The obliquus capitis superior muscle () is a small

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

in the upper back part of the

neck The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...

. It is one of the

suboccipital muscles The suboccipital muscles are a group of muscles defined by their location to the occiput. Suboccipital muscles are located below the occipital bone The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput ( ...

. It attaches inferiorly at the transverse process of the atlas (first cervical vertebra); it attaches superiorly at the external surface of the

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 lies over the occipital lob ...

. The muscle is innervated by the suboccipital nerve (the posterior ramus of the first cervical

spinal nerve A spinal nerve is a mixed nerve, which carries Motor neuron, motor, Sensory neuron, sensory, and Autonomic nervous system, autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each s ...

). It acts at the atlanto-occipital joint to extend the head and bend the head to the same side.

Anatomy

The obliquus capitis superior muscle is one of the

. It forms the superolateral boundary of the suboccipital triangle. It extends superoposteriorly from its inferior attachment to its superior attachment, becoming wider superiorly.

Attachments

The muscle's inferior attachment is at the superior surface of the

transverse process Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

of the atlas (C1). Its superior attachment is onto the lateral portion of the external surface of the occipital bone between the

superior nuchal line The nuchal lines are four curved lines on the external surface of the occipital bone: * The upper, often faintly marked, is named the highest nuchal line, but is sometimes referred to as the Mempin line or linea suprema, and it attaches to the e ...

and inferior nuchal line. Its superior attachment is situated lateral to that of the semispinalis capitis muscle, and overlaps the attachment of the

rectus capitis posterior major muscle The rectus capitis posterior major (or rectus capitis posticus major) is a muscle in the upper back part of the neck. It is one of the suboccipital muscles. Its inferior attachment is at the spinous process of the axis (Second cervical vertebra); ...

Innervation

The muscle receives motor innervation from the suboccipital nerve (i.e. the posterior ramus of the cervical spinal nerve 1 (C1)).

Actions/movements

The muscle extends and (ipsilaterally) laterally flexes the head.

Additional images

File:Obliquus capitis superior muscle - animation04.gif, Position of obliquus capitis superior (shown in red). Animation. File:Obliquus capitis superior muscle05.png, Still image. Posterior view. File:Obliquus capitis superior.png, Deep muscles of the back (obliquus capitis superior labeled at upper left) File:Gray129.png,

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 lies over the occipital lob ...

. Outer surface. Muscle attachments are shown as red circles. File:Gray187.png,

Base of skull The base of skull, also known as the cranial base or the cranial floor, is the most Anatomical terms of location#Superior and inferior, inferior area of the human skull, skull. It is composed of the endocranium and the lower parts of the Calvaria ...

. Inferior surface. Muscle attachments are shown as red circles.

References

External links

* {{Authority control Muscles of the head and neck