1. PECTORAL , BACK AND SCAPULAR REGION
Dr.Lubna Nazli

2. OBJECTIVES At the end of the lecture students should know:
Muscles of the pectoral region.
Clavipectoral fascia.
Muscles of the back – layer 1
layer 2
4. Muscles attached to scapula
5. Rotator cuff
6. Quadrangular space &Triangular spaces.
7. Nerves of scapular region.
8. Arteries of scapular region.
9. Anastomosis around the scapula.
Applied anatomy.

3. Pectoral region Muscles of the Pectoral Region pectoralis major
pectoralis minor
subclavius
And Serratus
anterior.

4. Pectoralis major
ORIGIN medial half of clavicle sternum, costal cartilages aponeurosis of external oblique muscle
INSERTION lateral lip of intertubercular groove of humerus
ACTION flexes, adducts, and rotates arm medially
NERVE medial and lateral pectoral nerves of brachial plexus

5. Pectoralis minor ORIGIN ribs 3-5
INSERTION coracoid process of the scapula
ACTION draws the scapula forward, medialward, and downward
NERVE medial pectoral nerve of brachial plexus

6. Subclavius ORIGIN junction of the 1st rib with its costal cartilage
INSERTION inferior surface of clavicle
ACTION pulls clavicle towards the sternum
NERVE nerve to subclavius of brachial plexus

7. Serratus anterior ORIGIN ribs 1-8 or 9
INSERTION medial border of the scapula on its costal (deep) surface
ACTION it draws the scapula forward
NERVE long thoracic nerve (from ventral rami C5-C7)
IMP: a lesion of long thoracic nerve will cause winging of the scapula

8. Clavipectoral fascia
The deep fascia which extends between subclavius, coracoid process and pectoralis minor muscles
The structures passing through the clavipectoral fascia
Cephalic vein
Thoracoacromial artery
Lateral pectoral nerve
Lymphatics

9. Clavipectoral fascia

10. Muscles of the back are arranged in 2 layers
Layer 1 – trapezius
latissimus dorsi
Layer 2 – levator scapulae
rhomboid minor
rhomboid major

11. TRAPEZIUS
ORIGIN Medial third superior nuchal line, ligamentum nuchae, spinous processes and supraspinous ligaments to T12
INSERTION Upper fibers to lateral third of posterior border of clavicle; lower to medial acromion and superior lip of spine of scapula.
ACTION laterally rotates, elevates and retracts scapula.
NERVE Spinal accessory nerve (C1-5)

12. LATISSIMUS DORSI
ORIGIN Spine T7, spinous processes and supraspinous ligaments of all lower thoracic, lumbar and sacral vertebrae, lumbar fascia, posterior third iliac crest, last four ribs and inferior angle of scapula
INSERTION Floor of bicipital groove of humerus.
ACTION Extends, adducts and medially rotates arm.
NERVE Thoracodorsal nerve (C6, 7, 8) (from posterior cord)

13. LEVATOR SCAPULAE
ORIGIN Posterior tubercles of transverse processes of C1-4
INSERTION Upper part of medial border of scapula
ACTION Raises medial border of scapula
NERVE Anterior primary rami of C3 and C4 and dorsal scapular nerve (C5)

14. RHOMBOID MINOR ORIGIN Lower ligamentum nuchae, spines of C7 and T1
INSERTION On posteromedial border of scapula at level of spine, below levator scapulae
ACTION Retracts scapula.
NERVE Dorsal scapular nerve (C5) (from root)

15. RHOMBOID MAJOR ORIGIN Spines of T2-T5 and supraspinous ligaments
INSERTION Lower half of posteromedial border of scapula, from angle to upper part of triangular area at base of scapular spine
ACTION Retracts scapula.
NERVE Dorsal scapular nerve (C5) (from root )

16. Revise

17. Identify these muscles

18. Muscles attached to scapula
The muscles which join the scapula to the humerus are:
Deltoid
Supraspinatus
Infraspinatus
Teres minor
Teres major
Subscapularis

19. DELTOID
ORIGIN Lateral third of clavicle, acromion, spine of scapula to deltoid tubercle.(multipennate muscle)
INSERTION Middle of lateral surface of humerus (deltoid tuberosity)
ACTION Abducts arm, anterior fibers flex and medial rotate, posterior fibers extend and lateral rotate
NERVE Axillary nerve (C5, 6) (from posterior cord)
IMPORTANCE
Site of intramuscular injection.

20. SUPRASPINATUS
ORIGIN Medial three quarters of supraspinous fossa of scapula.
INSERTION Superior facet on greater tuberosity of humerus and capsule of shoulder joint
ACTION Abducts arm and stabilizes shoulder joint
NERVE Suprascapular nerve (C5, 6)(from upper trunk)

21. INFRASPINATUS
ORIGIN Medial three quarters of infraspinous fossa of scapula.
INSERTION Middle facet of greater tuberosity of humerus and capsule of shoulder joint
ACTION Laterally rotates arm and stabilizes shoulder joint
NERVE Suprascapular nerve (C5, 6 ) (from upper trunk)

22. TERES MINOR
ORIGIN Middle third lateral border of scapula above teres major
INSERTION Inferior facet of greater tuberosity of humerus (below infraspinatus) and capsule of shoulder joint
ACTION laterally rotates arm and stabilizes shoulder joint
NERVE Axillary nerve (C5, 6) (from posterior cord)

23. TERES MAJOR
ORIGIN Oval area on lateral side of inferior angle of scapula below teres minor.
INSERTION Medial lip of bicipital groove of humerus
ACTION Medially rotates and adducts arm. Stabilizes shoulder joint
NERVE Lower subscapular nerve (C5, 6) (from posterior cord)

24. SUBSCAPULARIS ORIGIN Medial two thirds of subscapular fossa
INSERTION Lesser tuberosity of humerus.
ACTION Medially rotates arm and stabilizes shoulder joint
NERVE Upper and lower subscapular nerves (C5,6) (from posterior cord)

25. Revise :

26. ROTATOR CUFF ( Musculotendinous cuff )
The tendons of four muscles form the rotator cuff.
The muscles are:
Supraspinatus.
Infraspinatus.
Teres minor.
Subscapularis.

28. Intermuscular spaces Quadrangular space Triangular spaces
Boundaries of quadrangular space:
Above: teres minor & subscapularis
Below: teres major
Medially: long head of triceps
Laterally: surgical neck of humerus
Transmits: axillary nerve & posterior circumflex humeral vessels.

31. Triangular space ( upper ) bounded by:
Above: teres minor
Below: teres major
Laterally: long head of triceps
Transmits: circumflex scapular vessels
Triangular space ( lower ) bounded by:
Above: teres major
Medially: long head of triceps
Laterally: medial head of triceps
Transmits: radial nerve and profunda brachii artery

32. Nerves of scapular region
Upper subscapular nerve – supplies subcapularis.
Lower subscapular nerve – supplies subscapularis and teres major.
3. Suprascapular nerve – supplies supraspinatus & infraspinatus.
4. Axillary nerve – supplies deltoid & teres minor.

33. Arteries of scapular region
The arteries seen are:
Transverse cervical artery.
Suprascapular artery.

34. Anastomosis around the scapula:
The scapular anastomosis connects subclavian artery and the axillary artery, forming an anastomosis around the scapula. It allows blood to flow past the joint regardless of the position of the arm.

35. Applied anatomy
A rotator cuff injury is an injury to 1 or more of the 4 muscles in the shoulder. It can be associated with a fall.
The type of injury can range from an inflammation of the muscle without any permanent damage, such as tendinitis, to a complete or partial tear of the muscle that might require surgery to fix it.