Anatomy

Question 1

Trapezius

Answer 1

Origin: all the thoracic spinous processes, the external occipital protuberance, the
ligamentum nuchae, and the spinous
process of C7

Inserts: Spine of the scapula.

Action: upward scapular rotation and posterior tipping during shoulder elevation.

Question 2

Serratus anterior

Answer 2

O: outer surface and
superior border of the upper 8th through 10th ribs and
the fascia of the associated external intercostal muscles.

I: anterior
surface of the vertebral border of the scapula

A: protract the scapula and it also assists with the force
coupling for normal scapular upward rotation and posterior
tipping. When the scapula is fixed, it is thought that
the serratus anterior will pull the ribs posteriorly.

Question 3

Pec Major

Answer 3

O:

• clavicular portion- originates off of the medial third of the clavicle and inserts at the lateral lip of the bicipital groove;
• sternal portion:
  - originates off of the superior 2/3 of the sternum and the manubrium, as well as the superior ribs;

I: Lateral lip of the bicipital groove;

• sternal costal portion:
  - originates off the distal edge of the sternum and 5th and 6th ribs;

A: muscle is to adduct and internally rotate the humerus. The clavicular portion of the pectoralis can also assist the
coracobrachialis and anterior deltoid with glenohumeral
flexion. When the distal attachment is fixed with the humerus
flexed, the pectoralis muscle will tend to pull the rib cage anteriorly, superiorly, and laterally

Question 4

Pec minor

Answer 4

anterior and superior surfaces of ribs
3 through 5 and attaches to the medial superior coracoid
process of the scapula

A:

Question 5

Anterior scalene

Answer 5

O: Ant tuberble of TP of C3-6.
I: Scalene tubercle on the inner border of the 1st rib.

Question 6

Middle scalene

Answer 6

O: TP of C2-7.
I: 1st rib medial to ant scalene.

Question 7

Posterior scalene

Answer 7

O: posterior tubercle of TP C4-6
I: outer surface of the 2nd rib.