German Contact Help Login Register

The Pectoralis Major Muscle

 

Anatomy and supply

The pectoralis major muscle (green highlighted on the picture) is a strong, fan-shaped muscle of the shoulder joint. It decisively shapes the surface anatomy of the breast. Furthermore it participates in forming the anterior wall of the axilla. The innervation is carried by the medial and lateral pectoral nerves (C5-Th1), direct branches of the brachial plexus. Due to its various origins the muscle is subdivided in three parts:

All fibers insert together at the crest of the greater tubercle located at the proximal humeral shaft. Due to the different courses of the muscle fibers the insertion has a recess which is open to the top preventing the muscle from overstretching. The triangular depression between the pectoralis major muscle, deltoid muscle and clavicle is called infraclavicular fossa (Mohrenheim’s fossa). Here the cephalic vein passes through in the subfascia within the deltopectoral groove.

Function

The pectoralis major muscle is the most important muscle for the adduction and anteversion of the shoulder joint which is why it is also known as the “breaststroke muscle”. It rotates the upper arm outwards and makes a powerful stroke movement (retroversion) when the arms are elevated (e.g. in wood-chopping). If the arms are fixed the muscle lifts the trunk which can be helpful in climbing or during inspiration (inspiratory breathing muscle).

Pathology

Aplasias of the pectoralis major muscle rank among the most common muscular malformations. In Poland syndrome the development of the breast wall remains incomplete during embryogenesis. It is distinguished by a defect of the pectoralis major muscle along with further faulty developments of the upper extremities (e.g. finger malformation). Hereby the chest muscle may be partially or completely missing. Depending on the degree of severity both the adduction and anteversion of the shoulder joint may be hindered (e.g. crossing the elevated arms). Moreover the affected people show visibly disfigured breasts so that plastic surgical reconstruction might be a therapeutic option.

Get me the rest of this article for free
Create your account and you’ll be able to see the rest of this article, plus videos and a quiz to help you memorize the information, all for free. You’ll also get access to articles, videos, and quizzes about dozens of other anatomy systems.
Create your free account ➞
Show references

References:

  • D. Drenckhahn/J. Waschke: Taschenbuch Anatomie, 1.Auflage, Urban & Fischer Verlag/Elsevier (2008), S.31-32
  • M. Schünke/E. Schulte/U. Schumacher: Prometheus – LernAtlas der Anatomie – Allgemeine Anatomie und Bewegungssystem, 2.Auflage, Thieme Verlag (2007), S.302-303, 374-376
  • W. Graumann/ D.Sasse: CompactLehrbuch der gesamten Anatomie – Band 2 – Bewegungsapparat, Schattauer Verlag (2003), S.271-273
  • F. Gohlke/A. Hedtmann: Orthopädie und Orthopädische Chirurgie, 1.Auflage, Thieme Verlag (2002), S.178-180

Author & Layout:

  • Achudhan Karunaharamoorthy
  • Christopher A. Becker

Illustrators:

  • Major Pectoralis Muscle - Yousun Koh 
© Unless stated otherwise, all content, including illustrations are exclusive property of Kenhub GmbH, and are protected by German and international copyright laws. All rights reserved.
Ventral trunk
Ventral trunk
The ventral trunk consists of a group structures, including bones and muscles, which define the anterior walls of the abdomen and thorax. All structures defining the v...
Video count a3db2d98fd28cfd1cd99caddadbde5f907d1e3a493a993db189771b177a2d04f 13 Quiz count 06cd7644291a9e7c4823c938df7a5e5046355b925d999aa0dba2a29a21ef4670 7 Atlas count 29cd72e1d0a4b1f73b30557f7146817906eed0d1c95938cf1dec8ac994772ae5 82 Article count 96ad6c28973916e23cd894dc46f79bb41858ac566ecb5c631f36d6f1f22bd235 78
  1. Bones of the ventral trunk
    Bones
  2. Clavicle
    Bones
  3. Muscles of the ventral trunk
    Muscles
  4. Muscles of the ventral trunk II
    Muscle Facts
  5. Neurovasculature of the ventral trunk
    Arteries
    Veins
    Nerves
  6. Inguinal canal
    Ligaments
    Arteries
    Nerves
  7. Ventral trunk
    Question Bank
Shoulder and arm
Shoulder and arm
The shoulder is one of the largest joints in the body and connects the arm to the trunk. The upper arm is greatly defined by the humerus. Here we will learn all about ...
Video count a3db2d98fd28cfd1cd99caddadbde5f907d1e3a493a993db189771b177a2d04f 28 Quiz count 06cd7644291a9e7c4823c938df7a5e5046355b925d999aa0dba2a29a21ef4670 7 Atlas count 29cd72e1d0a4b1f73b30557f7146817906eed0d1c95938cf1dec8ac994772ae5 77 Article count 96ad6c28973916e23cd894dc46f79bb41858ac566ecb5c631f36d6f1f22bd235 105
  1. Humerus and Scapula
    Bones
    Ligaments
  2. Muscles of arm and shoulder
    Muscles
  3. Neurovasculature of upper arm and shoulder
    Arteries
    Veins
    Nerves
  4. Muscles of the Shoulder
    Muscle Facts
  5. Rotator cuff muscles
    Muscle Facts
  6. Muscles of the Arm
    Muscle Facts
  7. Shoulder and arm
    Question Bank
Female breast
Female breast
The breasts are paired milk-producing organs found in the upper ventral, left and right sides of the torso. They contain the mammary glands which can secrete milk used...
Video count a3db2d98fd28cfd1cd99caddadbde5f907d1e3a493a993db189771b177a2d04f 0 Quiz count 06cd7644291a9e7c4823c938df7a5e5046355b925d999aa0dba2a29a21ef4670 2 Atlas count 29cd72e1d0a4b1f73b30557f7146817906eed0d1c95938cf1dec8ac994772ae5 27 Article count 96ad6c28973916e23cd894dc46f79bb41858ac566ecb5c631f36d6f1f22bd235 3
  1. Female breast structure
    Organs
  2. Blood vessels of female breast
    Arteries
    Veins

You might be also interested in the following articles

Create your free account.
Start learning anatomy in less than 60 seconds.