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Muscular Arrangement and Muscle Attachment Sites in the Cervical Region of the American Barn Owl (Tyto furcata pratincola).

Boumans ML, Krings M, Wagner H - PLoS ONE (2015)

Bottom Line: This improved the anatomical description of the cervical region of this species.The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far.Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

View Article: PubMed Central - PubMed

Affiliation: Institute of Zoology, RWTH Aachen University, Aachen, Germany.

ABSTRACT
Owls have the largest head rotation capability amongst vertebrates. Anatomical knowledge of the cervical region is needed to understand the mechanics of these extreme head movements. While data on the morphology of the cervical vertebrae of the barn owl have been provided, this study is aimed to provide an extensive description of the muscle arrangement and the attachment sites of the muscles on the owl's head-neck region. The major cervical muscles were identified by gross dissection of cadavers of the American barn owl (Tyto furcata pratincola), and their origin, courses, and insertion were traced. In the head-neck region nine superficial larger cervical muscles of the craniocervical, dorsal and ventral subsystems were selected for analysis, and the muscle attachment sites were illustrated in digital models of the skull and cervical vertebrae of the same species as well as visualised in a two-dimensional sketch. In addition, fibre orientation and lengths of the muscles and the nature (fleshy or tendinous) of the attachment sites were determined. Myological data from this study were combined with osteological data of the same species. This improved the anatomical description of the cervical region of this species. The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far. Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

No MeSH data available.


M. splenius capitis.A) Dorsal view on M. splenius capitis of T. f. pratincola. The origin from C2 is indicated by an asterisk. The left cranial belly of the M. biventer cervicis was removed to expose the M. splenius capitis, whereas the right cranial belly of the M. biventer cervicis (bc) was left intact and flapped back cranially. From the M. splenius capitis a pars medialis (m) and a pars lateralis (l) could be distinguished and were separated by a thin fascial sheath, which is indicated by a broken line in the M. splenius capitis sinister. The M. splenius capitis inserts ventrally to the M. biventer cervicis (bc) and medially to the M. rectus capitis lateralis (rcl). Coordinate system indicates cranial (Cr), lateral (L) and caudal (Ca). Scale bar represents one centimetre. B) Dorsal view on the skull with indicated insertion sites of the M. splenius capitis, pars medialis (m) and pars lateralis (l). Foramen magnum (FM) and condylus occipitalis (CO) are indicated. Scale bar represents one millimetre (adapted from [5]). C-D) Originating muscle attachment sites of the M. splenius capitis (coloured areas) in the three-dimensional models of the vertebrae of T. f. pratincola. In D the red area represents the origin of the pars medialis and the white area the origin of the pars lateralis. View on the vertebrae (C1-C2) from lateral left; cranial is left. Scale bars in C-D represent one millimetre (adapted from: [5]). E) Connection diagram from lateral view of M. splenius capitis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips. F) Connection diagram from dorsal view of M. splenius capitis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips.
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pone.0134272.g003: M. splenius capitis.A) Dorsal view on M. splenius capitis of T. f. pratincola. The origin from C2 is indicated by an asterisk. The left cranial belly of the M. biventer cervicis was removed to expose the M. splenius capitis, whereas the right cranial belly of the M. biventer cervicis (bc) was left intact and flapped back cranially. From the M. splenius capitis a pars medialis (m) and a pars lateralis (l) could be distinguished and were separated by a thin fascial sheath, which is indicated by a broken line in the M. splenius capitis sinister. The M. splenius capitis inserts ventrally to the M. biventer cervicis (bc) and medially to the M. rectus capitis lateralis (rcl). Coordinate system indicates cranial (Cr), lateral (L) and caudal (Ca). Scale bar represents one centimetre. B) Dorsal view on the skull with indicated insertion sites of the M. splenius capitis, pars medialis (m) and pars lateralis (l). Foramen magnum (FM) and condylus occipitalis (CO) are indicated. Scale bar represents one millimetre (adapted from [5]). C-D) Originating muscle attachment sites of the M. splenius capitis (coloured areas) in the three-dimensional models of the vertebrae of T. f. pratincola. In D the red area represents the origin of the pars medialis and the white area the origin of the pars lateralis. View on the vertebrae (C1-C2) from lateral left; cranial is left. Scale bars in C-D represent one millimetre (adapted from: [5]). E) Connection diagram from lateral view of M. splenius capitis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips. F) Connection diagram from dorsal view of M. splenius capitis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips.

Mentions: Muscle characteristics: Within the M. splenius capitis in T. f. pratincola a pars lateralis and a pars medialis could be distinguished (Fig 3A). Both the pars medialis and pars lateralis originate from C2 (Fig 3A) and diverge when they run cranially before insertion on the os supraoccipitale (Fig 3A). The M. splenius capitis pars medialis is also connected with the dorsal side of the arcus vertebrae of C1 (Fig 3C, 3E and 3F). Both parts are positioned oblique in respect to the craniocaudal axis of the cervical column, and have parallel oriented fibres. The M. splenius capitis is approximately two centimetres in length, measured from the origin on C2 to the most cranial insertion site on the skull. The connection diagram from dorsal view shows the oblique course of this muscle (Fig 3F).


Muscular Arrangement and Muscle Attachment Sites in the Cervical Region of the American Barn Owl (Tyto furcata pratincola).

Boumans ML, Krings M, Wagner H - PLoS ONE (2015)

M. splenius capitis.A) Dorsal view on M. splenius capitis of T. f. pratincola. The origin from C2 is indicated by an asterisk. The left cranial belly of the M. biventer cervicis was removed to expose the M. splenius capitis, whereas the right cranial belly of the M. biventer cervicis (bc) was left intact and flapped back cranially. From the M. splenius capitis a pars medialis (m) and a pars lateralis (l) could be distinguished and were separated by a thin fascial sheath, which is indicated by a broken line in the M. splenius capitis sinister. The M. splenius capitis inserts ventrally to the M. biventer cervicis (bc) and medially to the M. rectus capitis lateralis (rcl). Coordinate system indicates cranial (Cr), lateral (L) and caudal (Ca). Scale bar represents one centimetre. B) Dorsal view on the skull with indicated insertion sites of the M. splenius capitis, pars medialis (m) and pars lateralis (l). Foramen magnum (FM) and condylus occipitalis (CO) are indicated. Scale bar represents one millimetre (adapted from [5]). C-D) Originating muscle attachment sites of the M. splenius capitis (coloured areas) in the three-dimensional models of the vertebrae of T. f. pratincola. In D the red area represents the origin of the pars medialis and the white area the origin of the pars lateralis. View on the vertebrae (C1-C2) from lateral left; cranial is left. Scale bars in C-D represent one millimetre (adapted from: [5]). E) Connection diagram from lateral view of M. splenius capitis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips. F) Connection diagram from dorsal view of M. splenius capitis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519302&req=5

pone.0134272.g003: M. splenius capitis.A) Dorsal view on M. splenius capitis of T. f. pratincola. The origin from C2 is indicated by an asterisk. The left cranial belly of the M. biventer cervicis was removed to expose the M. splenius capitis, whereas the right cranial belly of the M. biventer cervicis (bc) was left intact and flapped back cranially. From the M. splenius capitis a pars medialis (m) and a pars lateralis (l) could be distinguished and were separated by a thin fascial sheath, which is indicated by a broken line in the M. splenius capitis sinister. The M. splenius capitis inserts ventrally to the M. biventer cervicis (bc) and medially to the M. rectus capitis lateralis (rcl). Coordinate system indicates cranial (Cr), lateral (L) and caudal (Ca). Scale bar represents one centimetre. B) Dorsal view on the skull with indicated insertion sites of the M. splenius capitis, pars medialis (m) and pars lateralis (l). Foramen magnum (FM) and condylus occipitalis (CO) are indicated. Scale bar represents one millimetre (adapted from [5]). C-D) Originating muscle attachment sites of the M. splenius capitis (coloured areas) in the three-dimensional models of the vertebrae of T. f. pratincola. In D the red area represents the origin of the pars medialis and the white area the origin of the pars lateralis. View on the vertebrae (C1-C2) from lateral left; cranial is left. Scale bars in C-D represent one millimetre (adapted from: [5]). E) Connection diagram from lateral view of M. splenius capitis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips. F) Connection diagram from dorsal view of M. splenius capitis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips.
Mentions: Muscle characteristics: Within the M. splenius capitis in T. f. pratincola a pars lateralis and a pars medialis could be distinguished (Fig 3A). Both the pars medialis and pars lateralis originate from C2 (Fig 3A) and diverge when they run cranially before insertion on the os supraoccipitale (Fig 3A). The M. splenius capitis pars medialis is also connected with the dorsal side of the arcus vertebrae of C1 (Fig 3C, 3E and 3F). Both parts are positioned oblique in respect to the craniocaudal axis of the cervical column, and have parallel oriented fibres. The M. splenius capitis is approximately two centimetres in length, measured from the origin on C2 to the most cranial insertion site on the skull. The connection diagram from dorsal view shows the oblique course of this muscle (Fig 3F).

Bottom Line: This improved the anatomical description of the cervical region of this species.The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far.Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

View Article: PubMed Central - PubMed

Affiliation: Institute of Zoology, RWTH Aachen University, Aachen, Germany.

ABSTRACT
Owls have the largest head rotation capability amongst vertebrates. Anatomical knowledge of the cervical region is needed to understand the mechanics of these extreme head movements. While data on the morphology of the cervical vertebrae of the barn owl have been provided, this study is aimed to provide an extensive description of the muscle arrangement and the attachment sites of the muscles on the owl's head-neck region. The major cervical muscles were identified by gross dissection of cadavers of the American barn owl (Tyto furcata pratincola), and their origin, courses, and insertion were traced. In the head-neck region nine superficial larger cervical muscles of the craniocervical, dorsal and ventral subsystems were selected for analysis, and the muscle attachment sites were illustrated in digital models of the skull and cervical vertebrae of the same species as well as visualised in a two-dimensional sketch. In addition, fibre orientation and lengths of the muscles and the nature (fleshy or tendinous) of the attachment sites were determined. Myological data from this study were combined with osteological data of the same species. This improved the anatomical description of the cervical region of this species. The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far. Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

No MeSH data available.