Unit 3: The Airways The Upper Airways

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Unit 2: The Airways
The Upper Airways
RSPT 1207
Cardio Pulmonary Anatomy &
Physiology
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
The Upper Airways
• Consists of:
– The nose
– Oral cavities
– The pharynx
– The larynx
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
The Nose
• Midline, external
and internal
structure
• Upper third is bone
and covered by skin
• Lower 2/3 is
cartilage
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
Major Structures of the Nose
Major Structures of the Nose
Major Structures of the Nose
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
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
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
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
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
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
Oral Cavity
• Simply known as the mouth
• Functions:
– Alternate passageway for breathing
– Start of the alimentary canal
– Contains major speech structures
– Facial expressions
Oral Cavity
• Anteriorly begins
with lips and mouth
• Follows with oral
vestibule and teeth
and gums
• Oral cavity begins
after the teeth
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.
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
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)
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
Palatine Tonsils
• Lies in palato-glossal arch
• Lympathic tissue that is part of the
immune system
The Pharynx
• Generally known as the throat
• Divided into three areas:
– Nasopharynyx
– Oropharynx
– Laryngopharynx
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
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
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
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
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
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.hopkinsgi.org/multimedia/database/intro_250_Swallow.swf
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
The Larynx
Epiglottis
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
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
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
• Egan’s page 173, figure 7-35
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
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
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
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
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