External intercostal muscles

External Intercostal Muscles

The External Intercostal Muscles, as seen from the front of the ribcage. Image courtesy of Wikimedia Commons.

The External Intercostal Muscles are a group of muscles found between the ribs in the human body. They are responsible for the mechanical aspect of breathing, aiding in both inhalation and forced exhalation.

Anatomy

The External Intercostal Muscles are eleven in number on each side. They extend from the tubercles of the ribs behind, to the cartilages of the ribs in front, and are continuous with the Internal Intercostal Muscles. They are thicker and broader at the back than at the front of the chest.

Function

The primary function of the External Intercostal Muscles is to assist in respiration. During inhalation, these muscles contract, elevating the ribs and expanding the chest cavity. This allows for the lungs to expand and fill with air. During forced exhalation, the External Intercostal Muscles relax, allowing the ribs and chest cavity to contract and expel air from the lungs.

Clinical Significance

Damage or injury to the External Intercostal Muscles can result in difficulty breathing and pain during respiration. Conditions such as Intercostal Neuralgia and Costochondritis can affect these muscles.

See Also

• Internal Intercostal Muscles
• Intercostal Nerves
• Respiratory System