Muscles of the pectoral girdle PART 2 (dave's notes)

Question 1

What is the origin of lat dorsi?

Answer 1

All thoracic spines and supraspinous ligaments from T7 down, and L/S spines?? via lumbar fascia, posterior 1.3rd of the iliac crest, lower 4 ribs (id with EOM)
Migrates out

Question 2

What is the insertion of lat dorsi?

Answer 2

Floor of bicipital groove of humerus after spiralling around teres major

Question 3

What is the action of lat dorsi?

Answer 3

Extends, adducts and medially jrotates the arm. The costal attachment helps with deep inspiration and expiration

Question 4

What is the nerve to lat dorsi?

Answer 4

The thoracodorsal from the posterior cord

Question 5

What is the origin and insertion of rhomboid major?

Answer 5

The spines of T2-T5 and the supraspinous ligaments

to the lower 1.2 of the posteriomedial border of the scapula

Question 6

What is the action of rhomboid major? Innervation?

Answer 6

retracts scapula and rotates to rest position. Dorsal scapular nerve C5 from root

Question 7

What is the origin and insertion of rhom minor?

Answer 7

The lower ligamentum nuchae, spines of C7/T1 to a small area posteriomedial border of the scapular at the level of the spine

Question 8

What is the action and innervation of rhom minor?

Answer 8

Retracts scapula and rotates to rest postion - same as major

Nerve is dorsal scapular nerve C5 from root - same as major

Question 9

What is the action and innervation of levator scapulae?

Answer 9

Raises medial border of scapula. Innervated by the anterior primary rami of C3 and C4 and the dorsal scapular nerve. Migrates in.

Question 10

What is the origin and insertion of levator scapulae?

Answer 10

Originates from the posterior tubercle of the transverse processes of C1-4, inserts to the upper part of the medial border of the scapula

Question 11

What is the origin and insertion of serratus anterior?

Answer 11

Upper 8 ribs and anterior intercostal membranes from the mode clavicular line
to the inner medial border of the scapula - 1 and 2 upper ankle
3 and 4 to the costal margin
5-8 to the inferior angle

Question 12

What is the action of serratus anterior

Answer 12

laterally rotates and protracts? the scapula

Question 13

What is the innervation of serratus anterior?

Answer 13

The long thoracic nerve with 1 and 2 C5, 3 and 4 C6, 5-8 C7