1. Classification of muscles of the trunk

2. Figure 4.1 2

3. Section 2 The Muscles of Trunk 
Section 2 The Muscles of Trunk . The muscles of back trapezius, latissimus, levattor scapulae, rhomboid muscles erector spinae (sacrospinelis) thoracolumbar fascia . The muscles of thorax 1) The extrinsic muscles pectoralis major, pectoralis minor, serratus anterior 2) The intrinsic muscles intercostales extrerni, intercostales interni  . The diaphragm  . The muscles of abdomen 3

4. 4

5. Muscles of Thorax Muscle Origin Insertion Action Innervation
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Muscles of Thorax
Muscle
Origin
Insertion
Action
Innervation
Pectoralis major
Sternum, Ribs 2-6
Inter-tubercular groove of humerus
Adduct, Flex, Med Rotate Arm
M & L pectorals
Pectoralis minor
Ribs 3-5
Coracoid process of scapula
Depress, Rotate scapula
Serratus anterior (ventralis)
Ribs 1-9
Scapula
Protract, Rotate scapula
Long Thoracic

6. Muscles of Thorax Muscle Origin Insertion Action Innervation Trapezius
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Muscle
Origin
Insertion
Action
Innervation
Trapezius
Ligamentum nuchae, C7-T12
Clavicle, Spine & acromion of scapula
Elevate, Adduct, Rotate, Depress
Accessory
Levator Scapulae
C1-C4
Medial border of scapula
Elevate scapula
D. Scapular
Rhomboids
C7-T5
Adduct, Elevate, Rotate

7. Muscles of Thorax Muscle Origin Insertion Action Innervation Deltoids
Clavicle, Spin & acromion of scapula
Deltoid tuberosity of humerus
Flex, Abduct, Extend, Lat & med. rotate arm
Axillary
Latissimus dorsi
Iliac crest,
Sacrum, T7-12, Lumbar fascia
Inter-tubercular groove of humerus
Extend, Adduct, Med. rotate arm
Thoraco-dorsal

8. Anterior Surface of Thorax
Palpate the following
Sternum (3 parts)
Jugular notch
Sternal Angle (= 2nd rib)
Clavicle
Costal margin
Xiphosternal joint
Midclavicular Line
Midaxillary Line
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9. Posterior Surface of Thorax
Palpate the following
Spinous Process of C7
Scapula (ribs 2-7)
Scapular spine
Acromion Process
Inferior Angle of Spine
Inferior Border
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10. Locating Internal Structures
Pleural Cavities
Inferior margin = adjacent to T12 in Posterior Midline
To Rib 10 at Midaxillary line
To Rib 8 at Midclavicular line
To Xiphosternal joint medially
Lungs posterior border is 2 ribs superior to pleural cavity (rib 8)
Heart
Deep to xiphisternal angle
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11. 11

12. 12

13. 13

14. Pectoralis Major
Pectoralis Minor

15. Trapezius
In more primitive species used for opening and closing gills - a
BRANCHIAL muscle.
In humans, used to move scapula and keep head up

16. Trapezius Origin: Occipital bone, Spines of C7 and T1-12 Insertion:
Acromion
Spine of scapula
Lateral 1/3 of clavicle

17. Trapezius Innervation: Accessory Nerve (Cranial Nerve XI) Action:
Extension of the head
Elevation and depression of scapula

18. Trapezius

19. Serratus Anterior Origin: First 9 ribs Insertion:
Medial edge of scapula’s deep surface

20. Serratus Anterior Innervation: Long thoracic nerve Action:
Rotates scapula
Primitively a BODY WALL MUSCLE

21. Serratus
Anterior

22. Levator Scapulae Origin: Transverse processes of C1-4 Insertion:
Medial edge of scapula

23. Levator Scapulae Innervation: Ventral Rami of C3 and C4 Action:
Retracts scapula Depresses glenoid

24. Rhomdoidius Major Origin: Spines of T2-T5 Insertion:
Medial edge of scapula

25. Rhomdoidius Major Innervation: Dorsal Scapula Action:
Retracts scapula Depresses glenoid

26. Rhomdoidius Minor Origin: Spines of C7 and T1 Insertion:
Medial edge of scapula
Note: minor is superior (cranial), but SMALLER

27. Rhomdoidius Minor Innervation: Dorsal Scapula Action:
Retracts scapula Depresses glenoid

28. Levator Scapulae
Rhomboid Minor
Rhomboid Major

29. Levator Scapulae
Depression
Rhom-
boids
Pecoralis
Minor

30. Elevation
Trapezius
Serratus
Anterior
Trapezius

31. Latissimus Dorsi Origin: Spines of T7-T12 Thoracolumbar fascia
Insertion:
Humerus: Inertubecular groove
And lesser tubecular crest
Innervation:
Thoracodorsal Nerve

32. Latissiumus: Extends, adducts and medially rotates humerus
Pectoralis: is large, fan-shaped muscle opposing it ventrally

33. Pectoralis Major: Clavicular Head: Sternal Head:
Origin: inferior margin of clavicle
Insertion: Delto-pectoral crest of HUMERUS
Sternal Head:
Origin: Ventro-lateral margin of sternum

34. Pectoralis Major: Clavicular Head: Origin: inferior margin of clavicle
Insertion: Greater tubercular crest of HUMERUS
Innervation: Medial and lateral pectoral nerves

35. Pectoralis Major: Sternal Head: DEPRESSOR, ADDUCTOR of humerus
Origin: Ventro-lateral margin of sternum; costal cartilages 1-6
Insertion: Greater tubercular crest of HUMERUS
Innervation: Medial and lateral pectoral nerves

36. Pectoralis MINOR: Deep to Pec. Major Origin:Ribs 3-6.
Insertion: Coracoid Process of Scapula
Innervation:
Function: Stabilization of scapula
Positionally important for understanding location of other structures.

37. Elevators Teres Major Origin: Lower edge of scapula
Insertion: Lesser tubercular crest
Action: Extends, Adducts & Medially rotates humerus
Innervation: Lower scapular

38. Elevators Subscapularis Origin: Deep surface of scapula
Insertion: Lesser tubercle
Action: Medially rotates humerus
Innervation: Upper and lower scapular

39. Internal View:
Subscapularis

41. Elevators Teres Minor Origin: Lower edge of scapula
Insertion: Greater tubercle
Action: Laterally rotates humerus
Innervation: Axillary

42. Teres Minor