Iliocostalis muscle is the muscle immediately lateral to the
longissimus that is the nearest to the furrow that separates the
epaxial muscles from the
hypaxial. It lies very deep to the fleshy portion of the
serratus posterior muscle. It laterally
flexes the
vertebral column
The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmente ...
to the same side.
Structure
Iliocostalis muscle has a common origin from the
iliac crest, the
sacrum, the
thoracolumbar fascia, and the
spinous processes of the
vertebrae from
T11 to
L5.
Iliocostalis cervicis (cervicalis ascendens) arises from the angles of the third, fourth, fifth, and sixth ribs, and is inserted into the
posterior tubercles of the transverse processes of the fourth, fifth, and sixth cervical vertebrae.
Iliocostalis thoracis (musculus accessorius; iliocostalis thoracis) arises by flattened tendons from the upper borders of the angles of the lower six ribs medial to the tendons of insertion of the iliocostalis lumborum; these become muscular, and are inserted into the upper borders of the angles of the upper six ribs and into the back of the
transverse process of the seventh
cervical vertebra.
Iliocostalis lumborum (iliocostalis muscle; sacrolumbalis muscle) is inserted, by flattened
tendon
A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
s, into the inferior borders of the angles of the lower six to nine
ribs.
Nerve supply
Iliocostalis muscle is supplied by the
dorsal rami of
spinal nerves.
Function
Iliocostalis muscle laterally
flexes the
vertebral column
The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmente ...
to the same side.
It bilaterally extends the vertebral column.
See also
*
Erector spinae muscles
*
Longissimus muscles
*
Semispinalis muscles
*
Spinalis muscle
References
External links
* – "Intrinsic muscles of the back."
Dissection at ithaca.edu
Muscles of the torso
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