The serratus posterior superior muscle is a thin, quadrilateral muscle. It is situated at the upper back part of the
thorax
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...
, deep to the
rhomboid muscles
The rhomboid muscles (), often simply called the rhomboids, are rhombus-shaped muscles associated with the scapula. There are two rhomboid muscles on each side of the upper back:
* Rhomboid major muscle
* Rhomboid minor muscle
The large rhom ...
.
Structure
The serratus posterior superior muscle arises by an
aponeurosis from the lower part of the
nuchal ligament
The nuchal ligament is a ligament at the back of the neck that is continuous with the supraspinous ligament.
Structure
The nuchal ligament extends from the external occipital protuberance on the skull and median nuchal line to the spinous proc ...
, from the
spinous processes
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 i ...
of
C7,
T1,
T2, and sometimes
T3, and from the
supraspinal ligament
The supraspinous ligament, also known as the supraspinal ligament, is a ligament found along the vertebral column.
Structure
The supraspinous ligament connects the tips of the spinous processes from the seventh cervical vertebra to the sacrum. Abo ...
.
It is inserted, by four fleshy digitations into the upper borders of the
second,
third,
fourth, and fifth
ribs past the
angle
In Euclidean geometry, an angle is the figure formed by two rays, called the '' sides'' of the angle, sharing a common endpoint, called the '' vertex'' of the angle.
Angles formed by two rays lie in the plane that contains the rays. Angles a ...
of the rib.
Function
The serratus posterior superior muscle elevates the second to fifth ribs. This aids deep respiration.
Additional images
File:Serratus posterior superior muscle animation small.gif, Position of serratus posterior superior muscle (shown in red).
File:Serratus posterior superior.jpg, Serratus posterior superior muscles are labeled at center left and center right.
See also
*
Serratus anterior muscle
The serratus anterior is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula. The serratus anterior acts to pull the scapula fo ...
*
Serratus posterior inferior muscle
The serratus posterior inferior muscle, also known as the posterior serratus muscle, is a muscle of the human body.
Structure
The muscle is situated at the junction of the thoracic and lumbar regions. It has an irregularly quadrilateral form, ...
References
*Clinically Oriented Anatomy, 4th ed. Keith L. Moore and Arthur F. Dalley.
*Board Review Series: Gross Anatomy, 4th ed. Kyung Won Chung.
External links
* - "Intermediate layer of the extrinsic muscles of the back, deep muscles."
{{Authority control
Muscles of the torso
Thorax (human anatomy)