Exam 1, DLA 1210

1. Muscles of the Head
and Neck
Part II
FACIAL EXPRESSION, NECK, SOFT PALATE, PHARYNX

2. Muscles of Facial Expression
Contraction of the muscles of facial
expression results in variety of facial
expressions
Facial nerve (VII) provides innervation
These muscles are symmetric, and work in
groups

3. Muscles of Facial Expression
Muscles of the scalp, or occipitofrontalis (epicranius)
have two groups
Frontalis
Occipitalis
This muscle pulls the scalp forward and backward and
raises the eyebrows.

4. Muscles of Facial Expression
Muscles of the ears
There are three groups
Anterior auricular, posterior auricular, and
superior auricular
They are respectively located in front of,
behind and above the ear.
These muscles may draw the ear
forward and backward, or elevate the
ear.
Which one has which function?

5. Muscles of Facial Expression
Orbicularis Oculi
This muscle encircles the eye.
It is divided into orbital and palpebral
(eyelid) sections, and its function is to close
the eyes.

6. Muscles of Facial Expression
Procerus
This muscle runes from the
bridge of the nose to the
eyebrow.
It pulls the eyebrows downward.

7. Muscles of Facial Expression
Corrugator
This muscle runs along
the eyebrow and inserts
on the medial end of the
eyebrow.
It pulls the eyebrow down
and in.

8. Muscles of Facial Expression
Muscles of the Nose include:
Nasalis (divided into two parts)
Compressor nares
closes nostrils
Dilator nares
Flares nostrils

9. Muscles of the Mouth
MUSCLES OF FACIAL EXPRESSION

10. Muscles of the Mouth
Orbicularis Oris
No skeletal attachment
It encircles the mouth and composes
the lips
Its function is to close the lips or
protrude them.
Its fibers interface with other perioral
muscles.

11. Muscles of the Mouth
Levator Labii superioris alaeque nasi
This tiny muscle inserts on the ala of the
nose and runs to the upper lip.
It raises the upper lip and ala of the nose,
producing a sneer.

12. Muscles of the Mouth
 Levator Labii Superioris or Quadratus Labii
Superioris
This muscle runs above the mouth and has the
following three heads:
Angular: near the nose
Infraorbital: lower edge of the orbit
Zygomatic: zygomatic bone
All three heads insert onto the upper lip and
help elevate the upper lip.

13. Muscles of the Mouth
Zygomatic
The origin of this muscle is the
zygomatic bone, and it inserts into the
corner of the mouth or the melodious,
an area of intertwining muscles.
It elevates the angle of the mouth up
and laterally, producing a smile.
It may be divided into zygomatic major
and minor muscles.

14. Muscles of the Mouth
Levator Anguli Oris or Caninus
The origin of this muscle is the
canine fossa, a depression near the
canine roots below the infraorbital
foramen.
It inserts into the modiolus and aids
in elevating the corner of the mouth,
producing a smile.

15. Muscles of the Mouth
 Buccinator
 This muscle forms the cheek.
 It originates from the alveolar process of the
mandible, the maxilla, and the Pterygomandibular
raphe (a fibrous band that runs from the pterygoid
hamulus to the Mylohyoid line.
 It blends with the orbicularis oris at the modiolus.
 The buccinator holds the cheek against the teeth
and keeps food on the occlusal surfaces during
mastication.
 because of this function, it is considered an accessory
muscle to the muscles of mastication.

16. Muscles of the Mouth
Risorius
This muscle originates on the
anterior border of the
masseter muscle and inserts
into the modiolus
It pulls the angle of the mouth
laterally and produces a wide
smile.

17. Muscles of the Mouth
Depressor Anguli Oris or
Triangularis
This muscle arises from the
external oblique line of the
mandible and inserts into the
modiolus.
It pulls the corner of the mouth
downward and inward, producing
a frown.

18. Muscles of the Mouth
Depressor Labii Inferioris or
Quadratus Labii Inferioris
This muscle also arises from the
external oblique line; however, it inserts
into the skin of the lower lip.
Its function is to pull the lip down and
laterally, showing the mandibular
anterior teeth.

19. Muscles of the Mouth
 Mentalis
This is the only muscle whose fibers run
away from the lips
Its origin is a fossa or depression beneath
the mandibular anterior teeth, and inserts
into the skin of the chin.
It can raise the skin of the chin and
protrude the lower lip.
It often interferes with treatment of
mandibular anterior labial surfaces when
contracted.

20. Muscles of the Neck

21. Muscles of the Neck
 Platysma is a thin sheet just below neck
skin
Origin is clavicle and shoulder; it travels
upward to insert into the lower border
of the mandible as well as on the skin
and muscle of the lower face and mouth
Muscle contraction wrinkles the skin of
the chin and neck, and draws the outer
part of the lower lip down and back,
producing a grimace
Innervated by the facial nerve (VII)

22. Muscles of the Neck
Trapezius
Large muscle covering back of
the neck, shoulder and clavicle
Originates from the external
occipital protuberance and
inserts into the clavicle and
shoulder.
Produces a shoulder shrug
Innervated by the spinal
accessory nerve (XI)

23. Muscles of the Neck
 Sternocleidomastoid
Arises by two heads
Top of the sternum and clavicle
Two heads blend together and insert
on the mastoid process and superior
nuchal line of the occipital bone
Turns the chin up and to the opposite
side when the head is turned laterally.
Innervated by spinal accessory nerve
(XI)

24. Muscles of the Soft Palate

25. Muscles of the Soft Palate
These muscles raise soft palate
during deglutition (swallowing)

26. Muscles of the Soft Palate
 Palatoglossal or Palatoglossus
 Forms the anterior tonsillar arch (in front
of the tonsils)
 Its origin is the underside of the soft
palate, and its insertion is the posterior
side of the tongue.
 Its contraction pulls the side of the tongue
up and back, and the soft palate down.
 It also constricts the pillars.
 It is innervated by the pharyngeal plexus (a
group of branches from the
glossopharyngeal (IX), vagus (X) and spinal
accessory (XI) nerves.

27. Muscles of the Soft Palate
 Palatopharyngeal or
Palatopharyngeus
This muscle forms the posterior
tonsillar pillar
Contraction of this muscle causes
the pharynx to elevate
It is innervated by the pharyngeal
plexus.

28. Muscles of the Soft Palate
Uvula
The small mass of tissue
hanging from the soft palate
Upon contraction, the uvula will
shorten.
Innervated by the pharyngeal
plexus

29. Muscles of the Soft Palate
Levator Veli Palatini
This muscle originates from the
petrous portion of the temporal
bone, and inserts in the soft
palate.
Pulls the soft palate up and back
It is innervated by the pharyngeal
plexus

30. Muscles of the Soft Palate
 Tensor Veli Palatini
Arises from the medial pterygoid place
and auditory tube
It turns upward and curves around the
pterygoid hamulus, and then inserts into
the soft palate.
It tenses (hence the name) the soft
palate by pulling on the lateral sides.
It is innervated by the mandibular
branch of the trigeminal nerve (V₃)

31. Muscles of the Soft Palate

32. Muscles of the Pharynx
 Pharynx is a muscular tube made of 3 constrictors and 3 smaller
muscles
 All function in swallowing and are innervated by pharyngeal plexus
 Superior Constrictor
 Middle Constrictor
 Inferior Constrictor
 Palatopharyngeal

33. Muscles of the Pharynx
Superior Constrictor
The origin is the pterygoid hamulus, medial
pterygoid plate, Pterygomandibular raphe, and the
Mylohyoid line
All three constrictors insert and unite on the
median raphe

34. Muscles of the Pharynx
Middle Constrictor
Origins of this muscle are greater and lessor horns
of the hyoid bone and the stylohyoid ligament
It unites with the superior constrictor at the median
raphe

35. Muscles of the Pharynx
Inferior Constrictor
Originates from the thyroid cartilage of the
larynx
Its fibers join at the median raphe
Fibers of all three constrictors overlap each
other.

37. Muscles of the Pharynx
 Palatopharyngeal
 Forms the posterior tonsillar pillar
 Previously, this muscle was discussed as a muscle of the soft palate.
 Its function is to elevate the pharynx, so it is also listed here under the muscles
of the pharynx….

38. Muscles of the Pharynx
 Salpingopharyngeal
Origin is the auditory tube
Its fibers blend with the Palatopharyngeal muscle
It helps elevate the pharynx, and is innervated by the pharyngeal
plexus
 Stylopharyngeal
Arises from the styloid process and inserts on the thyroid cartilage
It helps elevate and dilate the pharynx
Innervated by the glossopharyngeal (IX)

39. Deglutition
Deglution is divided into three stages
Oral when food is chewed
Pharyngeal propels food to the esophagus
Esophageal propels food to the stomach

40. Deglutition
 Oral stage
1. The bolus (ball of chewed food mixed with saliva) is centered on the tongue
2. The tongue is then raised up and back and a seal is made between the hard palate and the
tongue.
3. The sides of the tongue seal against the teeth and the mucosa of the hard palate.
4. The bolus is moved backward by the intrinsic and extrinsic muscles of the tongue, as well as
by the suprahyoid muscles.
5. The muscles of mastication hold the teeth together
6. The bolus is now positioned onto the posterior tongue.
7. The upward and backward movement of the tongue causes the muscles of the soft palate to
elevate the soft palate

41. Deglutition
 Pharyngeal stage
1. The fauces are narrowed by the palatoglossal muscle.
2. The soft palate contacts the posterior pharyngeal wall
3. The Stylopharyngeal and Salpingopharyngeal muscles elevate and dilate the
pharynx to make room for the bolus that has just entered the pharynx.
4. The superior, middle, and inferior constrictors squeeze the pharynx,
propelling the bolus into the lower end of the pharynx.
5. The thyroid cartilage of the larynx is raised and brought forward by the
thyrohyoid muscle and other muscles.
6. The epiglottis protects the larynx from the bolus
7. The food is propelled into the upper part of the esophagus.

42. Deglutition
 Esophageal stage
The bolus is propelled by peristaltic contractions
into the stomach
https://youtu.be/xFhyyBXkaNM

43. Muscles of the Pharynx

44. Summary
Muscles of the head and neck are divided into
eight groups
 Muscles of mastication moves the mandible
 Suprahyoid muscles moves the lower mandible and
raises the hyoid
 Infrahyoid muscles depresses the hyoid
 Muscles of the tongue positions and shapes it

45. Summary
 Muscles of facial expression control all aspects
of expression
 Muscles of the neck control movement of the
head
 Muscles of the soft palate aide palate during
swallowing
 Muscles of the pharynx control swallowing

46. Suggested Homework
 Take this interactive test of the muscles.
 https://www.purposegames.com/game/face-and-neck-muscles-quiz