CSD 155 LAB 10: Muscles of the Face

Question 1

modiolus

Answer 1

an important landmark because it serves as the point of insertion for several facial muscles, located near the corners of the mouth where several muscle fibers converge

Question 2

obicularis oris

Answer 2

• major muscle of the lips
• circular muscle surround the lips
• place of insertion for many other muscles
• function: constricts mouth orifice (closes mouth), raise lower lip, lower upper lip, pucker lips, protrudes lips
• “kissing muscle”

Question 3

buccinator

Answer 3

• major muscle of the cheeks
• pterygomandibular raphe to the upper and lower lip
• function: compress lips and cheeks against teeth and draw corners of the mouth laterally
• “fish face”

Question 4

risorius

Answer 4

• fascia covering the masseter to the angles (corners) of the mouth
• function: draws the corners of the mouth posterior and lateral
• “smiling”

Question 5

levator labii superior (LLS)

Answer 5

3 heads

• angular head (levator labii superioris alaeque nasi)
• – frontal process of the maxilla to the cartilage of nostril and obicularis oris
• infraorbital head (levator labii superioris)
• – lower margins of orbit of maxilla to orbicularis oris
• zygomatic head (zygomaticus minor)
• – zygomatic bone to orbicularis oris
  function: elevate upper lip, dilate nostril

Question 6

zygomatic major

Answer 6

• zygomatic bone to modiolus
• function: draws corners of mouth upward and laterally
• major muscle for smiling

Question 7

depressor labii inferioris (DLI)

Answer 7

• located beneath the lower lip
• oblique line of the mandible near the mental foramen to the obicularis oris at the lower lip
• function: draws lower lip inferiorly and laterally
• “frowning”

Question 8

levator anguli oris (LAO)

Answer 8

• deep to levator labii superioris
• canine fossa to modiolus
• function: draws corners of mouth and lower lip up
• “smiling”

Question 9

depressor anguli oris (DAO)

Answer 9

• oblique line of mandible to modiolus (some fivers insert into the upper lip)
• function: draws corners of mouth and lower lip down
• “frowning”

Question 10

mentalis

Answer 10

• located at the midline of the chin
• incisive fossa to the skin of the chin
• function: wrinkle skin of chin, elevate, protrude
• “pout”

Question 11

platysma

Answer 11

• located on the neck
• thin, flat sheet of muscle
• fascia in pectoral region and fascia covering the sternocleidomastoid muscle to the lower portion of the mandible, sides of chin and mouth
• function: scrunches chin to chest, draws lips lateral and inferior, may help to lower the jaw
• “eek” muscle