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 An aponeurosis (; plural: ''aponeuroses'') is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join musc ...

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 proces ...

, 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 ...

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 The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...

third Third or 3rd may refer to: Numbers * 3rd, the ordinal form of the cardinal number 3 * , a fraction of one third * Second#Sexagesimal divisions of calendar time and day, 1⁄60 of a ''second'', or 1⁄3600 of a ''minute'' Places * 3rd Street (d ...

, fourth, and fifth ribs past the

angle In Euclidean geometry, an angle is the figure formed by two Ray (geometry), rays, called the ''Side (plane geometry), sides'' of the angle, sharing a common endpoint, called the ''vertex (geometry), vertex'' of the angle. Angles formed by two ...

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.

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)

Structure

Function

Additional images

See also

References

External links