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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.


Related in: MedlinePlus

M. biventer cervicis.A) Dorsal view on both M. biventer cervicis sinister and dexter. The two sides are placed apart by needles, but in situ located dorsally from the M. longus colli dorsalis (lcd). M. biventer cervicis originates from the dorsocaudally located aponeurosis notarii (an), which is partly covered by thoracic muscles (tm). The cranial (cr) and caudal (ca) bellies are connected by the intersectio tendinea (it). M. biventer cervicis inserts at the cranium, ventral from the insertion of the M. complexus (c). Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B) Insertion site of the M. biventer cervicis on the skull (red line) as seen from dorsal (D) view. Foramen magnum (FM) and condylus occipitalis (CO) are indicated in the skull. Scale bar represents one millimetre (adapted from [5]). C) Connection diagram from lateral view of M. biventer cervicis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips; broken line represents intersectio tendinea. The heavy line above C14 represents aponeurosis notarii. D) Connection diagram from dorsal view of M. biventer cervicis, in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle and broken lines indicating intersectio tendinea. The heavy line above C14 represent the aponeurosis notarii.
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pone.0134272.g002: M. biventer cervicis.A) Dorsal view on both M. biventer cervicis sinister and dexter. The two sides are placed apart by needles, but in situ located dorsally from the M. longus colli dorsalis (lcd). M. biventer cervicis originates from the dorsocaudally located aponeurosis notarii (an), which is partly covered by thoracic muscles (tm). The cranial (cr) and caudal (ca) bellies are connected by the intersectio tendinea (it). M. biventer cervicis inserts at the cranium, ventral from the insertion of the M. complexus (c). Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B) Insertion site of the M. biventer cervicis on the skull (red line) as seen from dorsal (D) view. Foramen magnum (FM) and condylus occipitalis (CO) are indicated in the skull. Scale bar represents one millimetre (adapted from [5]). C) Connection diagram from lateral view of M. biventer cervicis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips; broken line represents intersectio tendinea. The heavy line above C14 represents aponeurosis notarii. D) Connection diagram from dorsal view of M. biventer cervicis, in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle and broken lines indicating intersectio tendinea. The heavy line above C14 represent the aponeurosis notarii.

Mentions: Muscle characteristics: The M. biventer cervicis is relatively long and thin (Fig 2A). It is the only muscle that connects the cranium with the notarium (a unit of fused thoracic vertebrae) [6]. In T. f. pratincola it originates from the aponeurosis notarii (which is located dorsally from C14 and then runs caudally) and inserts at the os supraoccipitale (Fig 2A), spanning a length of more than eight centimetres (Fig 2A). The aponeurosis which gives rise to the M. biventer cervicis even runs more caudally, dorsally from the thoracic vertebrae. The M. biventer cervicis in T. f. pratincola has two parallel fibred fleshy bellies interconnected by a tendon (intersectio tendinea). The transition from the muscle belly to the intersectio tendinea is gradually, and is located at the position of C4 for the cranial belly and at C8/C9 for the caudal belly. The cranial belly and the tendinous part have about the same length, but the caudal belly is clearly longer than the cranial belly. The sides of the cranial bellies of the M. biventer cervicis sinister and dexter touch each other dorsomedially. Most of the M. biventer cervicis is located dorsally to all other cervical muscles; only its origin and insertion are covered by other muscles. The connection schemes are simple, showing the extent of the muscles over the whole cervical column (Fig 2C and 2D).


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. biventer cervicis.A) Dorsal view on both M. biventer cervicis sinister and dexter. The two sides are placed apart by needles, but in situ located dorsally from the M. longus colli dorsalis (lcd). M. biventer cervicis originates from the dorsocaudally located aponeurosis notarii (an), which is partly covered by thoracic muscles (tm). The cranial (cr) and caudal (ca) bellies are connected by the intersectio tendinea (it). M. biventer cervicis inserts at the cranium, ventral from the insertion of the M. complexus (c). Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B) Insertion site of the M. biventer cervicis on the skull (red line) as seen from dorsal (D) view. Foramen magnum (FM) and condylus occipitalis (CO) are indicated in the skull. Scale bar represents one millimetre (adapted from [5]). C) Connection diagram from lateral view of M. biventer cervicis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips; broken line represents intersectio tendinea. The heavy line above C14 represents aponeurosis notarii. D) Connection diagram from dorsal view of M. biventer cervicis, in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle and broken lines indicating intersectio tendinea. The heavy line above C14 represent the aponeurosis notarii.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0134272.g002: M. biventer cervicis.A) Dorsal view on both M. biventer cervicis sinister and dexter. The two sides are placed apart by needles, but in situ located dorsally from the M. longus colli dorsalis (lcd). M. biventer cervicis originates from the dorsocaudally located aponeurosis notarii (an), which is partly covered by thoracic muscles (tm). The cranial (cr) and caudal (ca) bellies are connected by the intersectio tendinea (it). M. biventer cervicis inserts at the cranium, ventral from the insertion of the M. complexus (c). Coordinate system indicates lateral (L), caudal (Ca) and cranial (Cr). Scale bar represents one centimetre. B) Insertion site of the M. biventer cervicis on the skull (red line) as seen from dorsal (D) view. Foramen magnum (FM) and condylus occipitalis (CO) are indicated in the skull. Scale bar represents one millimetre (adapted from [5]). C) Connection diagram from lateral view of M. biventer cervicis in T. f. pratincola; origin and insertion sites are connected with lines representing the muscle slips; broken line represents intersectio tendinea. The heavy line above C14 represents aponeurosis notarii. D) Connection diagram from dorsal view of M. biventer cervicis, in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle and broken lines indicating intersectio tendinea. The heavy line above C14 represent the aponeurosis notarii.
Mentions: Muscle characteristics: The M. biventer cervicis is relatively long and thin (Fig 2A). It is the only muscle that connects the cranium with the notarium (a unit of fused thoracic vertebrae) [6]. In T. f. pratincola it originates from the aponeurosis notarii (which is located dorsally from C14 and then runs caudally) and inserts at the os supraoccipitale (Fig 2A), spanning a length of more than eight centimetres (Fig 2A). The aponeurosis which gives rise to the M. biventer cervicis even runs more caudally, dorsally from the thoracic vertebrae. The M. biventer cervicis in T. f. pratincola has two parallel fibred fleshy bellies interconnected by a tendon (intersectio tendinea). The transition from the muscle belly to the intersectio tendinea is gradually, and is located at the position of C4 for the cranial belly and at C8/C9 for the caudal belly. The cranial belly and the tendinous part have about the same length, but the caudal belly is clearly longer than the cranial belly. The sides of the cranial bellies of the M. biventer cervicis sinister and dexter touch each other dorsomedially. Most of the M. biventer cervicis is located dorsally to all other cervical muscles; only its origin and insertion are covered by other muscles. The connection schemes are simple, showing the extent of the muscles over the whole cervical column (Fig 2C and 2D).

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.


Related in: MedlinePlus