Rectus capitis posterior major muscle

{{Infobox muscle

| Name = Rectus capitis posterior major muscle

| Latin = musculus rectus capitis posterior major

| Image = Rectus capitis posterior major muscle.PNG

| Caption = Deep muscles of the back. (Rect. post. major visible at upper left.)

| Origin = Spinous process of the axis (C2)

| Insertion = Inferior nuchal line of the occipital bone

| Action = Ipsilateral rotation of head and extension

| Blood = Occipital artery

| Nerve = Dorsal ramus of C1 (suboccipital nerve), sub-occipital nerve

}}

The rectus capitis posterior major (or rectus capitis posticus major{{Citation needed|date=August 2023}}) 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); its superior attachment is onto the outer surface of the occipital bone on and around the side part of the inferior nuchal line. The muscle is innervated by the suboccipital nerve (the posterior ramus of cervical spinal nerve C1). The muscle acts to extend the head and rotate the head to its side.

Anatomy

The rectus capitis posterior major muscle is one of the suboccipital muscles. It forms the superomedial boundary of the suboccipital triangle.{{Cite book |last=Standring |first=Susan |url=https://www.worldcat.org/oclc/1201341621 |title=Gray's Anatomy: The Anatomical Basis of Clinical Practice |year=2020 |isbn=978-0-7020-7707-4 |edition=42th |location=New York |pages=848–849 |oclc=1201341621}}

The muscle extends obliquely{{Cite book |last=Sinnatamby |first=Chummy S. |title=Last's Anatomy |vauthors= |publisher= |year=2011 |isbn=978-0-7295-3752-0 |edition=12th |pages=430}} superiolaterally from its inferior attachment to its superior attachment. It becomes broader superiorly.

= Attachments =

Its inferior attachment is (via a pointed tendon) at (the external aspect of) the (bifid) spinous process of the axis (cervical vertebra C2).

Its superior attachment is at (the lateral portion of) the inferior nuchal line and the surface of the occipital bone just inferior to this line.

= Innervation =

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

= Relations =

Superiorly, as the two muscles diverge laterally, they create between them a triangular space in which parts of the two recti capitis posteriores minores muscles are exposed.

= Actions/movements =

The muscle extends the head and (acting together with the obliquus capitis inferior muscle) ipsilaterally rotates the head.

Function

Its main actions are to extend and rotate the atlanto-occipital joint.

Research

A soft tissue connection bridging from the rectus capitis posterior major to the cervical dura mater was described in 2011. Various clinical manifestations may be linked to this anatomical relationship.{{cite journal |author1=Frank Scali |author2=Eric S. Marsili |author3=Matt E. Pontell |title=Anatomical Connection Between the Rectus Capitis Posterior Major and the Dura Mater|journal=Spine|pmid=21278628 |year=2011 |volume=36 |issue=25 |pages=E1612–4 |doi=10.1097/BRS.0b013e31821129df|s2cid=31560001 }} It has also been postulated that this connection serves as a monitor of dural tension along with the rectus capitis posterior minor and the obliquus capitis inferior.{{Citation needed|date=August 2023}}

Additional images

File:Rectus_capitis_posterior_major_muscle_animation_small.gif|Position of rectus capitis posterior major muscle (shown in red).

File:Rectus capitis posterior major.png|Rectus capitis posterior major muscle.

File:Gray129.png|Occipital bone. Outer surface.

File:Suboccipital triangle dissection.jpg|Rectus capitis posterior major's relationship to other suboccipital muscles.

References

External links

[https://web.archive.org/web/20050804024427/http://www.ptcentral.com/muscles/musclehead.html#rectus%20capitis%20posterior%20major PTCentral]
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Category:Muscles of the head and neck