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Comparison of the Superior and Inferior Rectus Muscles in Humans: An Anatomical Study with Notes on Morphology, Anatomical Variations, and Intramuscular Innervation Patterns
Joint Authors
Haładaj, Robert
Tubbs, R. Shane
Polguj, Michał
Source
Issue
Vol. 2020, Issue 2020 (31 Dec. 2020), pp.1-9, 9 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2020-04-30
Country of Publication
Egypt
No. of Pages
9
Main Subjects
Abstract EN
A comparison of the superior and inferior rectus muscles was performed to determine whether they have similar structures and innervation attributable to their participation in the same type of, although antagonistic, eye movements.
The study was conducted on 70 cadaveric hemiheads, and the anatomical variations in the superior and inferior rectus muscles were assessed.
Sihler’s whole mount nerve staining technique was used on 20 isolated superior and 20 isolated inferior rectus muscle specimens to visualize the intramuscular distribution of the oculomotor nerve subbranches.
In two cases (~2.8%), variant muscular slips were found that connected the superior and inferior rectus muscles.
In 80% of cases, muscular branches arising directly from the inferior branch of the oculomotor nerve innervated the inferior rectus muscle, while in 20% of cases, the nerve to the inferior oblique muscle pierced the inferior rectus muscle and provided its innervation.
In 15 of 70 specimens (21.4%), a branch to the levator palpebrae superioris muscle pierced the superior rectus muscle.
The distance between the specific rectus muscle’s insertion and the anterior-most terminations of the nerves’ subbranches with reference to the muscle’s total length ranged from 26.9% to 47.2% for the inferior rectus and from 34.8% to 46.6% for the superior rectus, respectively.
The superior rectus muscle is slightly longer and its insertion is farther from the limbus of the cornea than is the inferior rectus muscle.
Both muscles share a common general pattern of intramuscular nerve subbranches’ arborization, with characteristic Y-shaped ramifications that form the terminal nerve plexus located near half of the muscles’ length.
Unexpected anatomical variations of the extraocular muscles may be relevant during orbital imaging or surgical procedures.
American Psychological Association (APA)
Haładaj, Robert& Polguj, Michał& Tubbs, R. Shane. 2020. Comparison of the Superior and Inferior Rectus Muscles in Humans: An Anatomical Study with Notes on Morphology, Anatomical Variations, and Intramuscular Innervation Patterns. BioMed Research International،Vol. 2020, no. 2020, pp.1-9.
https://search.emarefa.net/detail/BIM-1137925
Modern Language Association (MLA)
Haładaj, Robert…[et al.]. Comparison of the Superior and Inferior Rectus Muscles in Humans: An Anatomical Study with Notes on Morphology, Anatomical Variations, and Intramuscular Innervation Patterns. BioMed Research International No. 2020 (2020), pp.1-9.
https://search.emarefa.net/detail/BIM-1137925
American Medical Association (AMA)
Haładaj, Robert& Polguj, Michał& Tubbs, R. Shane. Comparison of the Superior and Inferior Rectus Muscles in Humans: An Anatomical Study with Notes on Morphology, Anatomical Variations, and Intramuscular Innervation Patterns. BioMed Research International. 2020. Vol. 2020, no. 2020, pp.1-9.
https://search.emarefa.net/detail/BIM-1137925
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1137925