MCB 150 Lecture 8: Muscles of the shoulder and scapula

• School: University of Illinois
• Department: Molecular and Cell Biology
• Course: MCB 150
• Professor: B Mehrtens

Document Summary

Action: agonist in scapula protraction (abducts); rotates scapula superiorly (glenoid cavity moves superiorly); stabilizes scapula. Insertion: costal surface of medial border of scapula. Action: elevates scapula; rotates scapula inferiorly (moves glenoid cavity. Origin: transverse processes of cervical vertebrae 1-4. Insertion: upper of medial border of scapula. Action: elevates & retracts (adducts) scapula; rotates. Origin: ligamentum nuchae, spinous process of vertebrae scapula inferiorly. Origin: external occipital protuberance, superior nuchal line, ligamentum nuchae. Insertion: lateral of clavicle and acromion of scapula. Insertion: medial border of acromion, superior lip of spine of scapula. Anterior fibers: flex and medially rotate arm. Posterior fibers: extend & laterally rotate arm. Posterior: inferior border of spine of scapula. Insertion: greater tubercle of humerus & capsule of shoulder joint. Origin: posterior surface of lateral border of scapula. Action: adducts arm, medially rotates arm & extends arm. Origin: posterior surface of inferior angle and lower of lateral border of scapula.