Pectoralis minor muscle

Last revised by Assoc Prof Craig Hacking on 15 Aug 2021

The pectoralis minor muscle is a muscle of the pectoral region lying deep to and completely covered by the pectoralis major muscle

It is an important anatomical landmark in two senses:

  1. it arbitrarily divides the axillary artery into 3 parts
  2. it arbitrarily divides the axillary lymph nodes into 3 levels

Summary

  • origin: anterior 3rd-5th ribs near the costal cartilages
  • insertion: medial and upper aspect of the coracoid process of the scapula
  • innervation: medial and lateral pectoral nerves
  • action
    • depresses shoulder
    • when scapula fixed, elevation of 3rd-5th ribs

Variant anatomy

  • pre-fixed origin: ribs 2-4
  • post-fixed origin: ribs 4-6
  • absence

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Cases and figures

  • Figure 1: pectoral muscles (Gray's illustrations)
    Drag here to reorder.
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