The obliquus capitis inferior muscle () is the larger of the two oblique
muscles of the neck. It arises from the apex of the
spinous process
The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
of the
axis
An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to:
Mathematics
* Axis of rotation: see rotation around a fixed axis
* Axis (mathematics), a designator for a Cartesian-coordinat ...
and passes laterally and slightly upward, to be inserted into the lower and back part of the
transverse process
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
of the
atlas
An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth.
Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...
.
It lies deep to the
semispinalis capitis
The semispinalis muscles are a group of three muscles belonging to the transversospinales. These are the semispinalis capitis, the semispinalis cervicis and the semispinalis thoracis.
The semispinalis capitis (''complexus'') is situated at the ...
and
trapezius
The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports th ...
muscles.
The muscle is responsible for rotation of the head and first
cervical vertebra
In tetrapods, cervical vertebrae (singular: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In sa ...
(
atlanto-axial joint
The atlanto-axial joint is a joint in the upper part of the neck between the atlas bone and the axis bone, which are the first and second cervical vertebrae. It is a pivot joint.
Structure
The atlanto-axial joint is a joint between the atlas ...
).
It forms the lower boundary of the
suboccipital triangle
The suboccipital triangle is a region of the neck bounded by the following three muscles of the suboccipital group of muscles:
* Rectus capitis posterior major - above and medially
* Obliquus capitis superior - above and laterally
* Obliquus cap ...
of the neck.
The naming of this muscle may be confusing, as it is the only capitis (L. "head") muscle that does NOT attach to the cranium.
Function
The obliquus capitis inferior muscle, like the other suboccipital muscles, has an important role in
proprioception
Proprioception ( ), also referred to as kinaesthesia (or kinesthesia), is the sense of self-movement, force, and body position. It is sometimes described as the "sixth sense".
Proprioception is mediated by proprioceptors, mechanosensory neurons ...
. This muscle has a very high density of Golgi organs and muscle spindles which accounts for this.
It is believed that proprioception may be the primary role of the inferior oblique (and indeed the other suboccipital muscles) allowing accurate positioning of the head on the neck.
Additional Images
File:Obliquus capitis inferior muscle animation small.gif, Position of obliquus capitis inferior muscle (shown in red).
File:Obliquus capitis inferior muscle closeup animation small.gif, Close up. Vertebral column
The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordate ...
, occipital bone and obliquus capitis inferior muscle. The muscle arises from the apex of the spinous process
The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
of the axis
An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to:
Mathematics
* Axis of rotation: see rotation around a fixed axis
* Axis (mathematics), a designator for a Cartesian-coordinat ...
and insert into the lower and back part of the transverse process
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
of the atlas
An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth.
Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...
.
File:Suboccipital triangle dissection.jpg, Obliquus capitis inferior's relationship to other suboccipital muscles.
References
External links
Muscles of the head and neck
{{muscle-stub