillan, London
go back to reference Wright CG (1997) Development of the human external ear. J Am Acad Audiol 8(6):379–382PubMed Wright CG (1997) Development of the human external ear. J Am Acad Audiol 8(6):379–382PubMed
Metadata
Title
Atavistic and vestigial anatomical structures in the head, neck, and spine: an overview
Authors
Siddhant Suri Dhawan
Vivek Yedavalli
Tarik F. Massoud
Publication date
21-01-2023
Publisher
Springer Nature Singapore
Published in
Anatomical Science International / Issue 3/2023
Print ISSN: 1447-6959
Electronic ISSN: 1447-073X
DOI
https://doi.org/10.1007/s12565-022-00701-7

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