Pharynx and larynx Flashcards
What protects the pharynx?
epiglottis
What is pharynx posterior to?
nasal and oral cavity, larynx
What are the layers of the pharynx from inside out?
mucus membrane
submucosa
pharyngo-basilar facia (fills gaps in walls of pharynx and is attached to base of skull)
Where is the buccopharyngeal fascia?
layer behind muscles of the pharynx infront of retropharyngeal space and prevertebral facia
meets buccinator muscle
What happens if the retropharyngeal space is puctured?
can go to heart
continous with thorax
What are the constrictors?
superior
middle
inferior (insert on thyroid cartiledge)
3 styrofoam cups overlapping
squeeze bolus towards esophagus
What happens when swallowing>
elevators lift pharynx to receive bolus
simultneous laryngeal elevation for closure and airway protection during swallowing
What nerve innervates most muscles of pharynx?
X
except for stylopharyngeous (IX) and oropharynx- tensor veli palatini = V
what is the most important blood supply to pharynx?
ascending pharyngeal from external cartoid A
ascending palatine and tonsilar of facial, pharyngeal branches and descending palatine of maxillary
What happens if the soft palate collapses?
sleep apnea
falls down, cant breathe when horizontal
Constrictors
Origin: Cricopharyngeus: lateral aspect of arch of cricoid cartilage. Thyropharyngeus: oblique line of laminar of thyroid cartilage and fibrous cricothyroid arch
Insertion: Cricopharyngeus: continuous with muscle of opposite side, behind pharynx. Thyropharyngeus : lower pharyngeal raphe
Action: Aids swallowing . Cricopharyngeus acts as upper esophageal sphincter
Nerve: Pharyngeal plexus (IX, X and sympathetic) via pharyngeal branch of X with its motor fibers from cranial accessory (XI)
stylopharyngeous
origin: medial aspect of styloid process
Insertion: posterolateral border of thyroid cartilage
action: elevates larynx and pharynx. aids swallowing
Nerve: muscular branch of glossopharyngeal nerve IX
levator veli palatini
origin: Apex of inferior surface of petrous temporal bone and medial rim of auditory tube
insertion: palatine aponeurosis
Action: elevates, retracts and lateral deviates soft palate. May open auditory tube on swallowing.
tensor veli palatini
origin: scaphoid fossa and medial aspect of spine of sphenoid bone
insertion: palatine aponeurosis (via pully of pterygoid hamulus)
action: tenses soft palate prior to elevation
nerve: nerve to medial pterygoid (main trunk of mandibular nerve) (V)
buccinator
origin: External alveolar margins of maxilla and mandible by molar teeth, to maxillary tubercle and pterygoid hamulus and posterior mylohyoid line respectively, then via pterygomandibular raphe between bones
insertion: Decussates at modiolus of mouth and interdigitates with opposite side
action: Aids mastication, tenses cheeks in blowing and whistling, aids closure of mouth
nerve: Buccal branch of facial nerve (VII)
mylohyoid
origin: Mylohyoid line on internal aspect of mandible
insertion: Anterior three quarters : midline raphe. posterior quarter: superior border of body of hyoid bone
action: Elevates hyoid bone, supports and raises floor of mouth. Aids in mastication and swallowing
nerve: Mylohyoid nerve (V)
hyoglossus
no sensory
origin: Superior border of greater cornu of hyoid bone
insertion: Lateral sides of tongue
action: Depresses tongue
nerve: Hypoglossal nerve (XII)
cricothyroid
Action: lengthens and tenses vocal cords by tilting thyroid cartilage forwards
Nerve: external branch of supieriorlaryngeal branch of vagus nerve X
What is the prefered location for trach?
cricothyroid b/c less blood
What is the only complete ring in trachea?
cricoid
all others are horseshoe C shaped
What nerve is the stripe on the barber pole and what muscle does it sit on top of?
IX
stylopharyngeus-> stylohyoid and styloglossus
What happens if sympathetic chain is cut?
Horner’s
What is the superior laryngeal nerve a branch of?
Vagus X
What does internal laryngeal nerve pierec?
thyrohyoid- sensation to vocal cord
What artery is the baroreceptor?
common carotid artery
9
What happens if the hyoid is fractured?
strangulation
What happens with a bilateral cut to recurrent laryngeal?
posterior carocoidaretynoid paralyzed
can’t open vocal cords because only abductor
die
Where hyoglossus located?
Between CN 12 and lingual artery
What is between the jugular and common carotid?
vagus X
What innervates cricothyroid?
external laryngeal
What 2 nerves branch off the vagus?
superior larygneal and recurrent laryngeal
what does the supieror laryngeal split to>
internal and external laryngeal
What does the internal laryngeal innervate?
sensory above the cords
What does the exertnal laryngeal innervate?
cricothyroid
What does the recurrent laryngeal innervate?
sensory below the cords and all other muscles (posterior cricothyroid, lateral cricoarytenoid, transverse and oblique arytenoids, vocalis, thyroarytenoid)
What is the only abductor of the cords?
Cricoarytenoid
What is the blood supply for the larynx?
via superior laryngeal of superior thyroid and inferior laryneal of inferior thyroid
same as thyroid!
What is the laryngeal skeleton?
3 single
thyroid cartilage, cricoid catilae, epiglottis
+ 3 paired (6)
corniculate, cuneiform, arytenoid cartilage
+ 2 joints synovial
cricothyroid cicoarytenoid
Over what vertebrae does the larynx extend?
C3-C6
When does the pharynx become the esophogus?
C6 lower border
What is the body guard of the body?
larynx- guard air way especially during swallowing
What is the larynx continous with?
laryngopharynx superior
trachea below C6
Where does food get stuck when you clear throat?
valleculae
Is the angle of the thyroid cartilage the same in men and women?
no! 90-120 degrees
Angle different for males and females- ladies voice different from male voice
men = adams apple
What is the onky complete ring in the respiratory system?
cricoid cartilage
rest are C shaped closed by trachealis
What is the joint that connects the cricoid and the thyroid?
cricothyroid joint
What does the epiglottis attach to?
back of hyoid bone by hyo-epiglottis ligament
anterior surface has taste buds
What pierces the thyrohyoid membrane?
pierced by the internal laryngeal nerve & superior laryngeal vessels
nerve and blood for upper larynx
Where do the arytenoid cartilages sit?
2 pyramids on top of cricoid cartilage
cricoarytenoid joint
2 processes- muscular and vocal
apex articulates with corniculate cartilage
Where are the conriculate and cuneiform cartilages (nodules?)
embedded in aryepiglottic fold
What are the two extrinsic membrane/ligaments?
thryohyoid membrane
circotracheal ligament
What are the two intrinsic membrane/ligaments?
1) quadrangular membrane (2)
stretched between epiglottis and arytenoids
-upper = aryepiglottic fold
-lower= vestublar ligament (FALSE vocal cord)
2) crico-thyroid ligament (1)
- upper = vocal ligament (true vocal cord) from angle of thyroid cartilage to vocal process of arytenoid
What is the false vocal fold?
vestibular ligament
lower quadrangular membrane
What is the true vocal fold?
vocal ligament off upper free border of cricothyroid ligament
What is the rima glottis?
space between vocal folds
If adducted, closed rima glottidis
If abducted, open rima glottidis
When should a cricothyrotomy be done?
After failure of valsalva maneuver when foreign body inhaled
last result to access airway- pierce between cricoid and thyroid- if you move cricoid or thyroid you stretch vocal cord
where is the most likely place for foreign body to be?
Piriform fossa (yellow)
remove of item may damage superior part of larynx- sensory- the branches of internal laryngeal nerve which lead to loss of sensation of the upper ½ of Larynx.
found in laryngeal inlet (either side of aryepiglottic fold)
Cricothyroid
ONLY TENSOR/stretcher of vocal ligament
external laryngeal nerve from CN X (exception)
Posterior cricoarytenoid
ONLY ABductor of vocal cords
ONLY opener of rima glottis
recurrent laryngeal from X
Lateral cricoarytenoid
ADDuctor of vocal folds
recurrent laryngeal from X
Transverse and oblique arytenoid
adductor of arytenoid cartilage
adduct intercarilaginous portion of vocal cords, close posterior rima glottidis)
recurrent laryngeal from X
What muscle is the exception that all laryngeal muscles are innervated by reccurrent laryngeal from X?
Cricothyroid = external laryngeal from X
develops from 4th arch (not 6th)
Thryo-arytenoid and vocalis
Relaxes vocal ligament
recurrent laryngeal
What muscle whispers?
vocalis
What divides the larynx into upper and lower parts?
vocal cords = watershed
What is the blood supply and sensory nerve to upper larynx?
superior laryngeal artery of superior thyroid artery
internal laryngeal nerve of superior laryngeal Vagus X
both PENETRATE thyrohyoid membrane
superior thyroid = first branch of external carotid
What is the blood supply and sensory nerve to lower larynx?
inferior laryngeal artery of inferior thyroid artery
recurrent laryngeal nerve of vagus X
What are the 3 pairs of laryngeal structures?
internal laryngeal n + superior laryngeal A
External laryngeal n + superior thyroid A
recurrent laryngeal n + inferior laryngeal A
Why should surgeon be careful during thyroidectomy?
blood supply of thyroid gland is close related to nerve supply of larynx so be careful of nerves
Where do the two recurrent nerves turn?
(goes to heart but turns around)
Right recurrent turns at right subclavian
Left recurrent turns at arch of aorta
