Muscles of Scapular and Pectoral Regions Flashcards
Pectoralis Major
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Middle clavicle, sternum to 7th rib, cartilages of true ribs
- Distal Attachment: Lateral lip of intertubercular sulcus of humerus
- Action: Flexes and adducts arm, rotates arm medially
- Innervation: Medial and lateral pectoral nerve
- Blood Supply: Thoracoacromial artery (pectoral branch)
Pectoralis Minor
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Ribs 3-5
- Distal Attachment: Coracoid process of scapula
- Action: Lowers lateral angle of scapula, protracts scapula
- Innervation: Medial scapula nerve
- Blood Supply: Thoroacromial artery (pectoral branch)
Serratus Anterior
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Lateral surface of upper 8-9 ribs
- Distal Attachment: Medial border of scapula (costal side)
- Action: Protracts and rotates scapula, holds scapula against thoracic wall
- Innervation: Long thoracic nerve
- Blood Supply: Lateral thoracic artery
Subclavius
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Upper border of 1st rib
- Distal Attachment: Inferior surface of middle 1/3 clavicle
- Action: Anchors and depresses clavicle
- Innervation: Nerve to subclavius
- Blood Supply: Thoracoacromial artery (clavicular branch)
Deltoid
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Lateral third of anterior clavicle, lateral acromion, inferior edge of spine of scapula
- Distal Attachment: Deltoid tuberosity of humerus
- Action: Flexes and medially rotates arm; abducts arm beyond initial 15˚, extends and laterally rotates arm
- Innervation: Axillary nerve
- Blood Supply: Posterior humeral circumflex, thoracoacromial artery (deltoid branch)
Teres major
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Posterior surface of inferior angle of scapula
- Distal Attachment: Medial lip of intertubercular sulcus of humerus
- Action: Adducts and medially rotates arm
- Innervation: Lower subscapular nerve
- Blood Supply: Circumflex scapular artery
Supraspinatus
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Supraspinous fossa of scapula
- Distal Attachment: Superior facet of greater tubercle of humerus
- Action: Initiates arm abduciton first 15˚, works with rotator cuff
- Innervation: Suprascapular nerve
- Blood Supply: Suprascapular artery
Infraspinatus
Proximal Attachement
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Infraspinous fossa of scapula
- Distal Attachment: Middle facet of greater tubercle of humerus
- Action: Lateral rotation of arm
- Innervation: Suprascapular nerve
- Blood Supply: Suprascapular artery
Teres Minor
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Supply
- Proximal Attachment: Upper 2/3 of posterior surface of lateral border of scapula
- Distal Attachment: Inferior facet of greater tubercle of humerus
- Action: Laterally rotates arm
- Innervation: Axillary nerve
- Blood Supply: Circumflex scapular artery
Subscapularis
Proximal Attachment
Distal Attachment
Action
Innervation
Blood Suppy
- Proximal Attachment: Subscapular fossa
- Distal Attachment: Lesser tubercle of humerus
- Action: Medially rotates arm at shoulder and adducts arm
- Innervation: Upper and lower subscapular nerves
- Blood Supply: Subscapular artery, lateral thoracic artery
Quadrangular Space
Superior, Inferior, Medial, Lateral Borders
Contents
- Superior Border: Teres minor
- Inferior Border: Teres major
- Medial Border: Long head of triceps brachii
- Lateral Border: Surgical neck of humerus
- Contents:
- Axillary nerve
- Posterior humeral circumflex artery/vein
