Los músculos intercostales internos forman parte de la pared torácica. Se encuentran por debajo de los músculos intercostales externos. Sus fibras están orientadas en dirección inferior y posterior. Inserciones: se originan en el borde lateral del surco costal y se insertan en la superficie superior de la costilla inferior. Acciones: estabilizan la posición de las costillas durante la respiración normal. Empuja las costillas hacia abajo y reduce el volumen torácico durante la espiración forzada. Inervación: nervios intercostales (T1-T11). Irrigación sanguínea: arterias intercostales anteriores y posteriores. By TeachMeSeries Ltd (2026) Fig. 1: los músculos intercostales externos e internos de la pared torácica. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Atlas Prosection of the muscles of the thoracic wall. Prosection of the muscles of the thoracic wall. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Frequent questions What are the intercostales internos and where are they located? The intercostales internos are muscles that form part of the thoracic wall, situated beneath the external intercostal muscles. Their fibres run in an inferior and posterior direction. What are the primary functions of the intercostales internos muscles? These muscles stabilise the position of the ribs during normal respiration and assist in pushing the ribs downwards, which reduces thoracic volume during forced expiration. What is the origin and insertion of the intercostales internos? The intercostales internos originate from the lateral border of the costal groove and insert into the superior surface of the rib below. This positioning facilitates their role in rib movement. How are the intercostales internos innervated? The intercostales internos are innervated by the intercostal nerves, specifically from T1 to T11. This innervation is crucial for their motor function during respiration. What is the blood supply to the intercostales internos muscles? The intercostales internos receive blood supply from the anterior and posterior intercostal arteries. This vascularisation supports their metabolic needs during respiratory activities. Rate This Article