Laryngeal Anatomy Flashcards
What are the three unpaired cartilages of the larynx?
Epiglottis
Thyroid
Cricoid
The thyroid cartilage is suspended from the ______ via the _______
Hyoid
Thyrohyoid Ligament
The larynx lies anterior to which vertebrae?
C3-C6
What is the landmark for a cricothyrotomy?
The cricothyroid ligament
There is only one complete cartilaginous ring in the airway:
The cricoid cartilage
What are the three paired cartilages of the larynx?
Arytenoids
Corniculates
Cuneiform
Identify the orange and blue structures in the photo
Blue: Cuneiform
Orange: Corniculate
Identify the following structures:
- Anterior Commissure
- Epiglottis
- Ventricular Fold
- True Vocal Cord
- Aryepiglottic Fold
- Tracheal Rings
- Posterior Commissure
- Corniculate Cartilage
- Pyriform Sinus
- Cuneiform Cartilage
- Glottis
- Vallecula
What are some pre-op risk factors for laryngospasm?
Active URI in past 2 weeks
Second-hand smoke
GERD
Age < 1 yr
What are some intra-op risk factors for laryngospasm?
Light anesthesia (especially when lots of airway manipulation is necessary)
Saliva or blood in the upper airway
HYPERventilation/HYPOcapnea
Surgical Procedures anywhere in the airway
What are some interventions to reduce the risk of laryngospasm?
Avoid airway manipulation during light anesthesia
CPAP 5-10 during induction and after extubation
Suction pharynx before intubation
Extubate when the patient is deep or completely awake - not somewhere in between
Laryngeal lidocaine
IV Lidocaine before extubation
How should you treat a laryngospasm?
- 100% FiO2
- Remove noxious stimuli
- Deepen anesthesia via IV (if complete) or gas (if some air is moving)
- CPAP 15-20 with chin lift/jaw thrust
- Succinylcholine
If you give a child < 5 years succinylcholine for a laryngospasm, you also need to give ______
Atropine 0.02 mg/kg to prevent bradycardia
What is Larson’s Maneuver?
Applying pressure just behind the earlobe toward the base of the skull
Displaces the mandible and triggers pt to sigh, breaking the spasm
Apply for 5 sec, release for 10 and repeat
What non-depolarizing NMB can be given IM?
Rocuronium
During anesthesia, the upper airway can obstruct in three places:
Soft Palate
Tongue
Epiglottis
Relaxation of the _____ muscle causes the tongue to form an upper airway obstruction
genioglossus
Relaxation of the _____ muscle can cause obstruction at the level of the soft palate
tensor palatine
Identify the structure
Adenoid Tonsil
Identify the structure
Lingual Tonsil
When inserting a nasal airway, the bevel should face:
out, with the pointed end against the septum
Prevents the point from making contact with the turbinates
Anytime you place a device in the nose, you should place it between which two structures?
Inferior turbinate
Floor of the nasal cavity
Why do people revert to mouth breathing when they’re in distress?
Resistance through the nares is 2x higher than through the mouth
Due to pressure, the airway tends to ______ during inspiration
collapse
Negative pressure in the thorax pulls air in, which naturally makes the soft tissues likely to collapse
In normal states, which three muscles keep the airway from collapsing during inspiration?
These muscles are collectively called:
Tensor Palatine (opens the nasopharynx)
Genioglossus (opens the oropharynx)
Hyoid Muscles (opens the hypopharynx)
The Pharyngeal Dilators
In terms of airway structures, the trachea begins at _____ and ends at _____
The bottom of the cricoid
the carina
The right bronchus departs from midline at an angle of ______
The left bronchus has an angle of _____
25
45
RIGHT MAIN STEM INTUBATION MORE COMMON
What are Type 1 Pneumocytes?
Flat squamous cells
80% of Surface Area for gas exchange
Form tight junctions
What are Type II Pneumocytes?
Produce surfactant
Resistant to oxygen toxicity
Capable of cell division
Can produce Type I cells
What are Type III Pneumocytes?
Macrophages
Fight Infections, produce inflammation etc
In terms of vertebrae, the trachea begins at _____ and ends at _____
C6
T4-T5
Sensory innervation of the trachea is provided by:
RLN
What is the standard distance from the incisors to the carina?
~ 26 cm:
~13cm from the incisors to the larynx
~13cm from the larynx to the carina
Until the age of 5, what is the angle of the L and R bronchi at the carina?
55 degrees for BOTH
What decreases as an airway bifurcates?
Airflow Velocity
Amount of cartilage
Goblet Cells
Ciliated Cells
What increases as an airway bifurcates?
Number of airways
Cross-Sectional Area
Muscular Layer
What 2 landmarks correspond with the carina?
Angle of Louis
T4-T5
What is the afferent limb of the laryngospasm pathway?
What is the Efferent?
Afferent: Internal SLN
Efferent: Ext SLN and RLN
