Airway Anatomy Flashcards
Components of the Upper Airway
nose, mouth, pharynx, hypopharynx, larynx
Components of the Lower Airway
trachea, bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveoli
pharynx
extends from posterior aspect of nose to level of cricoid cartilage
nasopharynx location
C1
oropharynx location
C2-C3
hypo pharynx location
C5-C6
what is waldeyers tonsillar ring made up of
pharyngeal tonsils located in nasopharynx
palatine tonsils located in oropharynx
lingual tonsils located at base of tongue
larynx location (adults and kids)
C3-C6 in adults
C2-C4 in infants and children
9 cartilages in larynx
unpaired: epiglottis, thyroid, cricoid
paired: aretynoid, corniculate, cuneiform (a-corn)
epiglottis
sits at base of tongue and separates hypo pharynx from larynx and hangs over laryngeal opening
false vocal cords are also called
vestibular folds
true vocal cords
pale, white, ligamentous and attach to the thyroid anteriorly and aretynoids posteriorly
trachea
starts at C6, bifurcates at T5
10-15cm in length
16-20 cartilaginous rings anteriorly
posterior cricoaretynoid muscle action
abducts vocal cords and opens glottis
lateral cricoaretynoid muscle and action
adducts the vocal cords
aretynoid muscle action
adducts vocal cords
cricothyroid muscle action
produces cord tension, closure, elongates vocal cords. can result in laryngospasm
thyroearetynoid muscle action
shortens and relaxes vocal cords
intrinsic muscles of larynx
posterior cricoaretynoid lateral cricoaretynoid aretynoids cricothyroid thyroaretynoid
extrinsic muscles of larynx
sternohyoid sternothyroid thyrohyoid omohyoid stylohyoid mylohyoid
sternohyoid muscle action
draws hyoid bone inferiorly
sternothyroid muscle action
draw thyroid cartilage caudad
thyrohyoid muscle action
draws hyoid bone inferiorly
omohyoid muscle action
draws hyoid bone caudad
stylohyoid muscle action
elevates larynx
mylohyoid muscle action
elevates larynx
CN 5 Upper Airway Sensory innervation of nose
anterior septum and lateral walls
specifically called the ethmoidal nerve
maxillary division of trigeminal nerve: Upper Airway Sensory Innervation
posterior septum
cranial nerve IX (glossopharyngeal) innervation upper airway
tonsils, roof of pharynx, underside of soft palate
which sensory nerves innervate tongue
anterior 2/3 innervated by trigeminal (V)
posterior 1/3 innervated by glossopharyngeal (IX)
what does cranial nerve VII (facial nerve) innervate in upper airway
supplies muscles of facial expression
taste to anterior 2/3 of tongue
small amount of afferent conduction to oropharynx
motor control of stylohyoid laryngeal muscle
salivary glands
hypoglossal nerve (XII) innervation
provides motor innervation to most muscles of tongue
damage to this nerve can relax tongue, causing it to fall back and obstructing airway
vagus nerve X innervation
innervates airway below epiglottis
2 branches: SLN, RLN
superior laryngeal nerve
internal branch provides sensation to larynx from epiglottis to vocal cords (sensation ABOVE vocal cords)
external branch is a motor nerve, provides motor innervation to cricothyroid muscle
internal: sensory to lower pharynx, underside of epiglottis, larynx above cords
recurrent laryngeal nerve
provides sensation to larynx BELOW vocal cords.
innervates all muscles of larynx except cricothyroid muscle
motor: on right, leaves vagus at level of subclavian and loops up. on left, leaves vagus at level of aortic arched loops up
runs in the groove along the trachea
which nerve is responsible for laryngospasm
superior external laryngeal nerve
Superior Laryngeal Artery
blood supply to supraglottic laryngeal structures
carotid to superior thyroid artery
Inferior Laryngeal Artery
blood supply to infraglottic laryngeal structures
subclavian to inferior thyroid artery to ILA
Venous drainage of laryngeal blood supply
superior/inferior thyroid veins to SVC
Laryngeal Blood Supply arteries and veins to know
Common carotid artery inferior thyroid artery superior thyroid artery superior thyroid vein inferior thyroid vein
3 axes to line up
oral, pharyngeal, laryngeal
Grade 1-4 views
1: full view of glottic opening
2: posterior portion of glottic opening and aretynoid cartilage is visible
3: only tip of epiglottis is visible
4: soft palate visible; no recognizable laryngeal structures
MOANS difficult mask ventilation pneumonic
Mask seal obesity aged no teeth (esp upper) snores
predicting difficult intubation: LEMON
Look externally Evaluate mandibular space (TMJ) Mallampati classification Obstructions Neck mobility
