HEAD/NECK: Throat/ Pharynx
‹ Overview:
Sagittal view of
nose/mouth/throat
‹ Nasal Cavity and Breathing
‹ Mouth and Chewing
‹ Throat and Swallowing
‹ Larynx and Singing
Sagittal Section Head
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Cranial cavity
Brain/Spinal cord
Vertebral bodies
Epaxial muscles
Hard/soft palate
Oral cavity
Esophagus
Trachea
Epiglottis
Nasopharynx
OroLaringo-
Nose/Nasal Cavity and Breathing
Function:
‹ Inlet for air to
lung
‹ Warm/filter air
(mucous membranes on
ethmoid conchae)
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Smell
(nerve endings on nasal
membranes)
M&M, Fig. 21.1
Conchae of Ethmod Bone
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M&M, Fig. 7.10
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Scroll-like bones
Covered in mucous membrane f
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Smell
Filter air
Warm air
Sinuses
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Maxillary
Ethmoid
Frontal
Sphenoid
M&M, Fig. 7.11
All connected to
nasal cavity
All lined with
mucous
membranes
Cold/allergies—fill
with mucous=sinus
headache
Mouth/Oral Cavity and Chewing
FUNCTION
• Bite and chew food
• Form words
• Taste
• Kiss
Lined by thick
stratified squamous
epithelium (almost
no keratin)
COMPONENTS
‹ Lips
‹ Cheeks
‹ Palate
‹ Jaws and teeth
‹ Salivary glands
Vestibule—in front of teeth
Oral cavity proper—behind teeth
FUNCTION
‹ Close mouth
‹ Keep food in
‹ Make speech sounds
‹ Tactile
Lips
STRUCTURE
‹ Core of sphinchter-shape
skeletal muscle (orbicularis
oris)
‹ “Red margin” transition from
keratinized skin to oral
mucosa
– Red because clear color lets
underlying vessels show through
– No sweat or sebaceous glands,
thus needs to be wet (or lip
balm)
M&M, Fig. 11.6
FUNCTION
‹ Form side of moth
Cheeks
STRUCTURE
‹ Buccinator muscle—
instrumental in
swallowing, connects
back to pharyngeal
constrictors
M&M, Fig. 11.6
Palate
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Hard palate anterior
– Maxilla
– Palatine
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Soft palate is
posterior extension,
soft tissue
Palatoglossal arch
(palate to tongue)
Palatopharyngeal
arch
(palate to pharynx)
Tonsils between
arches
Uvula…???
M&M, Fig. 22.7
Jaws
FUNCTION
‹ Hold teeth
‹ Occlude in
chewing
M&M, Fig. 7.3
STRUCTURE
•Upper jaw—maxillary bone
•Lower jaw--mandible
Teeth
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Deciduous teeth—
”milk” or “baby”
teeth
Emerge 6 mos. – 2
yrs.
Replaced by
permanent teeth 612 yrs.
Wisdom teeth (3rd
Keyerupts
to healthy
molar)
17-teeth
25
and
gums: in jaw
yrs or
remains
•Flossing
•Visiting dentist
regularly (every 6
mos.) and starting at
young age (3-4 yrs.)
Structure of individual tooth—it’s alive!!
Jaw muscles
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Masseter, temporalis—
elevate mandible (“close
jaw”)
Medial pterygoid—lateral
(side-to-side) chewing
Lateral pterygoid—
translates mandible
anteriorly (part of
opening)
Digastric (not shown)—
depresses mandible
(“opens jaw”)
Chewing is circular
motion
M&M, Fig. 11.7
Tongue
FUNCTION
‹ Position food
between teeth
‹ Form words in
speech
STRUCTURE
‹ Intrinsic muscles
(allow for shape
change with fibers
in various
directions)
‹ Extrinsic muscles—
attach tongue to
skeleton
– Genioglossus
– hyoglossus
M&M, Fig. 22.7
Salivary glands
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Intrinsic—all over
mucous
membranes of
tongue, palate,
lips, lining of
cheek
Extrinsic—secrete
more saliva when
eating (or
anticipating)
– Parotid
– Submandibular
– sublingual
M&M, Fig. 22.10
Saliva
Moistens mouth
‹ Dissolves food to be tasted
‹ Wets and binds food
‹ Contains amylase to start starch
digestion (saltine to sugar experiment)
‹ Contains bicarbonate to neutralize cavitycausing acids produced by bacteria
‹ Contains anti-bacterial and anti-viral
enzymes and cyanide-like compound to
kill harmful micro-organisms
‹ Contains proteins that stimulate growth
of beneficial bacteria in the mouth
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Throat/Pharynx and Swallowing
‹ Back
of mouth to larynx
‹ Food and air mix and cross
Trache
a
gus
PHARYNX
Esopha
STRUCTURES
•Entry—pharyngeal arches
•Exit—glottis (epiglottis is lid)
•Pharyngeal constrictors
squeeze food through
•When it goes wrong—choking!!
Air
Food
Pharynx and Swallowing
Focus on muscles and arrangement of mouth
cavity, pharynx, larynx, epiglottis, trachea
Pharynx/Swallowing
in detail!!
Descent of the larynx
Larynx and Singing
FUNCTION
‹ Channel air out of trachea
‹ Vibrate to produce sound for
speech/song
STRUCTURES
‹ External skeleton or frame
(cartilage)
‹ Internal vocal cords and associated
muscles
Skeleton of larynx
M&M, Fig. 21.5
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Cricothyroid ligament is usual site of emergency
tracheotomy (feel on self—SURFACE ANATOMY)
Vocal cords
M&M, Fig. 21.6
COMING SOON!!
Head/Neck III: Special
Senses
Head/Neck IV: Cranial
Nerves