Chest Muscles

While the pectoralis major and minor are often the most recognized muscles in the chest area, they represent only a part of the complex muscular structure in this region. The chest comprises several other vital components, including the intercostal muscles and associated structures essential for the movement and support of the ribcage, shoulders, and arms.

Names of All the Muscles in the Chest With Location & Anatomy

The muscles in this group are all attached to the axial skeleton (skull, ribcage, vertebral column, and sternum), as they all originate from the ribs, vertebrae, or sternum.

Muscles in the Thoracic Region

Some chest muscles, like the intercostals, are considered axial muscles, as their origin and insertion both lie in the axial skeleton. These muscles, which lie deep in the thoracic region, form the walls of the thoracic cavity and mostly help with respiration.

Here is a list of all the muscles in the thoracic region:

Name	Location	Attachments	Function
Thoracic (Chest) Wall Muscles
Intercostals	Intercostal spaces between ribs	Origin: Ribs Insertion: Ribs	Elevating and depressing the ribs to control thoracic volume during breathing
— External	Between the ribs, from the spines in the back to the sternum at the front, slanting downward and forward from the rib above to the rib below.	Origin: Lower borders of 1st to 11th ribs Insertion: Upper borders of 2nd-12th ribs	Elevating the ribcage to increase its volume during forced inhalation
— Internal	Occupy the same space between the ribs but lie beneath the external intercostals. They run in the opposite direction, slanting downward and backward.	Origin: Costal groove of 1st to 11th ribs Insertion: Upper borders of 2nd-12th ribs	Depressing the rib cage to reduce its volume during forced exhalation
— Innermost	Deep to the internal intercostals, occupying the same spaces and having the same orientation of the muscle fibers.	Origin: Interior surface and borders of the 1st-11th ribs Insertion: Upper borders of 2nd-12th ribs	Maintaining the integrity of the ribcage during respiration and helping the internal intercostals
Subcostalis	One of the deepest muscles in thoracic region, most prominent along the inner surface of the lower ribs, often spanning multiple intercostal spaces.	Origin: Angle of the ribs, especially the lower ribs Insertion: Inner surface and upper borders of the ribs below their origin	Depressing the rib cage during forced exhalation
Transversus thoracis	On the inside of the front of the rib cage, right behind the sternum and the costal cartilages.	Origin: Posterior surface of the xiphoid process and body of sternum, and costal cartilages of 4th-7th ribs. Insertion: Costal cartilage of 2nd-6th ribs	Depressing the ribs (mainly 2nd-6th) during forced exhalation
Levatores costarum	Along the back, running from the spine to ribs at the back of the ribcage.	Origin: Transverse processes of C7-T11 vertebrae Insertion: Upper surface of the rib immediately below the origin of each strip	Elevating the ribcage during inhalation
Serratus posterior	Group of muscles connecting the vertebrae to the ribs.	Origin: Spinous processes of vertebrae Insertion: Ribs	Helping with respiration
— Serratus posterior inferior	Lower back region, below the shoulder blades, and above the hips.	Origin: Spinous processes of T11-L2 vertebrae Insertion: Lower borders of 9th-12th ribs	Depressing the lower ribs during exhalation
— Serratus posterior superior	Upper back region, just beneath the neck, and between the shoulder blades.	Origin: Nuchal ligament and spinous processes of the C7-T3 vertebrae Insertion: Upper borders of 2nd-5th ribs	Elevating the upper ribs during inhalation
Other Muscles in the Thoracic Cavity
Diaphragm	Dome-shaped sheet muscle between the thoracic and abdominal cavities, separating the two.	Origin: In three parts, from the back of the xiphoid process, inner surface of 7th-12th ribs, and 1st-3rd lumbar vertebrae Insertion: Central tendon of the diaphragm	A primary muscle of respiration, helping in increasing and decreasing the thoracic volume to draw air in and then expel it for breathing to happen

Muscles in the Pectoral Region

Muscles like the pectoralis major and minor attach to both the axial and appendicular skeletons, making them axioappendicular muscles. Their actions often involve helping shoulder and arm movements. These lie superficially in the chest and are grouped into the muscles of the pectoral region.

Name	Location	Attachments	Function
Pectoralis major	The biggest chest muscle, extending from the shoulder region across the front of the chest,  covering the ribs.	Origin: In two heads, from the clavicle and the costal cartilages of the 1st-6th ribs. Insertion: Bicipital groove and greater tubercle of the humerus	Flexing the arms forward, rotating them at the shoulder, and adducting them in front, across the chest
Pectoralis minor	In the upper chest, near the shoulder, under the pectoralis major	Origin: Sternal end of 3rd-5th ribs Insertion: Coracoid process of scapula	Stabilizing the scapula, and elevating the 3rd-5th ribs during inhalation
Subclavius	At the front of the chest, underneath the collarbones	Origin: Sternal end of 1st rib Insertion: Subclavian groove of the clavicle or collarbone	Depressing the clavicle and keeping it steady during shoulder movements
Serratus anterior	On the sides of the chest, under the armpits, and along the ribs.	Origin: in three parts, from 1st-8th ribs Insertion: In three parts, into the scapula’s angles and borders	Abducting the scapula and rotating it when raising the arms