pharynx Flashcards
the pharynx is a combined passage for?
food and air
what level is the end of the pharynx and the beginning of the esophagus and trachea?
C6
the soft palate separates what?
nasopharynx and oropharynx
the trachea is anterior to what?
the esophagus
layers of the pharynx from outside-in
- buccopharangeal fascia
- musculosa (skeletal muscles: 3 semi-circular and 3 longitudinal)
- pharyngobasilar fascia (submucosa)
- mucosa
buccopharangeal fascia
- loose CT that covers the exterior of the pharynx
- continuous with the areolar fascia overlying buccinator muscle
- contains pharyngeal plexus of veins (IJV) and nerves (IX sensory; X motor)
3 semicircular muscles
superior, middle, and inferior constrictors
3 longitudinal muscles
stylopharyngeus, palatopharyngeus, salpingeopharyngeus
insertion of pharyngeal muscles
pharyngeal tuberosity
superior constrictor
- origin: pterygoid hamulus and pterygomandibular raphe
2. insertion: fans out in semicircle and meets in opposite side muscle in midline (pharyngeal) raphe
middle constrictor
- origin: stylohyoid ligamnet and hyoid bone
- insertion: fans out in semicircle and meets the opposite side muscle in midline (pharyngeal) raphe. Fibers overlap those of the superior constrictor
inferior constrictor
- origin: oblique line on the side of the thyroid cartilage and cricoid cartilage posterior to the cricothyroid muscle
- insertion: semicircle and meets the opposite side muscle in midline (pharyngeal) raphe. Fibers overlap those of superior and middle constrictors. Inferior fibers are horizontal and continuous with the upper esophagus (cricopharyngeus)
what innervates the 3 constrictors?
pharyngeal plexus of vagus
what contracts and relaxes during swallowing?
- constrictors contract sequentially –> peristaltic wave
- cricopharyngeus is constantly contracted to prevent air flow into esophagus BUT relaxes during swallowing
palatopharyngeus muscle
- origin: lateral edges of the palatal aponeurosis
- insertion: posterolateral wall of pharynx, tip of hyoid bone, posterior edge of thyroid cartilage
- raises the pharynx and larynx during swallowing
- supplied by vagus nerve
the vagus nerve innervates all of the longitudinal muscles except?
stylopharyngeus muscle – innervated by IX
salpingopharyngeus muscle
- origin: opening of auditory tube
- insertion: merges into palatopharyngeus
- raises pharynx and larynx during swallowing
- supplied by vagus
what muscle allows food to go to pharynx and not nasal cavity?
tensor palatine and LEVATOR PALATINE
stylopharyngeus muscle
- origin: medial aspect of styloid process and passes medially thru the overlap between the superior and middle constrictors
- insertion: same as palatopharyngeus (two muscles merge
- raises pharynx and larynx during swallowing
- supplied by glossopharyngeal nerve (CN IX)
gap bw skull base and superior constrictor
- pharyngobasilar fascia.
- passing thru– levator and tensor palatini ms, audiotry tube, ascending palatine artery (of facial)
gap bw superior and middle
stylopharyngeus ms, CN IX, CN XII, lingual artery, hyoglossus muscle
between middle and inferior constrictor
- passing thru thyrohyoid membrane
- internal laryngeal branch of superior laryngeal nerve (CN X), and superior laryngeal branch of superior thyroid artery (ext. carotid)
between inferior and esophagus
recurrent laryngeal nerve and inferior laryngeal branch of the inferior thyroid artery
nasopharynx
above soft palate, respiratory ep
oropharynx
bounded by soft palate and epiglottis
laryngopharynx
epiglottis level to the opening of the esophagus
where is the opening of the auditory tube?
nasopharynx
the opening of the auditory tube is reinforced by?
u-shaped cartilage
whats posterior to the auditory tube opening?
salpingopharyngeal fold
what’s posterior to the salpingopharyngeal fold?
pharyngeal recess
where are the nasopharyngeal tonsils?
roof and posterior wall of nasopharynx
hypertrophy may block the auditory tubes
what seals the opening bw the oropharynx and nasopharynx?
contraction of the soft palate
- during swallowing and phonation
- can also seal opening bw oral cavity and oropharynx during sucking
anterior pillar
palatoglossal arch
from soft palate to side of tongue and has palatoglossus muscle underneath
posterior pillar
palatopharyngeal arch
from soft palate to posterior wall of the pharynx and has the palatopharyngeus muscle underneath
what lie in between the anterior and posterior pillars?
palatine tonsils
tonsillar bed
deep to tonsils:
pharyngobasilar fascia, muscles, stylohyoid ligament, glossopharyngeal nerve
during tonsillectomy, where would the bleeding come from?
- tonsillar artery
- ascending palatine (facial)–primary
- dorsal lingual (lingual)
- ascending pharyngeal (ext carotid)
- lesser paltine (descending palatine–maxillary
laryngopharynx
from tip of epiglottis to beginning of esophagus (C6)
what does the epiglottis do?
seals the laryngeal opening when the pharynx and larynx are elevated upwards during swallowing
glossoepiglottic folds
3 mucosal folds between the epiglottis and posterior tongue
valleculae
small right and left depressions between the three glossoepigottic folds
pyriform recess
vertical gutter on the lateral side of the laryngopharynx between the lateral glossoepiglottic fold and lateral pharyngeal wall–> food passage on both sides of larynx
pharyngobasilar fascia (submucosa)
tough membrane that anchors the pharynx to the base of the skull in a U-shaped attachment
-medial pterygoid plate–> anterior border of the carotid canal –> pharyngeal tubercle
arterial supply to the pharynx
- ascending pharyngeal
- superior thyroid
- inferior thyroid
- ascending palatine
- dorsal lingual
- lesser palatine
vein supply of pharynx
- pharyngeal venus plexus
- communicates with the pterygoid venous plexus
- drains into the internal jugular vein
sensory nerve supply to pharynx
- glossopharyngeal (IX)–MAIN
- maxillary (V2)–soft palate and tonsillar fossa (lesser palatine nerve and roof (pharyngeal branch)
- internal branch of superior laryngeal branch of vagus (X)–> area surrounding laryngeal inlet
Sympathetic nerve supply to pharynx
Superior cervical ganglion
Parasympathetic supply to pharynx
All pharyngeal muscles are supplied by VAGUS (CN X) except the stylopharyngeus (CN IX)
Where is the pharyngeal plexus?
External surface of pharynx on the middle constrictor
Formation of pharyngeal plexus
- Motor root from vagus except stylopharyngeus which is supplied by special branch from glossopharyngeal and to palatine muscles except for TENSOR palatine which is supplied by branch from mandibular (v3)
- Sensory root from glossopharyngeal mainly to prophesy cells and laryngopharynx
- Sympathetic root from SCG to the blood vessels (vasomotor)
Taste
Facial: ant 2/3 and soft palate
Glossopharyngeal (IX) : post 1/3
Vagus (X): epiglottis
All palatine muscles are supplied by —— except ——
All are supplied by X except tensor (V3)
All intrinsic laryngeal muscles are supplied by —- except —-
All intrinsic laryngeal muscles are supplied by recurrent laryngeal nerve except Chico thyroid
All infra hyoid muscles are supplied by —- except ——
All are supplied by ansa cervicalis except thyrohyoid (C1 via hypoglossal nerve)
What nerves are involved in the gag reflex?
Sensory— glossopharyngeal (IX)
Motor—vagus (X)
Bulbar palsy
LMN lesion in CN IX, X, XI, and XII
deviation of uvula away from the affected side
No movement or gag reflex on the affected side
Boundaries of retropharyngeal space
Superior: skull base Inferior: superior mediastinum (including major blood vessels of the heart) Anterior: buccopharyngeal fascia Posterior: alar (pre-vertebral) fascia Lateral: carotid sheath
Phases of swallowing
- Prep: formation of bolts
- Oral: pushing the bolts back to the oropharynx
- Pharyngeal: pushing the bolts down to the esophagus
- Esophageal: pushing the bolus down into the stomach
Pharyngeal phase
- receptors in soft palate and oropharynx stimulate deglutition center in medulla and lower pons
- soft palate elevated to seal nasopharyngeal and prevent nasopharyngeal regurgitation
- pharyngeal constrictors contract and cricopharyngeus opens and immediately closes and the larynx is shut down
- during pharyngeal phase— chewing, breathing, coughing, vomiting are inhibited
Esophageal phase
- peristaltic movement
- bolus travels down the esophagus terminating into the stomach
- esophagus becomes expanded only at level of bolus
- submucosa contains lot of mucus glands—liquify and lube
