Airway Flashcards
Larynx
SLN branch of
Divides into
CNX Vagus
Internal & external laryngeal
External laryngeal innervates (comes from)
SLN
Internal laryngeal innervates where
Glottis
supraglottis
Inferior epiglottis
lingual surface of the epiglottis supply
CNXI Glossophar
Vocal cords in a cadaver
Intermediate
Recurrent laryngeal
Branch of
supplies motor & sensory
Injury
Vagus branch
Intrinsic muscles larynx (-cricothyroid)
Sensory below vocal cords
Blat transection = ibability of the posterior cricoarytenoid muscles to adbuct - stridor
Glossopharyngeal
innervates what
Sensory - posterior 3rd of tongue Pharynx carotid sinus & body Motor -> stylopharyngeal rasympathetic supply to the parotid gland.
Sensory innervation of the airway
What supply nasacl vacity
What supply posterior tongue pharynx and epiglottis
What supply laryn - above VC
Below VC
What control cricothyroid muscle
The sensory innervation of the airway can be separated into three components.
The nasal cavity and nasopharynx are supplied by the maxillary branch of the trigeminal nerve.
The glossopharyngeal nerve innervates the posterior third of the tongue, pharynx and structures above the epiglottis.
The larynx is served by the internal branch of the superior laryngeal nerve above the vocal cords and the recurrent laryngeal nerve below the cords.
The external branch of the superior laryngeal nerve is a motor nerve controlling the cricothyroid muscle.
Larynx - sensory innervation
Sensation from the larynx is conveyed by two branches of the vagus nerve. The internal branch of the superior laryngeal nerve supplies the mucosa above the cords and the recurrent laryngeal nerve innervates the subglottis.
The trachea is how long
Start where ends where
How many Cartilagnious rings
How many generations of airway passage in trachebronchial tree
What is the blood supply to the trachea
The trachea of an adult is approximately 15 cm long, and it extends from the lower border of the cricoid cartilage at the level of the 6th cervical vertebra.
The trachea of an adult is approximately 15 cm long, and it extends from the lower border of the cricoid cartilage at the level of the 6th cervical vertebra.
It terminates at the bronchial bifurcation or carina, which is between T4 and T6 (the variation is due to changes during breathing).
The trachea has 16-20 C-shaped cartilaginous rings that maintain its patency.
The tracheobronchial tree comprises 23 generations of air passages (not 25) from the trachea to the alveoli. The trachea is the first.
The blood supply to the trachea is from the inferior thyroid arteries, which are branches of the thyrocervical trunk, which arise from the first part of the subclavian artery.
Paed a/way
when is the tongue normal proportins
Vocal cords lie oppsite what level
when does it reach c5 c6
What is the idfference in larynx
why
what is the narrowest part of the paed airway
vs adult
what level is carina
what age alveolar diffevleop
how do neonates breath
The tongue is large during the neonatal period, reaching normal proportions by the age of 1 year. The vocal cords lie opposite C4 and only reach the adult position opposite C5/6 by the age of 4 years (not 1 year).
The larynx is more anterior in infants, due to the underdeveloped cricoid cartilage, which is why the cricoid ring is the narrowest part of the paediatric airway (in the adult the narrowest part of the airway is at the level of the vocal cords). The epiglottis is relatively large and inclines at an angle of 45 degrees to the laryngeal opening.
The carina is at the level of T2 in the paediatric population (T4 in adults) and the left and right main bronchi divide at similar angles.
Neonates have a comparatively small number of alveoli and this number increases to a maximum by the age of 8 years (not 3 years).
Neonates are obligatory nose breathers and any obstruction can cause respiratory distress (for example, choanal atresia).
pharynx
extened where to wair
how many muscle pairing
how does venous draing leave
How many layer in the wall
What is the senosry suppy
naso
oro
laryngo
what is the motor suply
The pharynx is a midline structure that extends from the skull base to the level of C6. It consists of three paired muscles (superior, middle, and inferior constrictors) and three unpaired muscles (stylopharyngeus, salpingopharyngeus, and palatopharyngeus). The venous drainage of the pharynx is via the pharyngeal plexus into the internal jugular vein.
The pharynx contains four layers (mucosa, submucosa, muscular and loose connective tissue).
The sensory supply to the pharynx is as follows:
Nasopharynx - pharyngeal branch of the maxillary nerve
Oropharynx - glossopharyngeal nerve
Laryngopharynx - vagus nerve.
The motor innervation of the pharynx is from the vagus nerve (except stylopharyngeus which is supplied by the glossopharyngeal nerve).
Trachea starts were end where
how long
RMB angles
LMB angles
The human trachea starts at C6 and extends to the level of T4 where the trachea bifurcates. It is approximately 15 cm long in an adult.
The right main bronchus separates from the trachea at a 25° angle, whereas the left main bronchus separates at an angle of 45°.
PRox to dist tracheobronch tree
The respiratory or tracheobronchial tree is subdivided into the conducting and the respiratory zones.
Proximal to distal include:
Conducting zone:
Trachea Bronchi Bronchioles Terminal bronchioles Respiratory zone:
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Laryngeal anatomy
What is the space between true vocal cords
How are the intrinsic muscle of larynx supplied -
whats the exception
Muscle of larynx
what abducts cords
what adducts cords
what are the sphincters
How is vocal cord tension regulated
The rima glottidis is the space between the true vocal cords and the ventricle of the larynx is the fossa between the true and false cords. The part between the inlet and the false vocal cords is the vestibule.
All of the intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerves, except the cricothyroid which is supplied by the external branch of the superior laryngeal nerve (not internal branch).
Regarding the intrinsic muscles of the larynx:
The posterior cricoarytenoids abduct the cords
The lateral cricoarytenoids and interarytenoids adduct the cords
The sphincters to the vestibule are the aryepiglottics and the thyroepiglottics.
Vocal cord tension is regulated by the
Cricothyroids (tensors)
Thyroarytenoids (relaxors) and the
Vocales (fine adjustments).
Laryngeal nerves come from what
Sup lar - many branch
what is sensory
What supllies cricothyroid
What supplies intrisnc muslcs
The laryngeal nerves are derived from the vagus nerves.
The superior laryngeal has two branches
The internal laryngeal nerve is a sensory nerve supplying the mucosae of:
larynx above the vocal cords
epiglottis
vallecullae
special visceral sensory fibres that carry the sensation of taste from the region of the valleculae
The external laryngeal which supplies cricothyroid and the inferior constrictors.
The recurrent laryngeal supplies all the intrinsic muscles except cricothyroid and the mucous membranes of the larynx below the vocal cords.
Bilateral recurrent laryngeal nerve damage can lead to acute severe airway obstruction.
Why voice change after thyroidectomy
About 10-15% of patients experience a variable degree of temporary subjective voice change after thyroidectomy. This is typically described as a “frog in the throat” or “cracking “ of the voice or a “weak” voice. These changes are temporary and last a few days to a few weeks.
They are attributed to swelling of the muscles in the area of the dissection and /or inflammation and oedema of the larynx related to the dissection in the area, or minor trauma from the tracheal tube.
The superior laryngeal nerve (EBSLN) runs along the upper part of the thyroid gland on both sides. These nerves innervate muscles that fine-tune the vocal cords. If they are injured the voice quality is usually fairly normal but creating high-pitched sounds may difficult. The incidence of injury to the EBSLN is approximately 2%.
The incidence of injuries to the recurrent laryngeal nerve (RLN) has been reported as 1% - 14%. The RLN supplies all the intrinsic muscles of the larynx except the cricothyoid muscle.
This complication is generally unilateral and transient, but occasionally it can be bilateral and permanent and it may be either deliberate or accidental. The permanent lesion of damaged RLN often manifests as an irreversible dysfunction of phonation and is the most common complication following thyroid surgery.
Dislocation of the crico-arytenoid joint is an uncommon complication of tracheal intubation and blunt neck trauma. The incidence is less that 1 in 1,000.
The incidence of vocal cord polyp is 0.8%.
Cricoid
sellick
prevent passive regurg acidic contents (not vomitus)
44n - compress oes cricoid + body of c6
not apply if vomiting - rupture
may reduce view
Voice changes in LN damage
SLN = weak voice
(slackening of the cords)
partial recurrent - hoarse
Completle bilat recurr laryn - lost
which is affected more abductor or adductor by partial RLN damage
Partial - affect abductors > adductors
semons law
Most at risk of aspiration when supine
apical segment of Lower lobes
emerge in AP direction - risk supine
right mid lobe - risk prone
rll - sat up
Trachea bifurc at what level
which is short r or lmb
how many basal lobes
how far is apex above clavicle
horizontal fissure is where to where
Bifruc T4
RMB short LMB
both L + R basal lobes 5 branches
apex 4cm above clavicle
horizontal fissure follow from line 4th costochondral jxn -> oblique fissure
