a. Which of the muscles on the dorsal surface are shaped like a trapezoid?
b. What bones along the dorsal midline are points of attachment for the acromiotrapezius, spinotrapezius, and latissimus dorsi?
c. Are the bones named in your previous answer sites of the origin or insertion of these muscles?
d. Which muscle is antagonistic to the biceps brachii?
e. Is the biceps brachii an extensor or a flexor?
f. Is the latissimus dorsi a retractor or protractor?