Chapter 10

Question 1

Epicranius

Answer 1

Bipartite muscle consisting of the frontalis and occipitalis muscles connected by a cranial aponeurosis the galea aponeurotica; pulls the scalp forward and backward

Question 2

Frontalis

Answer 2

Covers forehead and dome of skull. raises the eyebrows and wrinkles forehead skin horizontally

Question 3

Occipitalis

Answer 3

fixes aponeurosis and pulls scalp posteriorly

Question 4

Corrugator supercilii

Answer 4

draws eyebrows together and inferiorly; wrinkles skin of forehead vertically (as in frowning)

Question 5

Orbicularis oculi

Answer 5

protects eyes from intense light and injury; various parts can be activated individually; produces blinking squinting, and draws eyebrows inferiorly

Question 6

zygomaticus

Answer 6

raises lateral corners of mouth upward (smiling muscle)

Question 7

Risorius

Answer 7

Draws corner of lip laterally ;tenses lips; synergist of zygomaticus

Question 8

Levator labii superioris

Answer 8

opens lips; raises and furrows the upper lip

Question 9

Depressor labii inferioris

Answer 9

draws lower lip inferiorly (as in a pout)

Question 10

Depressor anguli oris

Answer 10

zygomaticus antagonist; draws corners of mouth downward and laterally (as in a “tragedy mask” grimace)

Question 11

Orbicularis oris

Answer 11

closes lips; purses and protrudes lips; kissing and whistling muscle

Question 12

Mentalis

Answer 12

protrudes lower lip; wrinkles chin

Question 13

Buccinator

Answer 13

draws corner of mouth laterally; compresses cheek (as in whistling and sucking); holds food between teeth during chewing; well developed in nursing infants

Question 14

Platysma

Answer 14

Helps depress mandible; pulls lower lip back and down, i.e., produces downward sag of mouth; tenses skin of neck (e.g., during shaving)

Question 15

Masseter

Answer 15

Prime mover of jaw closure; elevates mandible

Question 16

Temporalis

Answer 16

closes jaw; elevates and retracts mandible; synergist of pterygoids (see below) in side-to-side movements; maintains position of the mandible at rest

Question 17

Medial Pterygoid

Answer 17

Synergist of temporalis and massester muscles in elevation of the mandible; acts with the lateral pterygoid muscle to protrude mandible and to promote side-to-side grinding movements

Question 18

Lateral Pterygoid

Answer 18

Protrudes mandible (pulls it anteriorly); provides forward sliding and side-to-side movements of the lower teeth

Question 19

Genioglossus

Answer 19

Primarily protrudes tongue, but can depress or act in concert with other extrinsic muscles to retract tongue

Question 20

Hyoglossus

Answer 20

Depresses tongue and draws its sides downward

Question 21

Styloglossus

Answer 21

Retracts (and elevates) tongue

Question 22

Digastric

Answer 22

Acting in concert, the digastric muscles elevate hyoid bone and steady it during swallowing and speech; acting from behind they open mouth and depress mandible

Question 23

Stylohyoid

Answer 23

elevates and retracts hyoid, thereby elongating floor of mouth during swallowing

Question 24

Mylohyoid

Answer 24

Elevates hyoid bone and floor of mouth, enabling tongue to exert backward and upward pressure that forces food bolus into pharynx

Question 25

Geniohyoid

Answer 25

Pulls hyoid bone superiorly and anteriorly, shortening floor of mouth and widening pharynx for recieving food

Question 26

Sternohyoid

Answer 26

Depresses larynx and hyoid bone if mandible is fixed; may also flex skull

Question 27

Sternothryoid

Answer 27

Pulls thyroid cartilage (pulls larynx and hyoid bone) inferiorly

Question 28

Omohyoid

Answer 28

Depresses and retracts hyoid bone

Question 29

Thryohyoid

Answer 29

Depresses hyoid bone and elevates larynx if hyoid is fixed

Question 30

Pharyngeal constrictor muscles

Answer 30

Working as a group and in sequence, all constrict pharynx during swallowing, which propels a food bolus to esophagus

Question 31

Sternocleidomastoid

Answer 31

Prime mover of active head flexion

Question 32

Scalenes

Answer 32

Elevate first two ribs (aid in inspirationg) flex and rotate neck

Question 33

Splenius

Answer 33

Act as a group to extend or hyperextend head, when spelnuis muscles on one side are activated, head is rotated and bent laterally toward same side

Question 34

Iliocostalis

Answer 34

Extend vertebral column, maintain erect posture, acting on one side, bend vertebral column to same side

Question 35

Longissiumus

Answer 35

Throacis and cervicis act together to extend vertebral column and acing on one side, bend it laterally; capitis extends head and turns the face toward same side

Question 36

Spinalis

Answer 36

Extends vertebral column

Question 37

Semispinalis

Answer 37

Extends vertebral column and head and rotates them to opposite side; acts synergistically with sternocleidomastoid muscles of opposite side

Question 38

Quadratus Lumborum

Answer 38

Flexes vertebral column laterally when acting spearately; when pair acts jointly, lumbar spine is extended and 12th rib is fixed; maintains upright posture asists in forced inspiration

Question 39

4 muscles in vertebraes

Answer 39

Intertanscersarius, rotatores, multifidus, interspinales

Question 40

External intercostals

Answer 40

with first ribs fixed by scalene muscles, pull ribs toward one another to elevate rib cage; aids in inspiration; synergists of diaphragm

Question 41

Internal intercostals

Answer 41

with 12th ribs fixed by quadratus lumborum, muscles of posterior abdominal wall, and oblique muscles of the abdominal wall, they draw ribs together and depress rib cage; aid in forced expiration

Question 42

Diaphragm

Answer 42

Prime mover of inspiration; flattens on contraction, increasing vertical dimensions of thorax, when strongly contracted, dramatically increases intra-abdominal pressure

Question 43

Rectus abdominis

Answer 43

Flex and rotate lunbar region of vertebral column; fix and depress ribs, stabalize pelvis during walking, increase intra-abdominal pressure

Question 44

External Oblique

Answer 44

When pair contract simultaneously, aid rectus abdominis muscles in flexing vertebral column and in compressing abdominal wall

Question 45

Internal oblique

Answer 45

as for external oblique

Question 46

Transverses Abdominis

Answer 46

Compresses abdominal contents