Muscles of thorax

This is a presentation on muscles of thorax with their Origin, insertion, nerve supply & action. Hope it will help you guys. Thank you.

1. Muscles of Thorax Origin, Insertion, Nerve supply and Action Abid Hasan Khan

2. Presented by Abid Hasan Khan Roll no: 30 Year : 2nd Session : 2015-16 Department of Physiotherapy Bangladesh Health Professions Institute (BHPI), CRP- Chapain , Savar , Dhaka – 1343. Abid Hasan Khan

3. Surface Muscles (Anterior) Platysma Pectoralis major Pectoralis minor Subclavius Serratus anterior Abid Hasan Khan

4. Platysma Origin: Skin over lower neck and upper lateral chest. Insertion: Inferior border of mandible and skin over lower face and angle of mouth. Nerve Supply: Cervical branch of facial nerve (VII) Action: Depresses and wrinkles skin of lower face and mouth. Aids forced depression of mandible Abid Hasan Khan

5. Pectoralis major Origin: Clavicular Head :  Anterior surface of the medial half of the clavicle . Sternal Head :  Lateral aspects of the manubrium and body of the sternum, the upper six costal cartilages and the aponeurosis of the abdominal oblique. Insertion:   Clavicular Head :  Lateral lip of the bicipital groove of the humerus and anterior lip of the deltoid tuberosity. Abid Hasan Khan

6. Pectoralis major (Conts..) Sternal Head: Lateral lip of the bicipital groove of the humerus and the anterior lip of the deltoid tuberosity . Nerve Supply: Medial pectoral nerve (C7, T1) and lateral pectoral nerve (C5, 6, 7 ). Action :   Shoulder flexion, Internal rotation , Adduction. Abid Hasan Khan

7. Pectoralis minor Origin :  Anterior surfaces of the third to fifth ribs. Insertion :  Via a tendon to the medial aspect of the coracoid process of the scapula. Part or all of the tendon may transverse this process and continue into the coracoacromial ligament . Nerve supply :   Medial pectoral nerve (C7, T1 ) Action :  Scapula protraction, rotation of the scapula downwards. Abid Hasan Khan

8. Subclavius Origin :  From the junction of the first rib and its costal cartilage, just anterior to the costoclavicular ligament. Insertion :  By muscular fibers to the groove on the inferior surface of the middle of the clavicle. Nerve supply :   Subclavian branch of brachial plexus (C5, C6 ). Action: Depression of clavicle. Abid Hasan Khan

9. Serratus anterior Origin: Fleshy slips from the lateral aspect of the superior eight ribs and anterior intercostal membranes from the midclavicular line, the lower four slips interdigitating with external abdominal oblique. Insertion:   Volar surface of the axillary border of the scapula, spanning the superior and inferior angles. Abid Hasan Khan

10. Serratus anterior (Conts..) Nerve supply: Long thoracic nerve (C5, 6, 7 ). Action:   Protracts and stabilizes scapula, assists in upward rotation. Abid Hasan Khan

11. Surface Muscles (Posterior) Latissimus dorsi Trapezius Rhomboideus major Rhomboideus minor Abid Hasan Khan

12. Latissimus Dorsi Origin:   Spinous processes of thoracic T7-T12 , 9th to 12th ribs, the lumbar and sacral vertebrae (via the thoracolumbar fascia ), and the posterior third of the external lip of the iliac crest. Occasionally by a slip from the posterior surface of the inferior angle of the scapula . Abid Hasan Khan

13. Latissimus Dorsi (Cont..) Insertion: Bottom of intertubercular (bicipital) groove of humerus. Nerve supply: Thoracodorsal nerve (C6 – C8 ). Action: Extends, adducts, and medially rotates the arm; draws the shoulder downward and backward; keeps inferior angle of scapula against the chest wall; accessory muscle of respiration. Abid Hasan Khan

14. Trapezius Origin: Upper part: External occipital proturberance , medial third of the superior nuchal line, the ligamentum nuchae,  and the spinous process of C7. Medial Part:   Spinous processes of T1 to T5. Lower Part:   Spinous processes of T6 to T12. Abid Hasan Khan

15. Trapezius (Cont..) Insertion : Upper Part: Lateral third of the clavicle and the medial aspect of the acromion process of the scapula. Middle Part:   Medial edge of the superior surface of the acromion process of the scapula and the superior edge of the scapular spine. Lower Part: Tubercles of the apex of the scapular spine. Nerve supply: Spinal Accessory Cranial XI , Ventral Rami C2-C4. Action: Upper Part:   Upward rotation of the scapula, elevation of the scapula Middle Part : Retraction of the scapula. Lower Part: Upper rotation of the scapula, depression of the scapula. Abid Hasan Khan

16. Rhomboideus major Origin:   Spinous processes of T2 – T5. Insertion: Vertebral border of the scapula, from inferior to the scapular spine to the inferior angle. Nerve supply: Vertebral border of the scapula , from inferior to the scapular spine to the inferior angle. Action: Retraction of the scapula, downward rotation of the scapula. Abid Hasan Khan

17. Rhomboideus minor Origin: Ligamentum Nuchae and the spinous processes of C7 and T1. Insertion: Vertebral border of the scapula, adjacent to the scapular spine . Nerve supply: Dorsal scapular nerve C5. Action: Retraction of  the scapula, downward rotation of the scapula. Abid Hasan Khan

18. Intercostal Muscles External Intercostals Origin: Lower margin of upper eleven ribs. Insertion: Superior border of rib below ( each muscle fiber runs obliquely and inserts toward the costal cartilage ). Nerve supply: Intercostal nerves. Action: Draw ventral part of ribs upward , increasing the volume of the thoracic cavity for inspiration. Abid Hasan Khan

19. Intercostal Muscles (Conts..) Internal Intercostals Origin: From the cartilages to the angles of the upper eleven ribs. Insertion: Superior border of the rib below (each muscle fiber runs obliquely and inserts away from the costal cartilage ). Nerve supply: Intercostal nerves. Action: Draw ventral part of ribs downward, decreasing the volume of the thoracic cavity for expiration. Abid Hasan Khan

20. Rotator Cuff Muscles Supraspinatus Infraspinatus Teres Minor Subscapularis Abid Hasan Khan

21. Supraspinatus Origin:   Supraspinous fossa of scapula. Insertion: Superior facet of greater tubercle of humerus. Nerve supply: Suprascapular nerve (C5,6 ). Action:   Abduction of arm and stabilizes Humerus. Abid Hasan Khan

22. Infraspinatus Origin:   Infraspinous fossa of the scapula. Insertion: Middle facet of greater tubercle of the humerus. Nerve supply: Suprascapular Nerve (C5, 6 ). Action: External rotation of arm, stabilizes Humerus. Abid Hasan Khan

23. Teres Minor Origin:   On the dorsal surface of the middle half of the lateral border of the scapula. Insertion: The lowest of the three facets of the greater tubercle of the humerus. Nerve supply: Axillary nerve (C5,6 ). Action: Externally rotates the arm.   Abid Hasan Khan

24. Subscapularis Origin:   Medial two-thirds of  volar surface of the scapula. Insertion:   Lesser tubercle of humerus. Nerve supply:   Upper and Lower Subscapular Nerve (C5,6 ). Action:  Internally rotates humerus; Assists with depression of the humeral head. Abid Hasan Khan

25. Thank You Abid Hasan Khan