APEX: AIRWAY ANATOMY and Review TEST Flashcards
Adducts VOCAL Cords muscle of the larynx
Lateral Cricoarytenoids
ABDUCTS VOCAL Cords muscle of the larynx
POSTERIOR Cricoarytenoids
Elongates vocal cords
CRICO(T)HYROID
Shorten Vocal cords
Thyroarytenoids
Intrinsic Muscles that tense and relax vocal cords
Cricothyroid - tenses
(T)hyroa(R)ytenoids_ THEY RELAX
Extrinsic Muscles of the Larynx: ELEVATE the larynx ( Style-GENI-MY-THY-Di- STyloP
Stylohoid Geniohyoid Mylohyoid Thyrohyoid Digastic Stylopharyngeus
Extrinsic Muscles of the Larynx: DEPRESSES the larynx (SOS)
Omohyoid
Sternohyoid
Sternothyroid
Closes posterior commissure of the glottis
interarytenoids
Key players of the Laryngospasm reflex
Cricothyroid muscles
What is the ONLY intrinsic laryngeal muscles that receive motor innervation from EXTERNAL branch of the SLN
CRICOTHYROID muscles
RLN course underneath the
Aortic arc before ascends the trachea towards the larynx
What are causes of left RLN injury>
PDA ligation
Left atrial enlargement secondary to mitral stenosis
The Superior Laryngal nerve innervates
underside of the epiglottis
Cricothyroid muscles
4 nerves that should come to mind with innervation of the airway
Trigeminal
Glossopharyngeal
SLN (external or internal)
RLN
The SLN branches off the
Vagus nerve just beyond the jugular foremen at the skull base
Where does the SLN divides into internal and external branches
At the level of they hyoid
The internal branch of the SLN penetrates the thyrohyoid membrane between the
Greater cornu of the hyoid bone
The internal branch of the SLN penetrates the _____while the external branch of the SLN penetrates the ________
Thyrohyoid
Cricothyroid
The recurrent laryngeal nerve branches off the
Vagus nerve inside the thorax
The right RLN loops under the ______while the left RLN loops under the
Subclavian artery
Aortic ARCH
After the right RLN and the Left RLN loop under the vascular structure both nerves ascend the
Tracheoesophageal groove to join the larynx
Which nerve is more likely to be injured and why?
The left RLN due to its location in the thorax.
What are the branches of the trigeminal nerve (CN V)
V1: Ophtalmic (anterior ethmoidal)
V2: Maxillary (sphenopalatine)
V3: Mandibular (lingual
V3 mandibular branch is responsible for sensory innervation of the airway of what part
Anterior 2/3 of tongue
Turbinates and septum are innervated by
V2 (maxillary) sphenopalatine
Nares and Anterior 1/3 of nasal septum innervated by
V1 Opthalmic (anterior ethmoidal)
Soft palate innervated by
Glossopharyngeal (CN IX)
Oropharynx innervated by
Glossopharyngeal (CN IX)
Tonsils innervated by
Glossopharyngeal (CN IX)
Posterior 1/3 of tongue innervated by
Glossopharyngeal (CN IX)
Vallecula innervated by
Glossopharyngeal (CN IX)
Anterior side of the epiglottis
Glossopharyngeal (CN IX)
The true vocal cords are
Ligaments
WHich innervates structure below the vocal cords?
RLN
Tuning fork for the voice
SLN (external branch)
Injury to the trunk of the superior laryngeal nerve or the external branch causes
hoarseness (Because the vocal cords can’t be tense)
RLN injury can be classified as
Unilateral
acute Bilateral
Unilateral injury of RLN results in _______ Does it cause resp distress?
paralysis of the ipsilateral vocal cords abductors. DOES NOT CAUSE RESP DISTRESS
Bilateral injury of RLN results in _______ Does it cause resp distress?
bilateral paralysis of the ipsilateral vocal cords abductors. Danger because the TENSING action of the Cricothyroid muscles act unopposed. RISK FOR STRIDOR and RESP DISTRESS. Requires intubation or a SURGICAL AIRWAY
Procedure that put patient at risk for RLN injury on the left side
PDA ligation
Left atrial enlargement and mitral stenois
AA Aneurysm
Thoracic tumor
Procedure that put patient at risk for RLN injury on either side (R or L)
External pressure on ET tube Extern pressure on LMA Thryroid and parathyroid surgeires Neck stretching Tumor
What are the 3 key airway blocks
Glossopharyngeal
Superior Laryngeal
Transtracheal
To block the SLN, LA is injected where?
just below the border of the GREATER CORNU of the HYOID BONE.
1 ml is injected outside the thyrohyoid membrane
2ml are injected just beneath the thyrohyoid membrane.
In what block in the needle inserted at the base of the palatoglossal arch (anterior tonsillar pillar) ?
Glossopharyngeal block
You are performing a glossopharyngeal block and you aspirate air, what does that mean?
Needle is too deep
You are performing a glossopharyngeal block and you aspirate BLOOD, what does that mean?
Needle should be withdrawn and redirected medially (Carotid artery is very close)
There is a risk of _________with glossopharyngeal block which will be manifested as ______
Intracarotid injection
Seizure
Superior Laryngeal block : where is the anesthetic injected?
Inferior border of the greater cornu of the hyoid bone
You are performing a Superior Laryngeal block and you aspirate air, what does that mean?
Needle is too deep
Transtracheal block, the needle is advance in a_____as it penetrates the _______membrane
Caudal; cricothyroid membrane
During the transtracheal block, after aspiration and before injection what should the patient do? and what does the practitioner do ?
Take a DEEP BREATH ; During that inspiration part of that deep breath, 3-5ml of LA is injected into the tracheal lumen. The PATIENT will cough , SPRAYING THE LA up through the vocal cords
The adult larynx extends from
C3-C6
Larynx consists of
One bone, ligaments and 9 cartilages (3 paired and 3 unpaired.
What is the only bone in the body that does not articulate with another bone?
HYOID
Form the main support of the larynx and attaches to the thyroid cartilage via the THYROHYOID ligament
Hyoid
Anterior ligaments are the
Thyrohyoid membrane
Cricothyroid membrane
Which ligament attaches the larynx to the hyoid bone
Thyrohyoid membrane
Which ligament attaches the cricoid and thyroid cartilages
Cricothyroid membrane
What is puncture during the cricothyroidotomy ?
Cricothyroid membrane
What are the paired cartilages?
Arytenoid
Cuneiform
Corniculate
What can you not see during direct laryngoscopy ?
Arytenoids
What do the corniculate and cuneiform cartilates do?
provide structure to the aryepiglottic folds.
What cartilages shapes like 3-sided pyramids
Arytenoids
2 conditions that may impair movement of the arytenoids,
RA
SLE
Provides a mechanical barrier between pharynx and the laryngeal opening?
Epiglottis
What is the space between the base of the tongue and the anterior side of the epiglottis
Vallecula
Which ligament connects the epiglottis to the thyroid cartilage>
Thyroepiglottic
Provide structure and protection to the larynx
Thyroid cartilage
What is the largest cartilage in the larynx?
Thyroid
Forms Adam’s appled
Thyroid
Cartilage most caudal to the larynx
Cricoid
What is the narrowest part of the pediatric airway ?
Vocal cords or cricoid ring
What is laryngospasm ?
Sustained and involuntary contraction of the laryngeal muscles that results in the inability to ventilate, results in complete airway obstruction, Negative pressure pulmonary edema, gastric aspiration, cardiac arrest.
Pre-anesthetic risk factors for laryngospasm?
Active or recent URI Exposure to 2nd hand smoke Reactive airway disease GERD Age< 1 year
INTRA OP risk factors for laryngospasm?
Light anesthesia with airway manipulation Saliva or blood in upper airway Hyperventilation Hypocapnia Surgical procedure involving airway
Explain the REFLEX PATHWAY?
Afferent limb : SLN INTERNAL BRANCH
EFFERENT limb: SLN EXTERNAL branch+ RLN
What are sings of laryngospasm?
Inspiratory stridor
Suprasternal or supraclavicular retraction during inspiration
Rocking horse appearance of the chest wall
Increasing diaphragmatic excursion
Lower rib flailling
Factors that reduce the likelihood of laryngospasm
Avoidance of airway manipulation during light anesthesia
CPAP 5-10 cm H2O during inhalation induction as well as immediately post intubation
Remove pharyngeal secretion and blood before extubation
Laryngeal lidocaine
IV lidocaine before extubation
Hypercapnia/hypoventilation
PaO2 < 50 mmHg
Treatment of Laryngospasm : In order of importance
- FiO2 100%
- Remove noxious stimulation
- Deepen anesthesia by increasing gas concentration or with a small dose of propofol or lidocaine
- CPAP 15-20 cm while doing maneuvers to open the airway such as the head extension, chin lift, larson’s maneuver
- If IV access Succinylcholine 2mg/kg for infant. 0.1 to 1 mg/kg for adult
If no IV , 5mg/kg for infant, 4 mg/kg for children or adult
When treating laryngospasm with succinylcholine in children less than 5 years what should they all receive
Atropine 0.02mg/kg with succinylcholine to prevent bradycardia.
What is the larson’s maneuver
Application of firm pressure to the laryngospasm notch located being the EARLOBE. Pressure is applied bilaterally towards the skull base. applied pressure 3-5 seconds then released 5-10 seconds
What does the larson’s maneuver accomplisH?
Displaces the mandible anteriorly to help open the airway
Breaks laryngospasm by causing the lightly anesthesized patient to sigh.
What is the Valsava’s maneuvers?
Exhalation against a closed glottis
Risk of valsava’s maneuvers
Increased pressure in the Thorax, abdomen and brain
What is the MULLER’s maneuvers?
Inhalation against a closed glottis
Risk of Muller’s maneuvers
Subatmospheric pressure in the thorax –> Negative pressure pulmonary edema
Tensor palatine muscle relaxation will most likely cause airway obstruction at which level ?
soft palate
During anesthesia, where are the 3 places where the upper airway can obstruct
soft palate
Tongue
Epiglottis
Relaxation of the tensor palatine muscle
Soft palate
Relaxation of the GENIOGLOSSUS muscle
Tongue
Relaxation of the HYOID muscles
Epiglottis
Primary functions of the upper airway including
Warming and humidifying muscle inspired air, filtering particulate matter and preventing aspiration
During normal inspiration, what occurs
Diaphragmatic contraction and chest wall expansion create a negative pressure to draw air into the lungs.
Factors that impair airway patency
Condiation that reduce the diameter of the tube
Condition that reduce the size of the box
Think of the pharynx as a collapsible tube that lives inside a box> this box is formed by the borders of the surrounding such as the
tongue, soft palate, pharyngeal tissue and cervical spine
What are the 3 sets of dilator muscles that prevents airway obstruction in the awake state?
Tensor palatine
Genioglossus
Hyoid muscles
Function of the tensor palatine
Opens the nasopharynx
Function fo teh GENIOGLOSSUS
Opens the oropharynx
Function of the Hyoid muscles
Opens the hypopharynx
from top to bottom
NOH (Naso–>oro–> Hypo) Pharynx
Explain the 2 competing explanations for the primary cause of UPPER AIRWAY OBSTRUCTION during anesthesia and sedation
- Tongue obstructs the airway - Genioglossus muscle relaxes and allows the tongue to obstruct the airway
- Soft plate obstructs the airway- The TENSOR palatine muscle relaxes and allows the soft palate to obstructs the airway
When compared to the trachea, which of the following is increased in the terminal bronchioles?
Cross-sectional area
Tracheobronchial tree is a branching network of airways that includes the
Trachea –> Bronchi–> Bronchioles
In terms of airway, a division is
where an airway divides into 2 or more smaller airways
How many division or generation in humans
23-25
At each division, the diameter of the new branches becomes_____But the cross sectional area ____
smaller ; increases
At each At each division, the diameter of the new branches becomes smaller But the cross sectional area increases, this explains
Why airflow velocity SLOWS as you move down the tracheobronchial tree.
The trachea contains ______And ________ while the terminal bronchioles contains________
Cartilage (C-shaped rings) Goblet cells (mucus secretion)
Where does the lower airway begins and ends?
Begins At trachea , ends at the alveoli
Where the trachea begins and ends
C5 ; T4-5 at the carina
Length of trachea; width
10-13 cm long
2-3 cm
Tracheal cells
Ciliated columnar epithelium
Sensory innervation of the trachea
Vagus
Blood supply of the trachea
Inferior thyroid artery
Superior thyroid artery
Bronchial artery
Internal thoracic artery
At level of the CARINA_______ corresponds to _______
T4-T5
Corresponds to ANGLE OF LOUIS
Right mainstem bronchus is _____; and ______degrees take off
2.5 cm long ; 25 degrees take off
Left mainstem bronchus is _____; and ______degrees take off
5cm long; 45 degrees take off
Mainstem bronchi types of cells
CUBOIDAL epithelium
Alveoli number
300 million by age 9
Alveoli tissue
Squamous epithelium
Which structure allows air movement between alveoli?
PORES of KOHN
Type I pneumocytes role
Provide surface for gas exchange
Which type of pneumocytes cover 80% of alveolar surface?
Type I pneumocytes
Type II pneumocytes role
Produce surfactant
Pneumocytes resistant to Oxygen toxicity
Type II
What pneumocytes can produce type I cells
Type II
Pneumocytes capable of cells division
Type II
Pneumocytes that are macrophages and produce inflammatory response
Type III
Pneumocytes that fights lung infection
Type III
What is the distance between from the incisors to the larynx is ?
13cm
What is the distance between from the larynx to the carina is about
13 cm
Distance from incisors to carina is
26cm
Neck flexion makes distance from incisors to carina
ShORTER distance
Neck extension makes distance from incisors to carina
Increases distance
with NECK EXTENSION and NECK FLEXION, remember what happens to the tube?
The tube goes where the nose goes
Characteristics of progressive airway division : What increase as the airway bifurcates
Number of airway
Cross sectional area
Muscular layer
Characteristics of progressive airway division : What decrease as the airway bifurcates
Airflow velocity
Amount of cartilage
Goblet cells (produce mucus)
Cillated Cells (clear mucus)
Order of cartilage from most superior to most inferior
Epiglottis
Corniculate
Arytenoids
Cricoid
Location of infant’s larynx is
C2-C4
What are the landmark for larson’s maneuver?
Posterior: mastoid
Superior: skull base
Anterior : Ramus of mandible