HEAD/NECK II: Throat/ Pharynx

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HEAD/NECK II Throat/ Pharynx

• Overview Sagittal view of nose/mouth/throat
• Nasal Cavity and Breathing
• Mouth and Chewing
• Throat and Swallowing
• Larynx and Singing

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Sagittal Section Head

• Cranial cavity
• Brain/Spinal cord
• Vertebral bodies
• Epaxial muscles
• Hard/soft palate
• Oral cavity
• Esophagus
• Trachea
• Epiglottis
• Naso-
• Oro-
• Laringo-

pharynx
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Nose/Nasal Cavity and Breathing

• Function
• Inlet for air to lung
• Warm/filter air
• (mucous membranes on ethmoid conchae)
• Smell
• (nerve endings on nasal membranes)

MM, Fig. 21.1
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Conchae of Ethmod Bone

• Scroll-like bones
• Covered in mucous membrane for
• Smell
• Filter air
• Warm air

MM, Fig. 7.10
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Sinuses

• All connected to nasal cavity
• All lined with mucous membranes
• Cold/allergiesfill with mucoussinus headache

• Maxillary
• Ethmoid
• Frontal
• Sphenoid

MM, Fig. 7.11
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Mouth/Oral Cavity and Chewing

• FUNCTION
• Bite and chew food
• Form words
• Taste
• Kiss

• COMPONENTS
• Lips
• Cheeks
• Palate
• Jaws and teeth
• Salivary glands

Lined by thick stratified squamous epithelium
(almost no keratin)
Vestibulein front of teeth Oral cavity
properbehind teeth
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Lips

• FUNCTION
• Close mouth
• Keep food in
• Make speech sounds
• Tactile
• 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)

MM, Fig. 11.6
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Cheeks

• FUNCTION
• Form side of moth
• STRUCTURE
• Buccinator muscleinstrumental in swallowing,
  connects back to pharyngeal constrictors

MM, Fig. 11.6
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Palate

• Hard palate anterior
• Maxilla
• Palatine
• Soft palate is posterior extension, soft tissue
• Palatoglossal arch
• (palate to tongue)
• Palatopharyngeal arch
• (palate to pharynx)
• Tonsils between arches
• Uvula???

MM, Fig. 22.7
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Jaws

• FUNCTION
• Hold teeth
• Occlude in chewing

MM, Fig. 7.3

• STRUCTURE
• Upper jawmaxillary bone
• Lower jaw--mandible

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Teeth

• Deciduous teethmilk or baby teeth
• Emerge 6 mos. 2 yrs.
• Replaced by permanent teeth 6-12 yrs.
• Wisdom teeth (3rd molar) erupts 17-25 yrs or
  remains in jaw

• Key to healthy teeth and gums
• Flossing
• Visiting dentist regularly (every 6 mos.) and
  starting at young age (3-4 yrs.)

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Structure of individual toothits alive!!
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Jaw muscles

• Masseter, temporaliselevate mandible (close
  jaw)
• Medial pterygoidlateral (side-to-side) chewing
• Lateral pterygoidtranslates mandible anteriorly
  (part of opening)
• Digastric (not shown)depresses mandible (opens
  jaw)
• Chewing is circular motion

MM, Fig. 11.7
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Tongue

• FUNCTION
• Position food between teeth
• Form words in speech
• STRUCTURE
• Intrinsic muscles (allow for shape change with
  fibers in various directions)
• Extrinsic musclesattach tongue to skeleton
• Genioglossus
• hyoglossus

MM, Fig. 22.7
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Salivary glands

• Intrinsicall over mucous membranes of tongue,
  palate, lips, lining of cheek
• Extrinsicsecrete more saliva when eating (or
  anticipating)
• Parotid
• Submandibular
• sublingual

MM, Fig. 22.10
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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 cavity-causing
  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

• STRUCTURES
• Entrypharyngeal arches
• Exitglottis (epiglottis is lid)
• Pharyngeal constrictors squeeze food through

• When it goes wrongchoking!!

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Pharynx and Swallowing
Focus on muscles and arrangement of mouth cavity,
pharynx, larynx, epiglottis, trachea
Pharynx/Swallowing in detail!!
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Descent of the larynx
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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

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Skeleton of larynx
MM, Fig. 21.5

• Cricothyroid ligament is usual site of emergency
  tracheotomy (feel on selfSURFACE ANATOMY)

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Vocal cords
MM, Fig. 21.6
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COMING SOON!!

• Head/Neck III Special Senses
• Head/Neck IV Cranial Nerves