Muscles of Articulation Facial Expression Flashcards
4 Groups of Articulatory Muscles Are?
- Muscles of the tongue
- Muscles of the velopharyngeal Mechanism
- Muscles of mastication
- Muscles of facial expression
Muscles of Facial expression
- Orbicularis Oris
- Transverse Muscles
A. Buccinator (2)
B. Risorius (2)
- Angular Muscles:
A. Zygomatic Major (2)
B. Levator Labii Superior (2)
C. Depressor Labii Inferior (2)
- Vertical Muscles:
A. Levator Anguli Oris (2)
B. Depressor Anguli Oris (2)
C. Mentalis
B. Other
Frontalis (2)
Orbicularis Oculi (2)
Nasals (2)
Platysma (1)
Orbicularis Oris [OO]
Primary muscle of the lips
It is an oval ring of muscles located within the lips
It completely encircles the oral opening
It is comprised of short fibers that overlap in a circular fashion
SPHINCTER MUSCLE
Function:
A. when active, it closes the mouth + puckers the lips
B. When activated with other muscles, it will close the mouth in a straight line
Transverse Muscle: Buccinator
BUCCINATOR is the PRIMARY MUSCLE OF THE CHEEK
it is the DEEPEST OF THE FACIAL MUSCLES
It ORIGINATES on the pterygomandibular ligament (hamulus to the last molar)
It courses horizontally + anteriorly
Its fibers decussate (cross) at the corners of the oral cavity to insert into Orbicularis Oris
FUNCTION: draws the corners of the mouth laterally
Transverse Muscle: Risorius
ORIGIN: Fascia covering master
COURSE: Horizontally + anteriorly. Parallel + superficial to buccinator
INSERT: Skin + mucosa at corners of oral cavity [Orbicularis Oris]
FUNCTION: Assists in drawing corners of mouth laterally
Angular Muscle: Zygomatic Major
ORIGIN: Surface of zygomatic bone
COURSE: Inferiorly + medially
INSERT: OO and skin at corner of oral cavity
FUNCTION: Draws corners of mouth superiorly + laterally to form a broad smile
Angular Muscle: Levator Labii Superior
ORIGIN: Lower margin of the orbit of the eye
COURSE: inferiorly
INSERT: upper lip, lateral to levator anguli oris
FUNCTION: Elevates the upper lip
Angular Muscle: Depressor Labii Inferior
Origin: Mandible, just lateral to midline
Course: superiorly and medially
Insert: lower lip
Function: Draws lower lip inferiorly and laterally
Vertical Muscle: Levator Anguli Oris
Origin: lateral to the nasal ala
Course: inferiorly
Insert: Into OO with some fibers decussating to the lower lip
Function: Draws corners of the oral cavity superiorly + aids in closing the lower lip
Vertical: depressor Angle Oris
Origin: mandible, slightly lateral to midline
Course: superior
Insertion: OO with some fibers crossing to upper lip
Function: Depresses the angle of the lip and draw the upper lip down
Vertical Muscle: Mentalis
Origin: mental tuberosity of the mandible
Course: superior
Insertion: some fibers insert into the chin, some into OO
Function: Contraction will evert the lower lip, wrinkle the chin, and stiffen the lower lip so that the mouth can be closed in a line
Other: Frontalis
A thin, quadrilateral muscle
Origin: Galea Aponeurotica (dense layer of fibrous tissue that covers the upper part of the cranium)
C: inferiorly
I: Subcutaneous tissue of the eyebrows
F: elevates eyebrows in glancing upward. Expressions of surprise/fright. Wrinkles skin of forehead.
Other: Orbicularis Oculi
Ring-like band of muscle that surrounds the eye. It is a sphincter muscle
O: frontal + maxillary bone
C: completely encircles the eyes
I: Skin of the eyelids (upper + lower)
F: Blinking, squinting, forceful closure of the eyes
Other: Nasalis
A sphincter-like muscle. also classified as an accessory muscle of respiration that can be recruited during times of respiratory distress
O: Frontal process of maxilla, just superior to the upper incisors
C: medially and transverse
I: dorsal of nose
F: flares the nares
Other: Platysma
Wide sheet of skeletal muscle
o: Deep fascia and skin on the lower neck and upper chest (specifically, pectorals major and deltoid muscles)
C: superiorly/medially along the side of the neck
I: inferior border of the mandible; skin of the face just inferior to the oral cavity
F: Draws lower lip and angle of mouth downward in expressions of horror or surprise. May assist in opening the mouth very widely
