Actions

Question 1

External Intercostals

Answer 1

• support intercostal spaces on inspiration and expiration
• elevate ribs on inspiration

Question 2

Internal Intercostal

Answer 2

• prevents pushing out or drawing in of intercostal spaces on inspiration or expiration
• lowers ribs in forced expiration

Question 3

Innermost intercostals

Answer 3

elevates ribs

Question 4

transversus thoracis

Answer 4

Pulls ribs 2-6 toward sternum on forced exhalation –> depression of those ribs

Question 5

External abdominal oblique

Answer 5

-compresses and supports abdominal viscera
- fixes and rotates trunk contralaterally

Question 6

Internal abdominal oblique

Answer 6

• comprises and supports abdominal viscera
• flexes and rotates trunk

Question 7

Transversus abdominis

Answer 7

compresses and supports abdominal viscera

Question 8

rectus abdominis

Answer 8

• flexes trunk
• compresses abdominal viscera

Question 9

quadratus lumborum

Answer 9

• extends and laterally flexes vertebral column
• flexes 12th rib during inspiration

Question 10

4 suprahyoid muscles

Answer 10

Mylohyoid
Geniohyoid
Stylohyoid
Digastric

Question 11

Mylohyoid

Answer 11

• Elevates hyoid bone, floor of mouth, and tongue during swallowing and speaking

Question 12

geniohyoid

Answer 12

• pulls hyoid bone anterosuperiorly
• shortens floor of mouth
• widens pharynx

Question 13

Stylohyoid

Answer 13

Elevates and retracts hyoid bone, elongating floor of mouth

Question 14

Digastric

Answer 14

• Works with infra hyoid muscles
• depresses mandible against resistance
• elevates and steadies hyoid bone during swallowing and speaking

Question 15

4 Infrahyoid muscles

Answer 15

• Sternohyoid
• Thyrohyoid
• Sternothyroid
• Omohyoid

Question 16

Stenohyoid

Answer 16

depresses hyoid bone after elevation during swallowing

Question 17

Omohyoid

Answer 17

Depresses, retracts, and steadies hyoid

Question 18

Sternothyroid

Answer 18

Depresses hyoid bone and larynx

Question 19

Thyrohyoid

Answer 19

depresses hyoid bone and elevates larynx

Question 20

Platysma

Answer 20

• draws corners of mouth inferiorly and widens it
• draws skin of neck superiorly when teeth are clenched

Question 21

SCM

Answer 21

Unilateral: ipsilateral lat flex and contralat rotation

Bilateral: extend neck @ AO joint; chin tuck; extend superior cervical vertebrae so child is thrust forward with head level

Question 22

Temporalis

Answer 22

Elevates mandible closing jaw
- posterior horizontal fibers retract the mandible

Question 23

Masseter

Answer 23

elevates mandible
- some contribution to mandibular protrusion

Question 24

Lateral Pterygoid

Answer 24

Bilaterally: protracts mandible and depresses chin

Unilaterally: swings jaw toward contralat side; alternate unilateral contraction produces larger chewing movements

Question 25

medial pterygoid

Answer 25

- acts synergistically with masseter to elevate mandible - contributes to protrusion - alternate unilateral activity produces smaller grinding movements

Question 26

splenius captius and cervicis

Answer 26

alone: lat flexes neck and rotates head ipsilateral together: extend head and neck

Question 27

Bilateral actions of erector spinae mm

Answer 27

- extend vertebral column and head - as back is flexed, controls movement by gradually lengthening fibers

Question 28

unilateral actions of erector spinae mm

Answer 28

laterally flex vertebral column

Question 29

semispinalis

Answer 29

- extends head, thoracic and cervical regions of vertebral column - rotates contra laterally

Question 30

Multifidus

Answer 30

unilateral contraction rotates to contralateral side - stabilizes vertebrae during local movements of vertebral column

Question 31

Rotatores

Answer 31

- may function as organs of proprioception - possibly stabilize vertebrae and assist with local extension and rotatory movements of vertebral column

Question 32

Levator costorum

Answer 32

elevate ribs, assisting with respiration - assist with lateral flexion

Question 33

anterior scalene

Answer 33

- elevate 1st rib - laterally flex and rotate neck

Question 34

middle scalene

Answer 34

- flex neck laterally - elevate first rib

Question 35

Posterior scalene

Answer 35

- flex neck laterally - elevate 2nd rib

Question 36

Rectus capitus posterior major

Answer 36

Bilat: extension Unilateral: ipsilateral rotation

Question 37

Rectus captious post min

Answer 37

extend head

Question 38

obliquus capitus inferior

Answer 38

ipsilateral rotation

Question 39

obliques captifs superior

Answer 39

bil: extension Unilateral: side bend

Question 40

Serratus post sup

Answer 40

weekly elevate ribs 2-4

Question 41

serratus post inf

Answer 41

weakly depress ribs 8-12