Muscles of the Axilla
Rahul's Noteblog Notes on Anatomy Notes on Shoulder Anatomy Muscles of the Axilla
Pectoral Muscles:
• Pectoralis Major.
• Pectoralis Minor.
Origin:
• Clavicular head; anterior surface of the medial half of clavicle.
• Sternocostal head; anterior surface of the sternum, superior six costal cartilages.
• 3rd to 5th ribs near their costal cartilages.
Insertion:
• Lateral lip of the intertubercular groove of humerus.
• Medial border of the superior surface of coracoid process of scapula.
Innervation:
• The lateral and medial pectoral nerves.
• Clavicular head (C5 and C6).
• Sternocostal head (C7, C8, T1).
• Medial pectoral nerve (C8 and T1).
Action:
• Adducts and medially rotates the humerus.
• Draws the scapula anteriorly and inferiorly.
• When acting alone, the clavicular head flexes the humerus while the sternocostal head extends it.
• Stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall.
Subclavius and Serratus Anterior:
Origin:
• Junction of the 1st rib and its costal cartilage.
• External surfaces of the lateral parts of 1st to 8th ribs.
Insertion:
• Inferior surface of the middle third of clavicle.
• Anterior surface of the medial border of scapula.
Innervation:
• Nerve to the subclavius (C5 and C6).
• Long thoracic nerve (C5, C6 and C7).
Action:
• Anchors and depresses the clavicle.
• Protracts the scapula and holds it against the thoracic wall.
• Rotates the scapula.
Chapters on Shoulder Anatomy:
1. Arteries of the Axilla
2. Arteries of the Shoulder Girdle
3. Axillary Artery Aneurysm
4. Axillary Fat and Fascia
5. Axillary Nerve Block
6. Bones and Fractures of the Upper Limb
7. Boundaries of the Axilla
8. Breast Cancer and Axillary Lymph Nodes
9. Erb-Duchenne Palsy
10. Joints of the Shoulder Girdle
11. Klumpke's Paralysis
12. Lymph Nodes of the Axilla
13. Muscles of the Axilla
14. Muscles of the Shoulder Girdle
15. Notes on Shoulder Bursae
16. Roots and Trunks of the Brachial Plexus
17. Winged Scapula in Computer Programmer
18. Transient Axillary Paralysis
19. Variation of Brachial Plexus Structure
20. Veins of the Axilla
Additional Reading:
Histology and Cytology
1. Cell Components
2. Nervous Tissue
3. Muscle Tissue
4. Lymphoid Tissue
5. Integument
6. Respiratory System
7. Gastrointestinal System
8. Renal/Urinary System
9. Male Reproductive System
10. Female Reproductive System
Gross Anatomy
1. Back and Nervous System
2. Thorax
3. Abdomen, Pelvis, and Perineum
4. Upper Limb
5. Lower Limb
6. Head and Neck
7. Chest Wall
8. Shoulder
Anatomy Videos
1. Video of Musculoskeletal Examination in a Clinical Setting
1. Video of HEENT Examination in a Clinical Setting
Related Topics
1. Jugular Venous Distention Workup
Medical Images
Useful Medical Images & Diagrams (link opens in a new window)
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