Pectoralis minor muscle
Pectoralis minor (shown in red).
Pectoralis minor muscle (shown in red). The bone shown in blue is shoulder blade.
|Latin||Musculus pectoralis minor|
|Origin||Third to fifth ribs, near their costal cartilages|
|Insertion||Medial border and superior surface of the coracoid process of the scapula|
|Artery||Pectoral branch of the thoracoacromial trunk|
|Nerve||Medial pectoral nerve (C8, T1)|
|Actions||Stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall|
|Anatomical terms of muscle|
Origin and insertion
Axillary nodes are classified according to their positions relative to the pectoralis minor muscle. Level 1 are lateral, Level 2 are deep, Level 3 are medial. Pectoralis Minor divides the axillary artery into three parts.
The pectoralis minor muscle is covered anteriorly (superficially) by the clavipectoral fascia. The medial pectoral nerve pierces the pectoralis minor and the clavipectoral fascia. In attaching to the coracoid process, the pectoralis minor forms a 'bridge' - structures passing into the upper limb from the thorax will pass directly underneath.
The origin is from the second, third and fourth or fifth ribs. The tendon of insertion may extend over the coracoid process to the greater tubercle. It may be split into several parts. Absence of this muscle is rare but happens with certain uncommon diseases.
|Wikimedia Commons has media related to Pectoralis minor muscles.|
- Origin, insertion and nerve supply of the muscle at Loyola University Chicago Stritch School of Medicine
- UWASH pectoralisminor
- 13631566 at GPnotebook
- SUNY Figs 04:04-05
- SUNY Figs 05:02-08
- Anatomy photo:05:ov-0200 at the SUNY Downstate Medical Center
- Anatomy photo:05:01-0102 at the SUNY Downstate Medical Center
- Muscles/PectoralisMinor at exrx.net