Scapula and Deltoid Regions Flashcards
Skeletal Elements of Pectoral Girdle
Scapula, Clavicle, *Humerus not considered part*
Joints of the Shoulder Region: Ligament Reinforced
Coracoclavicular: A: Trapezoid B: Conoid Coracoacromial Superior Glenohumeral Middle Glenohumeral Inferior Glenohumeral
Scapular Motion
Elavation/Depression Protraction/Retraction Upward/Downward Rotation
Deltoid
Origin: lateral 1/3 of clavicle, acromion, spine of scapula Insertion: deltoid tuberosity of humerus Axns: At humerus Flex Medially Rotate Abduct Extend Laterally Rotate Blood Supply: deltoid branch of thoracoacromial arterial trunk Innervation: Axillary nerve (C5-6)
Teres Major
Origin: Post. surface of inf. angle of scapula Insertion: med. lip of intertubercular groove of humerus Axns: at humerus Adduct Medially Rotate Blood Supply: circumflex scapular artery Innervation: lower subscapular nerve (C5-6)
Serratus Anterior
Origin: Ext. surface of lateral part of ribs 1-9 Insertion: Ant. surface of medial border of scapula Axns: Protracts scapula Holds scapula to thoracic wall Rotates scapula Blood Supply: Lateral Thoracic Artery Innervation: Long Thoracic Nerve (C5-7)
Muscles of the Rotator Cuff
Supraspinatus Infraspinatus Subscapularis Teres Minor
Supraspinatus
Origin: Supraspinous fossa of scapula
Insertion: sup. facet of greater tubercle of humerus
Axns: Abduction of humerus
Stabilize shoulder joint
Blood supply: Suprascapular artery
Innervation: Suprascapular nerve (C4-7)
Shoulder Impingement
Supraspinatus tendonitis
Greater than 90º angle compresses SS tendon
can involve subacromial bursa
SS can also tear
Subscapularis
Origin: subscapular fossa (ant. surface)
Insertion: lesser tubercle of humerus
Axns: medially rotates humerus
adducts humerus
hold humeral head in place
Blood Supply: subscapular artery
Innervation: upper & lower subscapular nerves (C5-7)
Subscapularis
Largest Rotator Cuff Muscle: tears are rare: tendonitis common
Injury leads to bicipital tendon instability/tendonitis
Passes over biceps tendon
Origin: Infraspinous fosssa
Insertion: middle facet of greater tubercle of humerus
Axns: laterally rotates humerus
holds humeral head in place
Blood Supply: suprascapular artery
Innervation: suprascapular nerve (C5-6)
Teres Minor
Origin: Middle part of lateral border of scapula
Insertion: Inf. facet of greater tubercle of humerus
Axns: lat. rotate humerus
hold humeral head in place
Blood: circumflex scapular artery
Nerve: axillary nerve (C5-6)
Initiates abduction to 15º
Circulation: Subclavian Artery
Origin:
Right: brachiocephalic trunk
Left: Aortic arch
arises posterior to sternoclavicular joint
3 divisions in relation to ant. scalene muscle
Part 1: medial to it
Part 2: posterior to it
Part 3: lateral to it
Medial Part of Subclavian Artery
Branches:
Internal thoracic (mammary) a.
Vertebral a.
Thyrocervical arterial trunk
Thyrocervical Arterial Trunk:
Consists of:
Tranverse Cervical artery: superficial and deep branch
deep branch is dorsal scapular artery
Inferior thyroid artery
ascending cervical artery
suprascapular artery
Posterior Part of Subclavian Artery Branches
Costocervical arterial trunk
supreme intercostal artery
deep cervical artery
Lateral Part of Subclavian Artery: No branches
Dorsal Scapular may arise from it
Subclavian becomes axillary at lateral border of 1st rib
Scapular Anastomoses
Suprascapular artery
Dorsal Scapular artery
Posterior Intercostal arteries
Circumflex Scapular artery
Thoracodorsal artery
Dorsal Scapular Artery Note
Can arise from subclavian
Can arise from transverse cervical (30% of time)
called deep branch of transverse cervical
Runs along vertebral border of scapular
Be able to draw venous drainage and arteries
Relationships and Spaces
Traingle of Auscultation
Quadrangular Space: axillary nerve & post. circumflex humeral artery
Triangular Space: circumflex scapular artery
Triangular Interval: deep brachial artery and radial nerve
