View source for Semispinalis muscles

{{Short description|Group of three muscles belonging to the transversospinales}}
{{Infobox muscle
| Name        = Semispinalis muscles
| Latin       = musculi semispinalis
| Image      = Semispinalis.png
| Caption    = Deep muscles of the back. Semispinalis muscles labelled and shown in red. Capitis uppermost, cervicis top centre left, thoracis centre right 
| Blood       =
| Nerve       = [[Greater occipital nerve]]
}}

The '''semispinalis muscles''' are a group of three [[muscle]]s belonging to the [[transversospinales]]. These are the semispinalis capitis, the semispinalis cervicis and the semispinalis thoracis.

==Location==
The '''semispinalis capitis''' (''complexus'') is situated at the upper and back part of the [[neck]], deep to the [[splenius muscles]], and medial to the [[longissimus cervicis]] and [[longissimus capitis]]. It arises by a series of tendons from the tips of the [[transverse processes]] of the upper six or seven [[Thoracic vertebrae|thoracic]] and the [[cervical vertebrae#Special cervical vertebrae|seventh]] [[cervical vertebrae]], and from the articular processes of the three cervical vertebrae above this ([[cervical vertebrae#General characteristics (C3-C6)|C4-C6]]).

The tendons, uniting, form a broad muscle, which passes upward, and is inserted between the superior and inferior [[nuchal lines]] of the [[occipital bone]]. It lies deep to the [[trapezius]] muscle and can be palpated as a firm round muscle mass just lateral to the cervical spinous processes.

The '''semispinalis cervicis''' (or ''semispinalis colli''), arises by a series of tendinous and fleshy fibers from the transverse processes of the upper five or six [[thoracic vertebrae]], and is inserted into the cervical [[spinous processes]], from the axis to the fifth [[cervical vertebrae]] inclusive. The semispinalis cervicis is thicker than the semispinalis thoracis. The fasciculus connected with the [[axis (anatomy)|axis]] is the largest, and is chiefly muscular in structure.

The '''semispinalis thoracis''' (or ''semispinalis dorsi'') muscle consists of thin, narrow, fleshy [[Muscle fascicle|fasciculi]], interposed between [[tendon]]s of considerable length. It arises by a series of small tendons from the [[transverse processes]] of the sixth to the tenth [[thoracic vertebrae]], and is inserted, by tendons, into the [[spinous processes]] of the upper four thoracic and lower two [[cervical vertebrae]].

The semispinalis muscles are innervated by the dorsal rami of the [[Cervical nerves|cervical spinal nerves]].

==See also==
* [[List of muscles of the human body]]

==Additional images==
<gallery>
 Image:Gray129.png|[[Occipital bone]]. Outer surface.
 Image:Gray187.png|[[Base of skull]]. Inferior surface.
 File:Slide1ccc.JPG|Semispinalis capitis muscle
 File:Gray384.png|Section showing cervicis and fascia
</gallery>

==References==
{{Gray's}}

==External links==
* {{SUNYAnatomyFigs|01|06|01}}
* {{SUNYAnatomyFigs|24|01|01}}
* {{DukeOrtho|Semispinalis_capitis_1}}
* {{NormanAnatomy|lesson6musclesofback}}
* {{SUNYAnatomyFigs|01|06|01}}
* [http://www.ithaca.edu/faculty/lahr/LE2000/Back/FinishedPics/JPEGs/SemiThorClose.jpg Image at ithaca.edu]
* {{DukeOrtho|Semispinalis_thoracis}}
* {{ViennaCrossSection|pembody/body8a}}

{{Muscles of thorax and back}}
{{Portal bar|Anatomy}}
{{Authority control}}

[[Category:Muscles of the torso]]