Scapulohumeral (Intrisic Shoulder) Muscles

Question 1

Deltoid

Answer 1

Clavicular (anterior) part flexes and medially rotates shoulder joint; acromial (middle) part abducts shoulder joint; spinal (posterior) part extends and laterally rotates shoulder joint
nerve supply - axillary nerve
attachment: lateral third of clavicle; acromion and spine of scapula -> deltoid tuberosity of humerus

Question 2

Supraspinatus

Answer 2

initiates and assists deltoid in abduction of shoulder joint and acts with other rotator cuff muscles
nerve supply - suprascapular nerve
attachment: supraspinous fossa of scapula -> greater tubercle of humerus

Question 3

Infraspinatus

Answer 3

laterally rotate shoulder joint; help hold humeral head in glenoid cavity of scapula
nerve supply - suprascapular nerve
attachement: infraspinous fossa of scapula -> greater tubercle of humerus

Question 4

Teres minor

Answer 4

laterally rotate shoulder joint; help hold humeral head in glenoid cavity of scapula
nerve supply - axillary nerve
middle part of lateral border of scapula -> greater tubercle of humerus

Question 5

Teres major

Answer 5

adducts and medially rotate shoulder joint
nerve supply - lower subscapular nerve
inferior part of lateral border of scapula and posterior surface of inferior angle of scapula -> medial lip of intertubercular sulcus of humerus