UNIT 6: Pharynx + Glossopharyngeal CN Flashcards
the pharynx is a _______ tube, ____ cm long, and extends from _____ to ______
vertical musculo-membranous tube
12 cm long
extends from base of skull @ C6 posteriorly to cricoid cartilage anteriorly
pharynx is continuous with
nasal cavity anteriorly
oral cavity anteriorly
larynx anteriorly
esophagus inferiorly
musculo-membranous tube is composed of (4 parts - superficial to deep)
mucous membrane
fibrous coat - pharyngobasilar fascia
muscular coat
buccopharyngeal fascia
the muscular coat of the pharynx is… (2 parts)…. what do they do?
muscles that run horizontally, wrapping around from front to a midline raphe in the back
in swallowing these construct the pharynx, helping push the food thru its length; also participate in velopharyngeal closure (soft palate to PPW)
AND muscles that run inferiorly from the skull - shorten the length of the pharynx by pulling superiorly
3 functions of the pharynx
acts as a resonating chamber for speech; alters spectral characteristics of sound
contracts during swallowing, clearing the food bolus from the pharynx into the esophagus (provides common pathway for food intake and breathing)
forms the upper esophageal sphincter (UES)
sensory innervation to the pharynx is provided by
CN IX and pharyngeal branch of CN X
pharynx can be divided into 3 parts
nasopharynx
oropharynx
laryngopharynx
what are the boundaries of the nasopharynx
superior = skull base (sphenoid)
inferior = level of palate
posterior = pharyngeal protuberance in basioccipital portion of occipital bone
_____ keeps the nasopharynx open, and runs from ….
pharyngobasilar fascia (fibrous coat) - runs from base of skull superiorly; inferiorly becomes thinner and disappears
the nasopharynx is lined with
ciliated epithelium which have cilia that beat in opp direct to the cilia in trachea
______ is the anterior boundary where nasopharynx communicates with nasal cavity
nasal choanae
the ____ has its opening into the lateral nasopharynx
eustachian tube
superior and posterior edges of ET opening are _____ and covered with ______, and form thickened elevations called the ____, which are formed by _____ and ______
cartilaginous
mucous mem
torsu tubaris
salpinogopharyngeal fold and salpingopalatine fold
pharyngeal tonsils are the _____, which is
adenoids
mass lymphoid tissue located on posterior-superior wall of nasopharynx
boundaries of the oropharynx
superior = level of the palate
inferior = level of hyoid bone
anterior boundary of oropharynx communicates with _____
oral cavity
passavant’s pad is
muscular bulge on posterior oropharyngeal wall; contributes to velopharyngeal closure
faucial pillars separate the ____ from the oropharynx, space bw them houses the _____
oral cavity
palatine tonsils
lingual tonsils are located
on base of tongue
boundaries of laryngopharynx
superior = level of hyoid bone (upper edge of epiglottis)
inferior = C6/level of cricoid (pharyngoesophageal junction)
anterior = epiglottis
laryngopahrynx communicates with ____and ____, and becomes thinner at ______ end
larynx and esophagus
inferior end
3 constrictor muscles of the pharynx
superior, middle, inferior
describe the 3 constrictor muscles of the pharynx
stacked like cups
surround the pharynx and contract during swallowing
each muscle has 2 halves
all are open anteriorly, except lower fibres of inferior constrictor m which form a complete ring
superior constrictor muscle: O, I, A, Inn
O = ptrygomandibular ligament, spehnoid, medial pterygoud plate, hamular process
I = posterior median pharyngeal raphe, pharyngeal tubercle at base of skull
A = forms sides/back wall of nasopharynx and part of back wall of oropharynx - constricts pharynx (in swallowing and velopharyngeal closure)
Inn = pharyngeal branch of CN X (pharyngeal plexus)
middle constrictor muscle: O, I, A, Inn
O = stylohyoid lig, hyoid bone
I = posterior median pharyngeal raphe
A = constricts pharynx
Inn = pharyngeal branch of CN x (pharyngeal plexus)
2 parts of inferior constrictor muscle
thyropharyngeus
cricopharyngeus
inferior constrictor muscle, thyropharyngeus: O, I, A, Inn
O= oblique line of thyroid cartilage
I = posterior median pharyngeal raphe
A = constricts pharynx
Inn = pharyngeal branch of X (pharyngeal plexus)
inferior constrictor muscle, cricopharyngeus: O, I, A, Inn
O = cricoid cartilage
I = other side of cricoid cartilage
A= keeps esophagus closed at UES at rest
Inn = pharyngeal branch, eSLN and RLN of X
3 muscles that elevate the pharynx during swallowing
salpingopharyngeus
palatopharyngeus
stylopharyngeus
salpingopharyngeus: O, I, A, Inn
O = eustachian tube, posterior lip of torus tubaris (salpinogopharyngeal fold)
I = lateral wall of pharynx (w palatopharyngeus m)
A = elevates pharynx, shortens pharynx
Inn = Pharyngeal branch of CN X (pharyngeal plexus)
palatopharyngeus m: O, I, A, Inn
O = palatine raphe (aponeurosis)
I = posterior border of thyroid cartilage, inferior portion of pharynx
A = lifts the pharynx and larynx, directs the bolus into pharynx during swallowing
Inn = pharyngeal branch of CN X (pharyngeal plexus)
palatopharyngeus muscle forms
the palatopharyngeal arch
stylopharyngeus: O, I, A, Inn
O = temporal bone, styloid process
I = (internal) lateral wall of pharynx, thyroid cartilage of larynx
A = elevates larynx and pharynx, shortens pharynx
Inn = CN XI
3 tendons/ligaments of the pharynx
posterior median pharyngeal raphe
pterygomandibular ligament
stylohyoid ligament
posterior median pharyngeal raphe
midline tendon of a pharyngeal aponeurosis
originates at occipital bone and descends along posterior wall of pharynx
site insertion for pharyngeal constrictor muscles
pterygomandibular ligament
extends from hamular process of medial pterygoid plate (of sphenoid) to the mylohyoid line of mandible
stylohyoid ligament
extends from styloid process to lesser cornu of hyoid bone
5 fibre types in CN IX
SVE
GVE
GSA
GVA
SVA
SVE of CN IX supply
the stylopharyngeus muscle (3rd branchial arch)
GVE of CN IX supplies
secretomotor innervation to the parotid gland
GSA of CN IX supplies
posterior 1/3 of tongue, faucial pillars, palatine tonsils, pharyngeal walls, skin of external ear, tympanic membrane (internal surface)
GVA of CN IX supplies
baroreceptors (blood pressure) in the carotid sinus
SVA of CN IX supplies
chemoreceptors (oxygenation) in carotid bodies
taste from posterior 1/3 of tongue
SVE of IX: Intracranial pathway
cell bodies of LMN in nucleus ambiguus (motor nucleus of IX and X) in medilla
axons exits skill via jugular foramen (along w X)
SVE of IX: extracranial pathway
descends w/i neck deep to styloid process and then innervates stylopharyngeus
GVE of IX: Intracranial pathway
Cell bodies in inferior salivatory nucleus of medulla
axons exit skull via jugular foramen w other fibres of IX
GVE of IX: extracranial pathway
supplies secretomotor fibres to parotid gland
GSA of IX are important for
gag reflex and swallowing
Xph and SLN of X also participate in triggering swallowing
GSA of IX: pathway
cell bodies of 1st order sensory nerves are in the inferior glossopharyngeal ganglion
some nerves synapse in spinal tract nucleus (V), some synapse in the nucleus tractus solitarius
______ and _______ are thought to be the most effective sites for triggering the pharyngeal stage of swallowing
anterior and posterior faucial arches
posterior faucial arch, lateral and posterior pharyngeal walls, receive inn from both ____ and ____ and are very densely innervated
IX and X
GVA of IX: pathway
sensations are relayed from the carotid sinus, cell bodies in the inferior glossopharyngeal ganglion
synapse in the nucleus tractus solitariys
connections made w hypothalamus for control of respiration, blood pressure, and cardiac output
SVA of IX: Pathway
cell bodies of 1st order neurons are in the inferior glossopharyngeal ganglion
enter medulla and synapse in nucleus tractus solitarius including the gustatory nucleus
to test the integrity of IX and X, test the _____
gag reflex
how to test the gag reflex of IX and X
mechanical stimulus to the 1/3 of the tongue, palate, palatal arch, posterior pharyngeal wall
see musculature contract when elicited
if no reaction question integrity
to further test the integrity of X observe the
soft palate at rest and on phonation
If a X LMNL, on phonation, will see elevation on intact side of soft palate only, w the deviation of uvula toward the intact side
the pharynx is a multi-purpose musculomembranous tube that ….
in speech acts as a resonating chamber
in swallowing transports the bolus from the oral cavity to the esophagus
the glossopharyngeal nerve holds great importance for respiration bc
it can override motor output based on oxygen needs
the glosspharyngeal nerve is v important for swallowing bc
saliva flow during mastication
sensory input to faciliatate the pharyngeal phase of swallowing
taste from posterior 1/3 of tongue
pharyngeal and laryngeal elevation
