The internal intercostal muscles (intercostales interni) are a group of skeletal muscles located between the ribs. They are eleven in number on either side. They commence anteriorly at the sternum, in the intercostal spaces between the cartilages of the true ribs, and at the anterior extremities of the cartilages of the false ribs, and extend backward as far as the angles of the ribs, hence they are continued to the vertebral column by thin aponeuroses, the posterior intercostal membranes. They pull the sternum and ribs upward and inward.
Internal intercostal muscles
Internal intercostal muscles (red) seen from back.
Their fibers are also directed obliquely, but pass in a direction opposite to those of the external intercostal muscles. The internal intercostal muscles originate from the costal groove of the rib and insert into the superior aspect of the rib below in a direction perpendicular to the external intercostal muscles. It is this arrangement that allows these muscles to facilitate exhalation.[1]
For the most part, they are muscles of exhalation. In exhalation the interosseous portions of the internal intercostal muscles, (the part of the muscle that is between the bone portion of the superior and inferior ribs), depresses and retracts the ribs, compressing the thoracic cavity and expelling air.[2] The internal intercostals, however, are only used in forceful exhalation such as coughing or during exercise and not in relaxed breathing.[3] The external intercostal muscles, and the intercartilaginous part of the internal intercostal muscles, (the part of the muscle that lies between the cartilage portion of the superior and inferior ribs), are used in inspiration, by aiding in elevating the ribs and expanding the thoracic cavity.[4]
Additional images
Position of internal intercostal muscles (red). Animation.
The Obliquus internus abdominis.
Thoracic portion of the sympathetic trunk.
References
This article incorporates text in the public domain from page 403 of the 20th edition ofGray's Anatomy(1918)
^Tang A, Bordoni B. Anatomy, Thorax, Muscles. [Updated 2020 Jul 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538321/
^Basic Human Anatomy - O'Rahilly, Müller, Carpenter & Swenson[page needed]
^Anatomy and Physiology: The Unity of Form and Function 5th Edition by Kenneth Saladin[page needed]
^"The Action of the Internal Intercostals". www.yorku.ca.
External links
Wikimedia Commons has media related to Internal intercostal muscles.
Anatomy photo:18:03-0101 at the SUNY Downstate Medical Center - "The Internal Intercostal Muscle"
Anatomy figure: 18:03-03 at Human Anatomy Online, SUNY Downstate Medical Center - "Transverse section of thorax."
internal, intercostal, muscles, this, article, includes, list, general, references, lacks, sufficient, corresponding, inline, citations, please, help, improve, this, article, introducing, more, precise, citations, 2015, learn, when, remove, this, template, mes. This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations May 2015 Learn how and when to remove this template message The internal intercostal muscles intercostales interni are a group of skeletal muscles located between the ribs They are eleven in number on either side They commence anteriorly at the sternum in the intercostal spaces between the cartilages of the true ribs and at the anterior extremities of the cartilages of the false ribs and extend backward as far as the angles of the ribs hence they are continued to the vertebral column by thin aponeuroses the posterior intercostal membranes They pull the sternum and ribs upward and inward Internal intercostal musclesInternal intercostal muscles red seen from back DetailsOriginRib superior borderInsertionRib inferior borderArteryIntercostal arteriesNerveIntercostal nervesActionsHold ribs steadyAntagonistExternal intercostal musclesIdentifiersLatinMusculi intercostales interniTA98A04 4 01 013TA22312FMA74085Anatomical terms of muscle edit on Wikidata Contents 1 Structure 2 Additional images 3 References 4 External linksStructure EditTheir fibers are also directed obliquely but pass in a direction opposite to those of the external intercostal muscles The internal intercostal muscles originate from the costal groove of the rib and insert into the superior aspect of the rib below in a direction perpendicular to the external intercostal muscles It is this arrangement that allows these muscles to facilitate exhalation 1 For the most part they are muscles of exhalation In exhalation the interosseous portions of the internal intercostal muscles the part of the muscle that is between the bone portion of the superior and inferior ribs depresses and retracts the ribs compressing the thoracic cavity and expelling air 2 The internal intercostals however are only used in forceful exhalation such as coughing or during exercise and not in relaxed breathing 3 The external intercostal muscles and the intercartilaginous part of the internal intercostal muscles the part of the muscle that lies between the cartilage portion of the superior and inferior ribs are used in inspiration by aiding in elevating the ribs and expanding the thoracic cavity 4 Additional images Edit Position of internal intercostal muscles red Animation The Obliquus internus abdominis Thoracic portion of the sympathetic trunk References Edit This article incorporates text in the public domain from page 403 of the 20th edition of Gray s Anatomy 1918 Tang A Bordoni B Anatomy Thorax Muscles Updated 2020 Jul 27 In StatPearls Internet Treasure Island FL StatPearls Publishing 2020 Jan Available from https www ncbi nlm nih gov books NBK538321 Basic Human Anatomy O Rahilly Muller Carpenter amp Swenson page needed Anatomy and Physiology The Unity of Form and Function 5th Edition by Kenneth Saladin page needed The Action of the Internal Intercostals www yorku ca External links Edit Wikimedia Commons has media related to Internal intercostal muscles Anatomy photo 18 03 0101 at the SUNY Downstate Medical Center The Internal Intercostal Muscle Anatomy figure 18 03 03 at Human Anatomy Online SUNY Downstate Medical Center Transverse section of thorax Portal Anatomy Retrieved from https en wikipedia org w index php title Internal intercostal muscles amp oldid 1090856373, wikipedia, wiki, book, books, library,
