Muscles of the Axial Skeleton

Question 1

Sternocleidomastoid

Answer 1

Action: Lateral flexion, rotation of head, and flexion of neck

Origin: Sternal end of clavicle
Insertion: Mastoid process

Question 2

Erector spinae

Answer 2

Action: Flexes neck, maintains posture, and laterally flexes vertebral column

Origin: Ilius and lumbar spinous processes
Insertion: Thoracic and cervical vertebrae

Question 3

External oblique

Answer 3

Action: Laterally flexes and rotates vertebral column. Bilaterally compresses abdominal wall

Origin: Ribs
Insertion: Ilius

Question 4

Rectus abdominis

Answer 4

Action: Flexes vertebral column and compresses abdominal wall

Origin: Pubis
Insertion: Xiphoid process of sternum and ribs