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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. longus colli dorsalis, pars cranialis.A) Dorsal view on M. longus colli dorsalis, pars cranialis. Vertebrae numbers are indicated (C2-C7). The slips from the pars cranialis insert to the tendo axialis (ta) from a pars caudalis (ca) slip. The lateral processus of C2, which serve as insertion point for the tendo axialis are indicated with broken lines. The M. interspinalis (is), M. splenius capitis (sc) and M. longus colli dorsalis, pars profunda (pr) are indicated for reference. Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B-G) Muscle attachment sites of the M. longus colli dorsalis, pars cranialis indicated with red circles in the three-dimensional models of the vertebrae of T. f. pratincola from dorsal view (cranial is on top). Scale bars in B-G represent one millimetre (adapted from [5]). H) Connection diagram from lateral view of M. longus colli dorsalis, pars cranialis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips, broken lines represent the tendo axialis. The arrowhead indicates that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally. I) Connection diagram from dorsal view of M. rectus capitis ventralis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips. Broken lines indicate the tendo axialis. The arrowheads indicate that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally.
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pone.0134272.g009: M. longus colli dorsalis, pars cranialis.A) Dorsal view on M. longus colli dorsalis, pars cranialis. Vertebrae numbers are indicated (C2-C7). The slips from the pars cranialis insert to the tendo axialis (ta) from a pars caudalis (ca) slip. The lateral processus of C2, which serve as insertion point for the tendo axialis are indicated with broken lines. The M. interspinalis (is), M. splenius capitis (sc) and M. longus colli dorsalis, pars profunda (pr) are indicated for reference. Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B-G) Muscle attachment sites of the M. longus colli dorsalis, pars cranialis indicated with red circles in the three-dimensional models of the vertebrae of T. f. pratincola from dorsal view (cranial is on top). Scale bars in B-G represent one millimetre (adapted from [5]). H) Connection diagram from lateral view of M. longus colli dorsalis, pars cranialis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips, broken lines represent the tendo axialis. The arrowhead indicates that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally. I) Connection diagram from dorsal view of M. rectus capitis ventralis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips. Broken lines indicate the tendo axialis. The arrowheads indicate that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally.

Mentions: Origin and insertion: The M. longus colli dorsalis, pars caudalis of T. f. pratincola, originates from the aponeurosis notarii (Fig 8A). This aponeurosis is located ventrally from the originating aponeurosis of the M. biventer cervicis. The aponeurosis notarii probably attaches to C14 (Fig 8I). A solid muscle belly originates from the aponeurosis notarii; this muscle belly runs cranially and inserts with a tendon (called tendo axialis) to the torus dorsalis (a lateral processus also known as epipophysis [25]) of C2 (Figs 8B and 9A). This muscle slip is approximately seven centimetres in length. From the processus spinosus of C13 (Fig 8H) a muscle slip originates tendinously and runs four centimetres cranially. This slip fuses with the tendo axialis which inserts on C2. Several other slips originate from the aponeurosis notarii and insert laterally on C6-C10 (Fig 8C–8G) and on more caudally located vertebrae with an interwoven network of inseparable muscle slips from which the insertion sites could not be identified precisely.


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. longus colli dorsalis, pars cranialis.A) Dorsal view on M. longus colli dorsalis, pars cranialis. Vertebrae numbers are indicated (C2-C7). The slips from the pars cranialis insert to the tendo axialis (ta) from a pars caudalis (ca) slip. The lateral processus of C2, which serve as insertion point for the tendo axialis are indicated with broken lines. The M. interspinalis (is), M. splenius capitis (sc) and M. longus colli dorsalis, pars profunda (pr) are indicated for reference. Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B-G) Muscle attachment sites of the M. longus colli dorsalis, pars cranialis indicated with red circles in the three-dimensional models of the vertebrae of T. f. pratincola from dorsal view (cranial is on top). Scale bars in B-G represent one millimetre (adapted from [5]). H) Connection diagram from lateral view of M. longus colli dorsalis, pars cranialis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips, broken lines represent the tendo axialis. The arrowhead indicates that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally. I) Connection diagram from dorsal view of M. rectus capitis ventralis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips. Broken lines indicate the tendo axialis. The arrowheads indicate that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0134272.g009: M. longus colli dorsalis, pars cranialis.A) Dorsal view on M. longus colli dorsalis, pars cranialis. Vertebrae numbers are indicated (C2-C7). The slips from the pars cranialis insert to the tendo axialis (ta) from a pars caudalis (ca) slip. The lateral processus of C2, which serve as insertion point for the tendo axialis are indicated with broken lines. The M. interspinalis (is), M. splenius capitis (sc) and M. longus colli dorsalis, pars profunda (pr) are indicated for reference. Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B-G) Muscle attachment sites of the M. longus colli dorsalis, pars cranialis indicated with red circles in the three-dimensional models of the vertebrae of T. f. pratincola from dorsal view (cranial is on top). Scale bars in B-G represent one millimetre (adapted from [5]). H) Connection diagram from lateral view of M. longus colli dorsalis, pars cranialis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips, broken lines represent the tendo axialis. The arrowhead indicates that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally. I) Connection diagram from dorsal view of M. rectus capitis ventralis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips. Broken lines indicate the tendo axialis. The arrowheads indicate that this muscle slip (from the M. longus colli dorsalis, pars caudalis) runs further caudally.
Mentions: Origin and insertion: The M. longus colli dorsalis, pars caudalis of T. f. pratincola, originates from the aponeurosis notarii (Fig 8A). This aponeurosis is located ventrally from the originating aponeurosis of the M. biventer cervicis. The aponeurosis notarii probably attaches to C14 (Fig 8I). A solid muscle belly originates from the aponeurosis notarii; this muscle belly runs cranially and inserts with a tendon (called tendo axialis) to the torus dorsalis (a lateral processus also known as epipophysis [25]) of C2 (Figs 8B and 9A). This muscle slip is approximately seven centimetres in length. From the processus spinosus of C13 (Fig 8H) a muscle slip originates tendinously and runs four centimetres cranially. This slip fuses with the tendo axialis which inserts on C2. Several other slips originate from the aponeurosis notarii and insert laterally on C6-C10 (Fig 8C–8G) and on more caudally located vertebrae with an interwoven network of inseparable muscle slips from which the insertion sites could not be identified precisely.

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.