The obliquus capitis inferior muscle () is the larger of the two oblique
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
s of the neck. It arises from the apex of the
spinous process of the
axis and passes laterally and slightly upward, to be inserted into the lower and back part of the
transverse process of the
atlas.
It lies deep to the
semispinalis capitis and
trapezius muscles.
The muscle is responsible for rotation of the head and first
cervical vertebra (
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 bo ...
).
It forms the lower boundary of the
suboccipital triangle 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. 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, occipital bone
The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobe ...
and obliquus capitis inferior muscle. The muscle arises from the apex of the spinous process of the axis and insert into the lower and back part of the transverse process of the atlas.
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