A4 - pharynx and larynx Flashcards
the pharynx is a muscular tube that connects what?
the oral and nasal cavity to the larynx and oesophagus
where does the pharynx begin and end?
begins at base of skull and ends at the inferior border of the cricoid cartilage (C6)
what are the 3 parts of the pharynx?
1) nasopharynx - posterior to the nose and superior to the soft palate
2) oropharynx - posterior to the mouth
3) laryngopharynx - posterior to the larynx
where is the nasopharynx?
between base of skull and the soft palate
the nasopharynx is continuous with the nasal cavity and performs what function?
a respiratory function by conditioning inspired air and propagating it into the larynx
the nose opens into the nasopharynx though what?
2 choanae
what is the nasopharynx lined with?
respiratory epithelium = ciliated pseudostratified columnar epithelium with goblet cells
what does the posterosuperior nasopharynx contain?
adenoid tonsils (aka pharyngeal tonsils) — enlarge between 3-8 years then regress
what does the pharyngotympanic tube do?
connects the middle ear to the nasopharynx and drains mucous from the middle ear
there is a lot of _____ tissue, which forms an incomplete _____ ring around the superior part of the pharynx. the tissue is aggregated in certain places, forming _____
there is a lot of lymphoid tissue, which forms an incomplete tonsillar ring around the superior part of the pharynx. the tissue is aggregated in certain places, forming tonsils
what is another name for the adenoids?
pharyngeal tonsils
where is the pharyngeal tonsil found?
in the mucous membrane of the roof and posterior wall of the nasopharynx
where is the tubal tonsil?
lies in the submucosa near the pharyngeal opening of the pharyngotympanic tube
what is the oropharynx bounded by?
the soft palate superiorly, the base of the tongue inferiorly, and the palatoglossal and palatopharyngeal arches laterally
where does the oropharynx extend?
from the soft palate to the superior border of the epiglottis
what type of function does the oropharynx have?
digestive
what is the oropharynx lined with?
stratified squamous epithelium
the opening of the oropharynx viewed from the mouth is called the what?
fauces
what are the palatine tonsils?
collections of lymphoid tissue on each side of the oropharynx in the interval between the palatine arches — these tonsils however do not fill the fossa between the arches in adults
what also protrudes into the oropharynx?
uvula
what is Waldeyer’s ring?
the ring of lymphoid tissue (MALT - mucosa-associated lymphoid tissue) which surrounds the naso and oropharynx. this collection of lymphoid tissue consists of the pharyngeal tonsils (adenoids), palatine tonsils and lingual tonsils. the purpose of this ring is too produce B cells, which act as the first line of defence against exogenous aggressors that have been inhaled or ingested.
the lingual tonsils are located on the dorsal surface of the base of the tongue
what does Waldeyer’s ring consist of?
- pharyngeal tonsil
- tubal tonsil x2
- palatine tonsil x2
- lingual tonsil
label
what is the laryngopharynx located between?
the superior border of the epiglottis and inferior border of the cricoid cartilage (C6)
what is posterior to the larynx?
laryngopharynx
what is the laryngopharynx lined with?
stratified squamous epithelium
what bodies is the laryngopharynx related to?
C4-C6
what muscles make up the posterior and lateral walls of the laryngopharynx?
middle + inferior pharyngeal constrictor
the larynx projects anteriorly from the laryngopharynx via what?
laryngeal inlet
what is the name of the small depression in the laryngopharyngeal cavity on either side of the laryngeal inlet?
piriforim fossa (recess)
the piriformis fossa is mucosa lined and is separated from the laryngeal inlet by what?
aryepiglottic fold
what are the 2 groups of muscles of the pharynx?
- inner longitudinal
- outer circular — pharyngeal constrictors
name the muscles of the pharynx
EXTERNAL —> pharyngeal constrictors : superior, middle and inferior
INTERNAL —> palatopharyngeus, stylopharyngeus and salpingopharyngeus
what is the main action of the external muscles of the pharynx?
constrict walls of pharynx during swallowing
what are the main actions of the internal muscles of the pharynx?
elevate (shorten and widen) pharynx and larynx during swallowing and speaking
name the 3 external pharyngeal muscles and what part of the pharynx they are in
- superior pharyngeal constrictor — in oropharynx
- middle pharyngeal constrictor — in laryngopharynx
- inferior pharyngeal constrictor — in laryngopharynx
origin, insertion and innervation of superior constrictor
O = pterygoid hamulus, pterygo-mandibular raphe, posterior end of mylohyoid line of mandible, and side of tongue
I = pharyngeal tubercle and the pharyngeal raphe
innervation = pharyngeal branch of vagus and pharyngeal plexus (CN X)
origin, insertion and innervation of middle constrictor
O = stylohyoid ligament and hyoid bone
I = pharyngeal raphe
innervation = pharyngeal plexus
origin, insertion and innervation of inferior constrictor
O = oblique line of thyroid cartilage and side of cricoid cartilage
I = pharyngeal raphe
innervation = pharyngeal plexus
name the internal muscles of pharynx
- palatopharyngeus
- salpingopharyngeus
- stylopharyngeus
origin, insertion and innervation of palatopharyngeus
O = hard palate and palatine aponeurosis
I = lateral wall of pharynx, posterior border of thyroid cartilage
innervation = pharyngeal plexus
origin, insertion and innervation of salpingopharyngeus
O = pharyngotympanic tube
I = lateral pharyngeal wall
innervation = pharyngeal plexus
origin, insertion and innervation of stylopharyngeus
O = styloid process of temporal bone
I = posterior and superior borders of thyroid cartilage with palatopharyngeus
innervation = receives motor innervation via glossopharyngeal nerve (CN IX)
which muscle of the pharynx assists in equalising pressure in the middle ear?
salpingopharyngeus
venous drainage of the pharynx?
pharyngeal venous plexus — drains into IJV
arterial supply of the pharynx?
branches of the external carotid:
- ascending pharyngeal artery
- branches of facial artery
- branches of the lingual and maxillary arteries
what does the pharyngeal plexus overlie?
the middle pharyngeal constrictor
the pharyngeal plexus supplies motor and sensory innervation to the majority of the pharynx except what?
nasopharynx
what does the pharyngeal plexus consist of?
- pharyngeal branches of CN IX
- pharyngeal branch of CN X
- branches from the external laryngeal nerve
- sympathetic fibres from the superior cervical ganglion
motor from CN X
sensory from CN IX
cervical sympathetic
the pharynx receives sensory innervation from what?
glossopharyngeal nerve = CN IX
the anterior and superior aspect of the nasopharynx is innervated by what?
maxillary nerve (V2)
the inferior aspect of the laryngopharynx (surrounding the beginning of the larynx) is innervated by what?
the internal branch of the vagus nerve CN X
motor innervation of the muscles of the pharynx is supplied by what? exception?
vagus nerve CN X — except stylopharyngeus = CN IX
the pharynx ends and the oesophagus begins at what level?
C6
identify A,B,C
A = ostium of auditory tube
B = the fold formed where the palatopharyngeus muscle underlies the mucosa
C = laryngopharynx
function of stylopharyngeus
shortens, widens and elevates the pharynx, and elevates the larynx
what is A?
What is B? what originates from the lower end of this?
what is C?
what nerve can be seen crossing A?
A = stylopharyngeus — CN IX can be seen crossing it
B = stylohyoid ligament — middle pharyngeal constrictor originates from lower end of this
C = posterior wall of larynx