Intercostal muscle

You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.

Intercostal muscle
Deep muscles of the chest and front of the arm, with the boundaries of the axilla.
Gray's	subject #117 403
Origin	ribs 1-11
Insertion	ribs 2-12
Artery:	intercostal arteries
Nerve:	intercostal nerves
Action:
MeSH	Intercostal+Muscles

Intercostal muscles are several groups of muscles that run between the ribs, and help form and move the chest wall.

There are three principal layers;

• the external intercostal muscles, which aid in quiet and forced inhalation. They originate on ribs 1-11 and have their insertion on ribs 2-12. The external intercostals are responsible for the elevation of the ribs, and expanding the transverse dimensions of the thoracic cavity.

Located around the the ribs

• the internal intercostal muscles, which aid in forced expiration (quiet expiration is a passive process). They originate on ribs 1-11 and have their insertions on ribs 2-12. The internal intercostals are responsible for the depression of the ribs decreasing the transverse dimensions of the thoracic cavity.
• the innermost intercostal muscle

Both the external and internal muscles are innervated by the intercostal nerves (the ventral rami of thoracic spinal nerves), and are provided by the intercostal arteries and intercostal veins. Their fibers run in opposite directions.

Other intercostal muscles

Besides the scaleni, which also move the chest wall and have a function in inhalation, other intercostal muscles are:

• Subcostal muscles
• Transversus thoracis muscle

External links

• -294977459 at GPnotebook
• SUNY Figs 18:03-03
• UCC

v • d • e List of muscles of torso
BACK	splenius (capitis, cervicis) - erector spinae (iliocostalis, longissimus, spinalis) - latissimus dorsi transversospinales: (semispinalis dorsi, semispinalis cervicis, semispinalis capitis, multifidus, rotatores) - interspinales - intertransversarii
SUBOCCIPITAL	rectus capitis posterior (major, minor) - obliquus capitis (inferior, superior)
CHEST	intercostales (external, internal, innermost) - subcostales - transversus thoracis - levatores costarum - serratus posterior (inferior, superior) - diaphragm
ABDOMEN	anterior/lateral wall: obliques (external, internal) - transversus abdominis - rectus abdominis - pyramidalis posterior wall: quadratus lumborum - psoas major/psoas minor - iliacus cremaster
PELVIS/FLOOR	levator ani (iliococcygeus, pubococcygeus, puborectalis) - coccygeus
PERINEUM	anal triangle: sphincter ani (externus, internus) superficial perineal pouch (superficial transverse perineal, bulbospongiosus, ischiocavernosus) deep perineal pouch (deep transverse perineal, sphincter urethrae membranaceae)

Acknowledgement and Attribution Regarding Sources of Content

Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .