Internal intercostal muscles

The Internal Intercostal Muscles (shown in red)

The Internal Intercostal Muscles are a group of skeletal muscles located between the ribs. They are primarily involved in the mechanical aspect of breathing, specifically in the process of exhalation.

Anatomy

The Internal Intercostal Muscles are found between the ribs of the human body. They extend from the tubercles of the ribs behind, to the cartilages of the ribs in front, with the exception of the first pair, which extend from the neck of the first rib to the cartilage of the second rib.

Function

The primary function of the Internal Intercostal Muscles is to aid in the process of exhalation. They depress the ribs and decrease the transverse dimensions of the thoracic cavity, which increases the pressure within the thorax, forcing air out of the lungs.

Clinical Significance

Dysfunction or injury to the Internal Intercostal Muscles can lead to breathing difficulties and pain. Conditions such as Intercostal Neuralgia and Costochondritis can affect these muscles.

See Also

• External Intercostal Muscles
• Intercostal Nerves
• Respiratory System