Axial Muscles

Question 1

Temporalis

Answer 1

Elevation of mandible (mastication)

Question 2

Masseter

Answer 2

Elevation of the mandible (mastication)

Question 3

Orbicularis Oculi

Answer 3

Closes eye and aids in flow of tears across eye

Question 4

Orbicularis Oris

Answer 4

Closes lips and protrudes lips as in kissing

Question 5

Levator Palpebrae Superioris

Answer 5

Elevates upper eyelid and opens eye

Question 6

Platysma

Answer 6

Draws lower lip and angle of mouth downward and aids in opening mouth widely

Question 7

Zygomaticus Major

Answer 7

Elevates corner of mouth when smiling or laughing

Question 8

Zygomaticus Minor

Answer 8

Elevation of upper lip

Question 9

Sternocleidomastoid (O/I)

Answer 9

Origin is manubrium of sternum. Insertion is mastoid process of temporal bone. Unilateral action is contralateral rotation of head and bilateral action is flexion of the neck

Question 10

Scalenes

Answer 10

Unilateral action is lateral flexion of the neck and bilateral action is neck flexion, elevation of top 2 ribs, and aids in breathing

Question 11

Digastric (O/I)

Answer 11

Origin is digastric fossa of mandible (anterior belly) and mastoid process of temporal bone (posterior belly). Insertion is hyoid bone via fascial sling. Depresses mandible when hyoid is fixed and elevates hyoid when mandible is fixed

Question 12

Stylohyoid (O/I)

Answer 12

Origin is Styloid process. Insertion is hyoid bone. Elevate and retracts hyoid

Question 13

Mylohyoid (O/I)

Answer 13

Origin is inferior margin of mandible. Insertion is hyoid bone. Forms floor of mouth and elevates it in initial stage of swallowing

Question 14

Sternohyoid (O/I)

Answer 14

Origin is manubrium and medial end of clavicle. Insertion is hyoid. Depresses hyoid after it has been elevated

Question 15

Sternothyroid (O/I)

Answer 15

Origin is manubrium and costal cartilage. Insertion is thyroid cartilage. Depresses larynx after it has been elevated in swallowing and vocalization

Question 16

Omohyoid

Answer 16

Depresses hyoid after it has been elevated

Question 17

Thyrohyoid (O/I)

Answer 17

Origin is thyroid cartilage. Insertion is hyoid bone. Depresses hyoid

Question 18

External Intercostals

Answer 18

Inspiration through elevation and protraction of ribs 2-12, expanding the thoracic cavity

Question 19

Internal Intercostals

Answer 19

Expiration through depression and retraction of the ribs, compressing the thoracic cavity

Question 20

Diaphragm

Answer 20

Prime mover of inspiration, contraction compresses abdominal viscera, and aids in childbirth & expulsion of feces

Question 21

Rectus abdominis

Answer 21

Flexion of trunk, stabilizes pelvic region, compresses abdominal viscera

Question 22

External abdominal oblique

Answer 22

Support viscera, stabilizes vertebral column, maintains posture

Question 23

Internal abdominal oblique

Answer 23

Support viscera, stabilizes vertebral column, maintains posture, unilateral action is ipsilateral rotation of waist

Question 24

Transverse abdominis

Answer 24

Compresses abdominal contents

Question 25

Linea alba

Answer 25

Fibrous line that runs between xiphoid process and pubic symphysis. Insertion site for transverse abdominis

Question 26

Erector Spinae

Answer 26

Contains 3 muscles, lateral flexion and extension of vertebral column, rotation and extension of the head

Question 27

Iliocostalis

Answer 27

Unilateral action is lateral flexion of vertebral column. Extension of vertebral column and depression of ribs

Question 28

Longissimus

Answer 28

Unilateral action is lateral flexion of vertebral column and contralateral rotation of head. Bilateral action is extension of vertebral column and head

Question 29

Spinalis

Answer 29

Unilateral action is lateral flexion of vertebral column. Bilateral action is extension of vertebral column

Question 30

Semispinalis

Answer 30

Unilateral action is contralateral rotation of head. Bilateral action is extension of head and neck