Download zygomatic bone

Articulation
• Articulation is the movement and placement of
the articulators to shape the vocal tract.
• The buzz produced by the vibrating vocal folds
is shaped into sounds or phonemes by the
articulatory system.
• As the laryngeal or glottal vibrations travel
superiorly through the vocal tract, they are
selectively attenuated so that certain
frequencies are transmitted more strongly
than others.
– Vocal tract = pharyngeal, nasal, & oral
cavities
• Articulation sites
Bilabials =
Labiodental +
Interdentals =
Lingual alveolars =
Palatals =
Velars =
Glottal =
• Source-filter theory = explains how glottal
tone is changed into speech sounds by the vocal
tract.
– The three cavities of the vocal tract can
change shapes due to moveable articulators
– The changes in shape cause resonant
frequencies to change.
• Resonant frequency = frequency that
cavity responds to most effectively
• Example: bottle with water*
• /s/ vs /sh/ Which has a lower
frequency?
• http://www.uiowa.edu/~acadtech/phonetics/#
• See articulation anatomy on the website above.
– With consonants, sources of sound can
include turbulence of frication with or
without voicing.
– Articulators are movable or not movable
• THE ARTICULATORS
• First we will examine the framework and
muscles, then relate structures to speech
production
• SKULL = supportive framework
– Composed of 22 bones.
– All except mandible are rigidly joined together
by sutures*
– Main sutures = coronal. sagittal, lambdoidal, and
squamosal suture
• Coronal = divides skull into front and back;
between frontal and parietal bones
• Sagittal = divides skull in L and R; between the two
parietal bones
• Lambdoidal = between parietal and occipital bones;
shaped like Greek letter
• Squamosal = between parietal and temporal bones
– Identify these sutures on the next two
slides
• Sutures = joints that are immoveable
• Lambdoidal = occipital
• Lateral view
What sutures are shown?
1.
Mandible
•
Mental symphysis = two parts fused here
•
Mental protuberance = midline; creates
triangular eminence (prominence)
•
Mental foramen
•
Corpus
•
Angle
•
Ramus
• Coronoid process
• Condylar process (articulates with
temporal bone, allowing rotation of
mandible)
•
Mandibular foramen (inner aspect)
(branch of Trigeminal, CV, goes through
here to provide sensory innervation to
teeth and gums)
•
Mylohyoid line (mylohyoid muscle inserts
here)
•
Mandibular hypoplasia and
micrognathia
• May cause some instances of cleft
palate
• Can be corrected surgically or with
distraction osteogenesis
Hemifacial microsomia
Hemifacial Microsomia
Characteristics
• Hemi = half, although present in
bilateral condition in up to 15%-16% of
cases
• Unilateral or bilateral underdev of
mandible
• Unilateral or bilateral
underdev/malformations of ear
(microtia, ear tags, etc)
• Unilateral or bilateral reduction in size
and flattening of maxilla
• Narrowing of the opening of the eye
Causes: thought caused by hemorrhage
from artery that produces hematoma in
area of branchial arches (head, neck
area dev from branchial arches).
Occurs during first 6-8 weeks of
pregnancy.
• Inheritance: sporadic; reports of
familial cases. May be auto dominant,
auto recessive, or multifactorial.
Pierre Robin sequence shown below. Etiology is
unknown. It can occur as one sign of some
syndromes. Note the micrognathia of the infant.
Young child has distractor in place and trach.
2.
Maxillae: two bones join to make up upper
jaw (anterior ¾ of hard palate)
–
–
–
–
–
–
–
–
–
–
Frontal process (superior-most part of
maxillae); maxilla articulates with frontal
bone
Zygomatic arch = articulates with
zygomatic bone
Infraorbital foramen (passageway for
branch of CV (Trigeminal) that supplies
sensation to lower eyelid, upper lip, and
nasal alae)
Anterior nasal spine
Alveolar process =
Maxillary sinuses (see next slide)
Palatine process = articulates with
palatine bone
Incisive foramen = nerve passageway for
nasal mucosa
Premaxillary suture = line that divides
primary palate OR premaxilla from
secondary palate.
• Premaxilla can be clefted as either
unilateral or bilateral
Intermaxillary suture = cleft of hard
palate follows this suture
3.
•
Nasal bones: small oblong bones, form
bridge of nose
Articulate with frontal bone (above),
perpendicular plate of ethmoid, and nasal
bone from opposite side, and maxilla.
4.
Palatine bones: shaped like letter "L“
–
Contribute to formation of 3 cavities:
floor and lateral wall of nasal cavity, roof
of mouth (posterior 1/4), floor of orbital
cavity
–
–
–
Posterior nasal spine
Horizontal plate = posterior ¼ of hard palate
Orbital process = sm portion of floor of
orbital cavity
5.
Lacrimal bones
–
–
smallest facial bones
form medial walls of orbital cavities
6.
Inferior nasal conchae
–
–
–
–
Inferior nasal conchae (scroll-like)
(inferior turbinates): forms part of
lateral nasal wall
Note: medial and superior nasal conchae
are processes of the ethmoid bone (to be
discussed later)
Mucosal lining overlying the nasal conchae
is thickest of the nose and is richly
invested with vascular supply.
Air is warmed and humidified as passes
through the conchae
7.
Vomer
•
•
Inferior and posterior half of bony septum
Name means plowshare
8.
Zygomatic bones OR Malar* bones
–
–
–
–
forms zygomatic arch (OR cheekbones)
with maxilla and temporal bones
Makes up lateral orbit
Processes names for bones with which
zygomatic bones articulates
Imp. muscles of articulation and
mastication attach to the zygomatic bone.
Treacher Collins syndrome: one feature is hypoplasia of
the malar (zygomatic bones). Rib cartilages may be
used to restructure the cheekbone. Single gene
syndrome that is inherited in a dominant pattern.
Father, daughter,
granddaughter; all have TC
•
http://www.a3bs.com/3d/A291/index.cfm
– Outstanding animations of all facial and cranial bones!
• http://www.gwc.maricopa.edu/class/bio201/sku
ll/skulltt.htm
– Allows you to click on various bones of the skull
and see the name and exact dimensions/location
of the bone.
• http://www.meddean.luc.edu/lumen/meded/gro
ssanatomy/dissector/index.html
– Select Head and Neck
– Select Muscles
– Select muscles discussed in this section
– Select Exam
– Select Skull Practical
– See if you can name the bones and parts
discussed in the notes.
• http://www.innerbody.com/htm/body.html
– Select skeletal system
• Skull views
– Select muscular system
• Select a facial muscle and see where it’s located
and read the function.
• http://www.innerbody.com/anim/nasal.html
• Bones of Cranium
•
•
•
•
•
•
Ethmoid
Frontal
Parietal (2)
Occipital
Temporal (2)
Sphenoid
1.
Ethmoid bone
•
Extremely complex (2nd only to sphenoid),
yet delicate (light weight); filled with air
spaces
Projects down from between the orbital
plates, dividing nasal cavities (along with
vomer bone)
Contributes of walls of orbital and nasal
cavities
•
•
http://www.theodora.com/anatomy/
•
http://anatomy.med.umich.edu/nervous_system/ear.html
–
–
–
Scroll down and click on skull structures
Shows CT of head; ethmoid and maxillary sinuses displayed
Can you name all of the bones shown below?
• Ethmoid: parts
– A. Cribriform plate = separates cranial
from nasal cavities
• Forms roof of nasal cavities
• Houses olfactory bulbs
• Pix below from csuchico website
– B. Crista galli = projects upward from
cribiform plate
• Serves as attachment for falx cerebri
– C. Middle and superior nasal conchae
– D. Perpendicular plate = projects inferiorly
• Superior bony part of nasal septum
– E. Orbital plate
Arrow indicates falx cerebri
• Where is crista galli?
2.
Frontal bone
•
Anterior cranial case, forehead, supraorbital region
(roof of orbital cavity)
In infancy, frontal bone was divided in two, with the
metopic suture separating the halves
KNOW this figure and the bones shown. From:
www.upstate.edu/cdb/grossanat/hnskullant.shtml
•
•
Frontal bone: Parts
– A. Superciliary arches =
– B. Glabella = prominence above nasal notch
– C. Frontal sinuses = located behind
superciliary arches
glabella
Can you locate the superciliary arches?
•
•
•
•
3. Parietal bones
Roof of cranium
Joined by sagittal suture
Separated from occipital bone by lambdoidal
suture
• Laterally, separated from the temporal bones
by the squamosal suture
• Superior and inferior temporal lines
• Pix from
www.upstate.edu/cdb/grossanat/hnskullant.s
html
• 4.
Occipital bone
• Lower and posterior portion of cranium
• Parts:
– A. Foramen magnum = medulla oblongata
passes through (from superior to inferior)
and becomes spinal cord
– B. Occipital protuberance = external
midline projection that is visible from
behind
– C. Cerebellar fossa (internal structure);
houses cerebellum
– D. Condyles = articulate with C1
Occipital
protuberance
• 5.
Temporal bones
• Lateral base and sides of cranium
• Divided into 4 parts
• Parts:
– A. Squamous:
• zygomatic process (forms part of
zygomatic arch
• attachment for bulk of masseter muscle
(muscle of mastication)
• External auditory meatus
• Mandibular fossa = forms TMJ with
condyle of mandible
– B. Mastoid
• Attachment for neck muscles
– C. Petrous = houses organs of hearing and
equilibrium (see internal pix, next slide)
– D. Styloid process (freq. missing in
specimens); origin for several muscles
• 6. Sphenoid bone
• Most complex of cranial bones
• Located posterior to ethmoid and anterior to
foramen magnum
• Likened to bar or butterfly
• Sphenoid: Parts
– A. Body or corpus (view superiorly)
• Sella turcica (hypophyseal fossa)=
houses pituitary gland
• Optic nerve passes through body
• Sphenoid sinuses located in body (air
filled spaces)
• Optic chiasm (directly anterior to
hypophyseal fossa) located in chiasmatic
groove.
– B. Lesser and greater wings; comprise part
of the orbital cavity
– C. Lateral and medial pterygoid plates
• Hamulus projects from each medial
pterygoid plate; tendon of tensor veli
palatini muscle rounds the hamulus as
tensor changes direction from superior
to horizontal orientation.
• http://www.a3bs.com/3d/A291/index.cfm
Medial pterygoid plate
•Dentition
• Function:
– Mastication
– Surfaces for articulation of speech sounds
• Four types of teeth/number in permanent
dental arch (mandible or maxilla)
– Incisors (cutting) (4)
– Cuspids/Canine (tearing) (2)
– Bicuspids (two cusps) (4)
– Molars (grinders) (6); 3rd molars sometimes
called wisdom teeth
– Total # of permanent teeth:
– Total # of deciduous teeth:
– Teeth in the maxilla are larger than those
in the mandible.
– Maxillary teeth overlap mandibular teeth
• Surface terms
– Midline (between central incisors
– Buccal (toward cheek)
– Distal (away from central incisors)
– Lingual (towards tongue)
– Medial (towards midline)
• Development
– Deciduous teeth:
• Lose incisors between 6 & 9
• Lose cuspids and molars 9-12
• Lose 2nd molars @ 10
• Teeth not in deciduous arch:
• Teeth Anomalies (a few examples)
– Supernumerary teeth
– Microdontia (teeth smaller than normal)
• Occlusion = alignment of maxillary teeth with
mandibular teeth.
– Types of occlusion-determined by
alignment of 1st molar in each arch.
• Class I occlusion: (neutroclusion) cusp
of the maxillary first molar occludes in
the buccal groove of the mandibular
molar.
– Book definition = 1st mandibular molar is
½ tooth advanced as compared to
maxillary 1st molar.
– Max incisors overlap mandibular by a few
millimeters
– Considered to be the normal relationship
between molars in the arches.
• Class II malocclusion: the 1st mandibular
molar is retracted at least one tooth
from the 1st maxillary molar
• Class III malocclusion: 1st mandibular
molar is advanced farther than one
tooth from 1st mandibular molar.
• Class I malocclusion:
• Other dental anomalies
– Overbite—vertical dimension
– Overjet—horizontal dimension; refers to
front teeth only
– Diastema
– Crossbite
– Closed bite
– Supraversion
– Infraversion
– Speech effects
Name the occlusion
A
C
B
D
E
• Cavities of Vocal Tract
– Oral, pharyngeal, nasal
– Oral tract/cavity
Anterior faucial pillar
Posterior faucial pillar
Lingual frenum
Ankyloglossia
In little children, the superior labial frenum is
often attached between the two central
teeth. In most cases, this attachment migrates
away from the teeth as the child approaches the
age of 8 or 9.
– Pharyngeal cavity
» Nasopharynx—space above soft
palate (bounded anteriorly by
nasal choanae) (choana = funnel)
» Association between removal of
adenoids and VPI
» Oropharynx (bounded anteriorly
by fauces/faucial pillars;
superiorly by
;
inferiorly by hyoid bone
» Laryngopharynx (bounded
inferiorly by esophagus
Pharyngeal tonsil
or adenoids
Eustachian
tube orifice
laryngopharynx
• Facial muscles
• Facial landmarks:
– Cupids bow
– Vermilion
– Lips: many facial muscles insert into lips
• Important for articulation of bilabials and
labiodentals
philtrum
Bifid uvula
•
Orbicularis oris: principle muscle acting on
lips
–
no origin or insertion
–
Main function is closing mouth, puckering
lips
–
Many muscles insert into the orbicularis
oris
• 2 transverse muscles
• Buccinator muscle (transverse) (deep m)
(bugler’s muscle)
– Principle muscle of cheek
– Action: compresses cheek, draws corner of
mouth laterally
– Masticatory func: keeps foods from
slipping out between teeth while tongue
works to keep food between grinding
surfaces.
– #37
• Risorius muscle (transverse) (L risus =
laughter)
– Runs parallel and superior to buccinator
– Action: retracts angle of mouth;
– Action: when contracting in conjunction with
zygomatic muscle results in smile
– #38
• Angular muscles
• Zygomatic Minor:
– Origin = malar surface of zygomatic bone-courses downward and medially
– Function: elevation of upper lip
• Zygomatic Major:
– Origin = lateral to zygomatic minor on malar
surface of zygomatic bone--inserts into
corner of mouth
– ACTION = draws corner of mouth up and
backward = grinning, smiling
Zygomatic minor
• Levator Labii Superior:
– Origin = lower border of orbit mainly (some
fibers from frontal process of maxilla & some
from zygomatic bone). Inserts near median of
upper lip.
– ACTION = elevator of upper lip & may evert it
slightly
L labii superior
Zygomatic minor
risorius
Zygomatic major
• Levator Labaii Superior Alaeque Nasi M.:
– origin = frontal process of maxilla &
infraorbital margin; courses downward &
slightly laterally; 2 insertions = lateral
portion of nose & o. oris
– ACTION = elevator of upper lip and dilator
of nostrils
L l superior
alaque nasi m
• Depressor Labii Inferior:
– origin = oblique line of mandible, inserts into
lower lip lateral to midline.
– ACTION = depresses lower lip
D labii inferior
• Vertical muscles
• Mentalis:
– origin = mental turberosity; inserts = some
fibers insert into contralateral Mentalis,
some into skin of chin, some into o. oris.
– ACTION = wrinkles chin, everts lower lip
mentalis
• Depressor Anguli Oris =
– superficial;
– origin = oblique line; insertion = corner of
mouth;
– ACTION = depressor of angle of mouth,
compresses lips by pulling upper lip
downward onto lower lip
D anguli oris
• Levator Anguli Oris =
– deep m.;
– origin = canine fossa (pit or hollow just
lateral to canine eminence); insertion =
corner of mouth at upper lip;
– ACTION = draws corners of mouth up and
medially.
L anguli oris
FYI
Anatomically, dimples may be caused by variations
in the structure of the facial muscle known as
zygomaticus major. Specifically, the presence of a
double or bifid zygomaticus major muscle may
explain the formation of cheek dimples.[2] This
bifid variation of the muscle originates as a single
structure from the zygomatic bone. As it travels
anteriorly, it then divides with a superior bundle
that inserts in the typical position above the
corner of the mouth. An inferior bundle inserts
below the corner of the mouth.
•
•
http://www.ivy-rose.co.uk/Topics/FacialMuscles.htm
The above cited website provides a good test of
your knowledge about facial muscles.
• Tongue
• Tongue = biol. func. = taste (complemented by
smell), mastication (moves food between teeth
for grinding, forms bolus, and propels bolus
into pharynx), & deglutition (swallowing)
• Most imp and most active articulator
• Capable of rapid and subtle movements due to
high innervation and complex arrangement of
muscle fibers.
• All muscles innervated by C XII; hypoglossal
cranial nerve
• Regions of tongue:
– tip—nearest central incisors
– Blade—just below alveolar ridge
– Front—below hard palate (dorsum)
– Back—below soft palate
•
•
•
•
Taste buds:
– Anterior: sweet & salty (posterior = bitter)
– Sides: sour
– Terminal sulcus
Foramen cecum = pit
Sulcus terminalis = separates anterior 2/3 from posterior 1/3
Vallate papillae: V-shaped row, anterior to foramen cecum
?
• Plane/cut shown below?
• Pix from:
•
http://www.meddean.luc.edu/lumen/meded/grossana
tomy/dissector/
Try the Exams, Skull Practical. Only focus on
structures that are named in the notes.
• Intrinsic muscles
• Overall function = shaping tongue
– Superior longitudinal
• Upper layer of tongue
• Originates near epiglottis; inserts into tongue apex
and lateral margins
• Action: elevate tip
– Inferior longitudinal
• Origin: root of tongue & corpus of hyoid; inserts
into tongue apex
• Lower tongue base; absent in medial tongue base
(genioglossus occupies medial area)
• Action: tongue turns downward
– Transverse
• Action: narrow tongue
– Vertical -- depression of tongue dorsum
• Flatten tongue
• Tongue anomalies
– Microglossia
– Macroglossia (e.g., Beckwith-Wiedemann
syndrome
– Bifid tongue
– Pseudomacroglossia (associated with
micrognathia)
•
•
1.
Extrinsic tongue muscles
Function = general movement of tongue
Genioglossus (pix www.answers.com)
•
Prime mover of tongue
•
Comprises bulk of tongue tissue
•
Strongest and largest of extrinsic
muscles
•
Flat, triangular in shape
•
Origin at symphysis; fans out; inserts into
tip and dorsum of tongue
•
Function: anterior portion retracts
tongue; posterior fibers protrude tongue;
together fibers depress tongue
2.
Hyoglossus
•
Origin: hyoid; insertion: sides of tongue
•
Function: pulls sides of tongue down;
retracts and depresses tongue; raises
hyoid
•
I’m considering the chondroglossus m.
part of the hyoglossus. Chondro m. arises
from lesser cornu
3.
Styloglossus
•
•
•
Origin: styloid process of ? ; insertion:
inferior sides of tongue
Action: draws tongue back and up
Pix: http://webpages.charter.net/reinerwt/themodel.htm
• 4. palatoglossus
– Commonly called anterior faucial pillar
– Can be considered as a muscle of tongue or
palate
– Origin: anterior surface of soft palate;
Insertion: sides of tongue
– Function: elevates back of tongue, closes
oropharyngeal isthmus and aids initiation of
swallowing ; depresses soft palate
– Motor innervation: C XI: Accessory
• Muscles of mastication
•
•
Function = elevate or depress mandible
These muscles are one of the most strongest
in the body
•
http://www.dentalwisdom.com/animationstudio/flashpla
yer28.html
–
View film on TMJ
Elevators
1. Masseter
•
Most superficial muscle of mastication
•
Origin = zygomatic arch; insertion = ramus
of mandible
•
Action = elevates mandible
2.
Temporalis muscle
•
•
•
•
•
Fan-shaped muscle
Origin = temporal fossa of temporal and
parietal bones
Insertion = coronoid process and ramus
Function = elevates mandible and draws it back
if protruded
It is considered a snapping muscle, built for
speed (tearing food)
3.
Medial (internal) Pterygoid muscle
•
Origin = pterygoid plate and fossa
(sphenoid bone)
•
Forms mandibular sling with mandible
(angle of mandible rests in the sling)
•
Function = elevates mandible
Protruder
4. Lateral (external) Pterygoid muscle
•
Origin: Has two heads (sphenoid—
pterygoid plate and greater wing);
insertion = mandible
•
Function = protrudes mandible
Depressors
5. Digastricus
•
Has anterior and posterior belly, united by
central tendon
•
•
•
Posterior belly originates from mastoid process
and inserts onto corpus of hyoid bone where it
joins with the anterior belly by means of the
central tendon.
Anterior belly originates from mandibular
symphysis, goes to central tendon,
Function
•
•
Anterior = elevates hyoid and pulls it forward;
depresses mandible when contracts in
conjunction with posterior belly
Posterior = pulls hyoid backward and upward;
depresses mandible when contracts with
anterior belly
6.
Mylohyoid
•
•
•
•
Origin = mylohyoid line
Insertion = Median raphe and hyoid
Function = depresses mandible
Forms floor of the mouth
7.
Geniohyoid
•
Origin = mental spine on inner aspect of
mental symphysis (just superior to
mylohyoid m)
•
Insertion = hyoid bone
•
Action/Function = assist in elevating
larynx or depressing mandible
8.
Platysma
•
Considered a facial muscle
(embryologically developed from same
primordia from which facial muscles
originated)
•
Covers most of the lateral and anterior
regions of neck
•
Action = mandibular depressor
•
Go to www.innerbody.com
Muscles of the Velum
•
•
•
•
•
Levator veli palatini
Musculus uvulae
Tensor veli palatini
Palatoglossus
Palatopharyngeus
• 1. levator veli palatini
– Function: elevates and retracts soft
palate or velum
– Origin = petrous portion of temporal bone
and wall of Eustachian tube.
– Courses= downward and forward
– Inserts into member from other side
– Innervation= C XI (accessory) and CX
(vagus)
• 2. Musculus uvulae
– Paired muscle (sometimes referred to as
one muscle)
– Function:
• Shortens soft palate, creating bunching
or bulk on nasal side that aids in
velopharygeal closure,
• and helps to elevate the soft palate.
– Origin: posterior nasal spines of ? and from
palatal aponeurosis.
– Courses: near midline in soft palate
Insertion: near base of uvula (midline
pendulous structure)
– Bifid uvula occurs in 1/75 people
• 3. Tensor Veli Palatini
Origin: sphenoid bone
Insertion: converges on tendon; tendon
rounds hamulus and attaches to palatine
bones and inserts into palatine aponeurosis
Function: acts on palatine aponeurosis to
produce taut palate--TVP is active during
inspiration, producing a taut palate; taut
palate is more desirable for unimpeded
airflow; A floppy palate would be more
prone to make pharyngeal wall contact, esp.
in the supine position; opens e. tube
permitting press. equalization within middle
ear cavity.
Innervation: CN V, the trigeminal nerve
• 4.
Palatoglossus (anterior faucial pillars)
–
Origin: anterior surface of soft palate--in
most individuals, attachments nearer uvula
than rim of hard palate (suggests may have
very limited ability to elevate tongue)
– Insertion: dorsum and side of tongue
– Function: velar lowering, i.e. drawing
velum anteriorly; tongue upward and
posterior movement, and constriction of
anterior faucial pillars (helps propel food
bolus); speech function remains unresolved;
may be important in terms of opposing
gravity (i.e. sleeping in the supine position).
The elasticity of the palatoglossus would
tend to keep the airway patent without m.
contraction. Changes in elastic fibers occur
with age, they get more lax. The result may
be more mouth breathing and snoring in
older individuals.
• 5. Palatopharyngeus (posterior faucial
pillars)
– Origin: Fan-shaped in soft palate
– Insertion: Tapers to termination in
posterior border of thyroid cartilage of
larynx and into pharynx
– Function: Active during orally produced,
velum elevated speech sounds (although
anatomically situated to lower the velum)-may function to make subtle adjustments of
velar height when velum in elevated state;
lowers the velum vertically; decrease
distance between faucial pillars (action
vigorous during swallowing and gagging).
– Innervation: CN XI and X