muscles of the anterior trunk

Question 1

what is this muscle? Origin? Insertion? Action?

Answer 1

pectoralis major

origin: clavicle, sternum, ribs
insertion: humerus
action: flex and medial rotate the arm

Question 2

what is this muscle? Origin? Insertion? Action?

Answer 2

pectoralis minor

origin: ribs
insertion: scapula
action: elevates ribs and moves scapula forwards

Question 3

what is this muscle? Origin? Insertion? Action?

Answer 3

external intercostal

origin: inferior border of superior rib
insertion: superior border of inferior rib
action: elevate rib cage + inhalation

Question 4

what is this muscle? Origin? Insertion? Action?

Answer 4

internal intercostal

origin: superior border of inferior rib
insertion: inferior border of superior rib
action: depress rib cage + expiration

Question 5

what is this muscle? Origin? Insertion? Action?

Answer 5

rectus abdominus

origin: pubic symphysis
insertion: ribs
action: flex and rotate vertebral column

Question 6

what is this muscle? Origin? Insertion? Action?

Answer 6

external abdominal oblique

origin: external surface of lower ribs
insertion: pubic crest + iliac crest
action: trunk rotation

Question 7

what is this muscle? Origin? Insertion? Action?

Answer 7

Internal abdominal oblique

origin: iliac crest
insertion: ribs + pubic crest
action: trunk rotation

Question 8

what is this muscle? Origin? Insertion? Action?

Answer 8

transverse abdominis

origin: iliac crest
insertion: pubic crest
action: compress abdomen