Unit 2: The Airways The Upper Airways

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Unit 2 The AirwaysThe Upper Airways

• RSPT 1207
• Cardio Pulmonary Anatomy Physiology

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The Airways

• Respiratory tract combination of organs and
  tissues that have one function the transfer of
  gas to be used by the body.
• This process exposes the respiratory tract to
  many environmental extremes

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The Upper Airways

• Consists of
• The nose
• Oral cavities
• The pharynx
• The larynx

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The Upper Airways

• Function There are 4 Functions
• Direct respiratory gases to and from the lung
• Defense mechanism
• Humidify inspired air
• Heat inspired air
• Also involved with
• Speech
• Eating, drinking
• Smell

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The Nose

• Midline, external and internal structure
• Upper third is bone and covered by skin
• Lower 2/3 is cartilage

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Functions of the Nose

• Filters particles prior to entering lower airways
• Humidify and heat inspired air
• Provides a location for sensory receptors used in
  the sense of smell
• Provides resonance for speech

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Major Structures of the Nose
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Major Structures of the Nose
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Major Structures of the Nose
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Nasal Cavity

• Separated by the septum making it into a
  symmetric bilateral structure
• Anterior portion formed by the septal cartilage
• Posterior septum formed ethmoid and vomer bones

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Nasal Cavity

• External nares (nostrils) the openings of the
  nasal passageway
• Internally protected from particles by Vibrissae
  (nose hairs)
• Immediately behind vibrissae is an open chamber
  called the vestibule

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Turbinates/Conchae

• As incoming gas flow enter posterior to the
  vestibule it is separated by the turbinates or
  conchae
• By having the turbinates, surface area is
  increased for heat/moisture exchange

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Turbinates/Conchae

• Lines the nasal cavity like three walls
• Twisted to allow particles to be filtered and air
  to be heated and humidified
• Mucous membranes line turbinates, Mucous glands
  line

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Choandae

• Lumen the space (hole) in a vessel, tube, or
  intestine
• In the nasal passage this is call the Choandae
• Choanal atresia is a common birth defect found in
  infants

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Paranasal Sinuses

• Consists of the frontal, maxillary, ethmoid and
  posterior sphenoid Sinuses
• Openings are along the nasal passage
• Paired sinuses contain mucous glands and
  membranes
• Helps strengthen the skull

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Oral Cavity

• Simply known as the mouth
• Functions
• Alternate passageway for breathing
• Start of the alimentary canal
• Contains major speech structures
• Facial expressions

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Oral Cavity

• Anteriorly begins with lips and mouth
• Follows with oral vestibule and teeth and gums
• Oral cavity begins after the teeth

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The Palate

• The palate is the roof of the oral cavity
• Consists of
• Hard palate anterior 2/3 of the palate and is
  bony
• Soft palate posterior 1/3 and is made of soft
  tissue.

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The Palate

• Protects the nasal passage from food
• Aids in swallowing
• Hard palate and tongue are used in speech
• Uvula helps protect the airway from occlusion

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The Soft Palate

• Made of soft tissue
• This allows for food to be passed out of the oral
  cavity to the pharynx
• Two structures form the soft palate
• Palatoglossal arch (anterior)
• Palato-pharyngeal arch (posterior)

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The Uvula

• As the arches of the soft palate come together
  they form the uvula
• Protects the lower airways by being extremely
  sensitive to tactile stimulation
• Can cause violent gagging and possibly vomiting

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Palatine Tonsils

• Lies in palato-glossal arch
• Lympathic tissue that is part of the immune
  system

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The Pharynx

• Generally known as the throat
• Divided into three areas
• Nasopharynyx
• Oropharynx
• Laryngopharynx

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Nasopharynx

• Located behind the nasal cavities
• Contains
• Adenoids or Pharyngeal tonsils
• Eustachian tube
• Runs between the back of the throat and middle
  ear
• Equilibrates pressure in the middle ear
• Acts like a pop-ff valve to release excess gas
  behind eardrum

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Oropharynx

• Located below soft palate down to base of tongue
• Only portion that can be seen without exam tools
• Contains
• Lingual tonsils at base of the tongue, tactile
  stimulation will cause gagging

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Laryngopharynx

• Also called the hypopharynx
• Located from base of the tongue to entrance of
  the esophagus
• Contains Epiglottis
• structure that protects the opening to the lower
  airways which is the glottis
• Strong but flexible fibro-cartilage flap that
  comes out of the larynx into the laryngopharynx

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Swallowing

• The most critical moment is when the food enters
  the laryngopharynx.
• Any mishap in coordination can lead to the food
  being aspirated into the lower airway
• There are more than 20 muscles that are involved
  in the act of swallowing
• The interaction of the tongue, palate and
  epiglottis in moving the food from the oral
  cavity to the oropharynx to the laryngopharynx
  and the esophagus

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Swallowing

• Food is broken down and lubricated in the oral
  cavity
• As one swallows the muscles of the tongue and
  mouth move food up and back
• Soft palate protects the nasopharynx
• Gravity moves food into oropharynx

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Swallowing

• When the tongue moves up forward the epiglottis
  moves down and backward
• Results in the glottis is covered as the food
  moves into esophagus
• Once food is in esophagus, the epiglottis moves
  back in place to allow gas to enter trachea
• http//www.hopkins-gi.org/multimedia/database/intr
  o_250_Swallow.swf

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The Larynx

• Located immediately below the pharynx
• Formed by
• Three large external cartilages
• Epiglottis
• Thyroid cartilage
• Cricoid cartilage
• Three pairs of internal cartilages
• Arytenoid cartilage
• Corniculate cartilage
• Cuneiform cartilage

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The Larynx
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Epiglottis
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External Cartilages

• All protect the airway
• Thyroid cartilage is open in the posterior but it
  is solid in the anterior to protect the vocal
  cords inside them
• Cricoid cartilage is rigid ring and is the only
  structure that encircles the airway

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Internal Cartilages

• Form a three sided pyramid of ligaments and
  muscles to control the movement of the vocal
  cords
• Pitch of the voice is controlled by tightening
  and loosening the cords
• Volume or loudness is controlled by the amount of
  air forced through the cords

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Interior of Larynx

• Viewing the glottis from above a clinician will
  see the base of the tongue on top
• Below the tongue will be the epiglottis between
  these two will stretch the 3 ligaments of the
  vallecula
• Egans page 173, figure 7-35

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Interior of Larynx

• The base of the glottal triangle is opposite from
  the base of the tongue
• Surrounding the true vocal cords are tissue folds
  that are called the vestibular fold or the false
  cords
• Vallecula space betweent the tongue
  epiglottis
• Important landmark in intubation

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Vocal Cords

• The vocal cords come together and separate during
  quiet breathing so that the glottis is always
  slightly open.
• A Valsalva maneuver or laryngospasm are the only
  time the glottis closed completely
• To close the glottis completely, not only
  requires bringing the vocal cords together but
  the person tightens all laryngeal muscles at the
  same time

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Valsalva Maneuver

• Purpose When the body requires positive
  pressure for expulsion
• Examples urination, defecation, birth, vomiting,
  coughing, sneezing
• Person must exhale forcefully against a closed
  glottis, building pressure in the abdomen and
  thorax
• Side effects
• Increase thoracic pressure decreases output of
  heart
• Increased pressure in head

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Coughing

• Cough reflex is triggered when there is an
  irritant in the tracheal bronchial tree
• Deep breath 12-15 mL/kg IBW,
• Inspiratory hold 3 seconds for air to get behind
  irritant
• Compression Valsalva maneuver. True cords
  close for 0.2 seconds, resulting intrathoracic
  pressure is 1001-200 cm H2O pressure
• Expulsion Glottis opens and velocity can reach
  300-500 LPM