Pharynx-Wilson Flashcards
What is the pharynx?
The pharynx is a fibro-muscular tube that extends from the base of the skull to the beginning of the esophagus at cervical level C6. -best view is the saggital view -long tube of mostly muscles and surrounded by fascia
What are the general functions of the pharynx?
1) Upper end of digestive system (tube for eating); -part of the digestive system (connecting oral cavity with esophagus) -swallowing has 3 phases: grinding food up and mixing it with saliva ; you take your tongue and push food back to your pharynx 2) Upper end of respiratory system (tube for breathing); if you have a cold you can’t breathe through your nose but you can breathe through your mouth. You have the POTENTIAL OF CHOKING of food due to the dual function of pharynx for eating and breathing. 3) First line of lymphatic defense against infectious invasion into respiratory and digestive system
HUMANS HAVE AN ELONGATED PHARYNX NECESSARY FOR SPEECH
the position of the pharynx changes with evolution : descends and elongates -it’s important to get the pharynx in the neck for speech production -this has a cost though which is the potential for choking Because of the development of the oropharynx, humans are uniquely prone to choking
Because of its length we divide it into 3 parts
The Pharynx is Divided into 3 Regions: dictated by what is found anterior to the structure Nasopharynx -1 part behind the nasal cavity Oropharynx - 2 directly behind the oral cavity Laryngeal -3 directly behind the larynx
Anterior Boundaries of Pharynx
Nasopharynx Posterior Choanae -once you go through the choana you are in the nasopharynx Oropharynx Palatoglossal Arch -the innervation of the pharynx; when you are anterior to this arch you are in the oropharynx; once food is transferred after this arch you stimulate CN IX which will???; stimulate gag reflex behind this arch ????
SENSORY INNERVATION
upper part of nasopharynx is innervated by V2 (pharyngeal branch) lower part of oropharnx is CN X everything below the epiglottis is innervated by CN X vagus nerve in terms of its composition is primarily PS; fibers transferred to mucosa lining the laryngeal pharynx
The Right & Left Palatoglossal Folds Form an Arch That Separates Oral Cavity From Oropharynx
a mucous fold is a muscle of the same name (Palatoglossal muscle)??? -anterior to the arch is the V2 -behind the arch is CN IX; activate the involuntary phase of swallowing and gag reflex
Touching Posterior to the Palatoglossal Arch Evokes the Gag Reflex
everything behind uvula will initiate a gag reflex
GAG REFLEX
-you can observe . the elevation of the soft palate -it is a symmetrical appearance
Vagal nerve damage (motor limb)
touch in the oropharynx -flaccid paralysis of the muscle of the soft palate -lack of elevation of the soft palate -uvula deviation towards the normal side
The Muscles of the Pharynx Are Derived From the 4th Pharyngeal Arch
esophagus is skeletal muscle ??? They are Organized Into 2 Groups: 1) outer circular (3 muscles) 2) inner longitudinal (3 muscles)
outer circular (3 muscles)
-called constrictors Superior Pharyngeal Constrictor -originates from pterygomandibular raphe that goes from the pterygoid plate to the mandible; there is a muscle anterior to this raphe called buccinator Middle Pharyngeal Constrictor -originates from hyoid bone Inferior Pharyngeal Constrictor -originates from larynx; attaches to thyroid and cricoid cartilage through these gaps structures can come and go from outside of the pharynx to inside of the pharynx Has a 4th technically
cricopharyngeus muscle
does not have a separate origin or any fascia surrounding it making it different -anatomically speaking is part of the constrictors; it is the most inferior part; the inferior fibers of the inferior constrictor are called the “cricopharyngeus muscle” cricopharyngeus -tonically constricted; this muscle is under contraction all the time because we’re breathing -prevents air from entering stomach during breathing -relaxes during swallowing; has to relax to allow food to transfer from pharynx to esophagus
During Swallowing, Constrictors Produce a Peristaltic Wave
-tongue pushes food up against hard palate and pushes it back -once food passes the fold CN IX is triggered -goes all the way to the esophagus with constrictors squeezing or milking the food ????
The conically shaped constrictor muscles overlap so that the lower muscle constricts around the bolus and the muscle above.
As you swallow food, as the food is being squeezed from one constructor to another. There is a period of transition. The muscle contract at the same time for food to go down ?????This prevents the bolus from being squeezed out laterally during swallowing. Theoretical: If the timing of contraction of the muscle are not the same food can go in either direction: -food in the neck instead of the esophagus
Pharyngo-Esophageal (Zenker’s ) Diverticulum : the real
During swallowing peristaltic wave produce a lot of pressure to push food down to esophagus. If you have a weakened wall of pharynx, this food instead of going to the esophagus will form a diverticulum that makes the food go to the neck. clinical consequences: -puch gets larger and larger blocking the esophagus making swallowing much more difficult (dysphasia) -through swallowing this the tissues around the pouch is elastic and so when you’re swallowing there will ???squeeze food back to the laryngeal pharynx resulting in regurgitation of food -halitosis: funky breath Diagnosis: -Deglutition = Swallowing -Dysphagia = Swallowing Dysfunction -have patient to swallow water and hear the water gurgling down (time how long it takes) -10 second lag may indicated dysphagia Treatment: staple the pouch and remove the food
3 longitudinal muscles functions
-shorten the length of pharynx to reduce probability that food will go into esophagus instead of respiratory system -when they contract they expand the pharynx laterally
3 longitudinal muscles
- Salpingopharyngeus: -attaches to the eustachian tube and is innervated by CN X 2. Palatopharyngeus CN X another fold or arch that is in the oropharynx entirely and goes from soft palate to pharynx 3. Stylopharyngeus CN IX goes between the superior and middle constrictor; innvervated by CN IX (third pharngeal arch) ???
Smooth muscles of soft palate
-uvula -levator veli palatini: elevates the soft palate during swallowing -tensor veli palatini: deeper and more anterior; ????bony projection coming off the lateral pterygoid plate; around this bone is where the muscle makes a 90 degree turn and attaches to the soft palate: innervated by CN V3; pulls the palate laterally -pterygoid hamulus ??????? palatoglossus : serves as the boundary btw oral cavity and oropharynx palatopharyngeus?????
Vagus nerve innervation of the soft palate
-cell bodies of vagus nerve is found in the nucleus ambiguus (closed medulla) along the reticular formation SVE fibers of CN X originate from nucleus ambiguus open medulla=inferior olivary complex spinothalamic tract: pain/temp/touch stroke in lateral part of the medulla would result in ???? NA location is important in determiing in whether the stroke is medial or lateral medulla.
What is the most important structure in the nasopharynx?
auditory tube: -the opening; is not flat but has a mucosal ridge around it called torus tubarius -salpingo- pharyngeal fold nucleus fold that extends from auditory tube to pharynx -???gap is the pharyngeal recess
Auditory tube
-The auditory tube connects the middle ear and nasopharynx -It permits air pressure in the middle ear cavity to equalize to atmospheric pressure, ie. ventilates the middle ear cavity. Atm pressure is always changes and can make the TM to bulge inwardly or outwardly. When pressure is equal TM is in neutral position which maximizes hearing. -It provides a pathway for infection to spread from nasopharynx to the middle ear through the euchastian tube (auditory); otitis media
The auditory tube opens during swallowing
-most often closed -really only opened when you swallow The auditory tube opens during swallowing (note: attachment of muscles to the pharyngeal tube) tensor veli palatini and salpingopharyngeus muscles are attached to the auditory tube which opens the lumen of the tube when muscles contracts
PHARYNGEAL TONSILS
serves as the first line of lymphatic invasion of bacteria into upper parts of digestion and respiratory system Pharyngeal Tonsil Tubal Tonsils: surround the auditory tube they are loose aggregates of LT or nodules; they not encapsulated to a distinct structure swelling of throat lead to fullness in ear because of blockage of air leading into the oral cavity ?????? Adenoids as they get larger will prevent mouth breathing. ?????
ADENOID FACIES
1) chronic mouth breather 2) dull, dimwitted appearance 3) drying of gingivae (mucosa around oral cavity), leading to gingivitis the tongue is important for the development of dental arches aligning the hard palate and teeth well ????
SOFT PALATE
-A moveable, muscular septum -sometimes it hangs down or laterally
During swallowing, soft palate swings posteriorly & superiorly
-to seal off the nasopharynx from the oropharynx -produces a partition that separates the nasopharynx and oropharynx -due to this partition food only has one way to go which is towards the esophagus
Paralysis of the soft palate
-soft palate fails to form a partition due to vagal nerve lesion??? -results in a regurgitation of food into the nasal cavity during swallowing
Neurotoxins produced by Corynebacterium Diphtheriae may result in paralysis of the soft palate
-Neurotoxins kill nerve endings of the vagal nerve
UVULAR PARALYSIS
Uvula is drawn to the opposite side of the lesion when the patient says, “A-AH”
During sucking, it swings anteriorly & inferiorly to seal off the oral cavity from the oropharynx
-not posteriorly like in swallowing -forms a seal with the back of the tongue -you expand the size of the oral cavity?????? -when a baby suckles they can breath at the same time???? the pathway for respiration remains open making breathing possible during sucking A vacuum is produced by expanding the volume of a sealed oral cavity
PALATINE TONSIL
The palatine tonsil is located between the palato-glossal & -pharnygeal folds. CN V2or V3 before palato-glossal CN IX behind
Surface Anatomy of the Palatine Tonsil
tonsillar crypts: trap foreign material: but because they are isolated they be a reservoir bacteria intratonsillar flect derived from the pharyngeal pouch??? peritonsillar abscess: oropharynx is being blocked posteriorly makes swallowing and breathing difficult
Acute Follicular Tonsillitis
Advanced stage: Acute Streptococcal Pharyngitis The infected tissues act as a reservoir of bacteria
Tonsil Stones (Tonsillolith)
-largely asymptomatic -bad breath
TONSILECTOMY
-usually performed between ages 3-5 -take a spoon with very sharp edges and take out the tonsils
Blood Supply to Tonsillar Bed
1) MAJOR BRANCH tonsillar artery** (facial) 2) ascending palatine (facial) 3) descending palatine (maxillary) 4) ascending pharyngeal (external carotid) 5) dorsal lingual (lingual) There are at five arteries supplying the tonsillar bed. When you scoop the tonsil you can get bleeding. But this is not the problem The external palatine vein is usually the source of serious hemorrhage. The vein is low pressure and collapses on itself. If the vein hasn’t clotted to control bleeding. -Make sure to give child icecream due to the cold slowing down the bleeding
A tortuous internal carotid artery may lie immediately outside the tonsillar bed.
-ICA with a tortuous course -this artery has high pressure and will squirt out blood profusely
Complications of tonsillectomy
CN IX Crosses the Tonsillar Bed -CN IX is vulnerable in tonsillectomy either from direct trauma or tissue edema -CN IX responsible for gag reflex, swallowing but also has taste fibers
Jugulodigastric Nodes: Tonsillar Nodes
-in the junction between internal jugular vein and posterior digastric -Palpation of Cervical Lymph Nodes -if these nodes become larger and larger they can swell to the point where they block bleeding
TONSILLAR RING
First line of lymphatic defense against infectious invasion into respiratory and digestive system -tubal tonsil -palatine tonsil -lingual tonsil -pharyngeal tonsil (adenoids) ????
SLEEP APNEA
Definition: abnormal pauses in breathing that may last a few seconds to several minutes. Types: 1. obstructive: 84% 2. central (rhythm generator in medulla are not working properly) 3. mixed (obstructive & central): 15%
Causes of obstructive sleep apnea:
-narrowing of air-passageway -obesity -microstoma -enlarged tonsils -enlarged tongue -airway infection (tonsillitis) -smoking -alcohol use -diabetes
Effects of Sleep Apnea
- hypoxia & hypercapnia -stroke -brain degeneration (mammillary bodies which are involved in short term memory) -cardiovascular disease arrhythmias hypertension 2. sleep deprivation - fatigue -accidents -depression & irritability -learning & memory 3. sexual dysfunction
CNS Systems of the Brain Affected
- Executive functions 2. Attention 3. Memory/learning
PIRIFORM RECESS
cul-de sacs found on either side of the pharynx ????? -diverts food laterally so food will divert into the recess ????\ During swallowing, the pharynx is elevated allowing the piriform recess to expand laterally to its maximal extent. The bolus of food flows as two streams through the piriform recesses.
This site is most often where foreign material becomes lodged in the throat.
The piriform recess is often the site where foreign material becomes lodged in the throat
NErves lies deep to the ????
Extraction of foreign material from the piriform recess may damage the: 1. internal laryngeal nerve -recurrent laryngeal nerve ?????
The Retropharyngeal Space (behind pharynx) Extends From the Base of the Skull and Into the Thorax
Infections, that enter the retropharyngeal space, can produce an abscess that obstructs swallowing (dysphagia) and/or breathing. Infections may also enter the thorax producing mediastinitis ?????
The pharynx is a fibro-muscular tube that extends from the _____________ to the beginning of the esophagus at _______________.
base of the skull; cervical level C6
First line of lymphatic defense against infectious invasion
Pharynx
Because of the development of the oropharynx, humans
are uniquely prone to ____________.
choking
•The upper part of the nasopharynx is innervated by the pharyngeal branch of V2, which comes off the _________________.
pterygopalatine ganglion
•The oropharynx is innervated by ___________, that region is important because of the gag reflex.
CN IX
•The laryngeal pharynx receives sensory innervation from ________.
CN X.
The Right & Left __________ Form an Arch That Separates Oral Cavity From Oropharynx
Palatoglossal Folds
Touching Posterior to the ____________ Evokes the Gag Reflex.
Palatoglossal Arch
The front of the epiglottis is innervated by the ____________.
trigeminal
The Muscles of the Pharynx Are Derived From the _________Pharyngeal Arch
They are Organized
Into 2 Groups:
1) outer circular (3 muscles)
2) inner longitudinal (3 muscles)
4th
Superior Pharyngeal Constrictor
(originates from __________)
Middle Pharyngeal Constrictor
(originates from __________)
Inferior Pharyngeal Constrictor
(originates from __________)
pterygomandibular raphe
hyoid bone
larynx
The inferior fibers of the inferior constrictor are called the ______________.
“cricopharyngeus muscle”
The fibers of the cricopharyngeus are special because they are tonically constrictive, except during swallowing.
- This prevents air from entering stomach as lungs expand. You change pressure during breathing
- This muscle relaxes while swallowing
Sometimes food goes out laterally. It is called the _______________. Short term is called Zenker’s.
pharyngo-esophageal diverticulum (out-pouching)
- Symptoms of Zenker’s is halitosis (bad breath), food regurgitates up throat.
LONGITUDINAL MUSCLES of Pharynx
- Salpingopharyngeus-CN X
- Palatopharyngeus- CN X
- Stylopharyngeus- CN IX
*elevate pharynx & larynx (during swallowing & talking)
Muscles of the soft palate
- tensor veli palatini
- levator veli palatini
•Nucleus ambiguous innervated muscles from the _______, ______, and ________ arches
3rd; 4th; 6th
Around the opening of the auditory tube, it is elevated, which forms the __________.
torus tubarius
- The torus tubarius extends posteriorly and forms the salpingopharyngeal fold. 1/3 muscles that elevates the pharynx while swallowing is the salpingopharyngeal.
- There is a deep recess called the pharyngeal recess
• The __________ separates the middle ear cavity and the external acoustic meatus
tympanic membrane
The body wants to make sure that the air pressure in middle ear cavity equals the external auditory meatus, so tympanic membrane is in neutral position. Elevate pressure externally, the tympanic membrane bulges __________( internally/externally). If there is pressure in the middle ear cavity the tympanic membrane blow up to a balloon ,___________ (externally/ internally).
Internally; externally
Adenoids:
•pharyngeal tonsil that is enlarged.
ADENOID FACIES
1) chronic mouth breather
2) dull, dimwitted appearance
3) drying of gingivae, leading to gingivitis
Anterior to the Eustachian tube is ___________. Behind the tensor veli palantini is the________.
tensor veli palatine; levator veli palantini
QUINSY
PERITONSILAR ABSCESS
- Abscess is pressing tonsil in oral cavity.
- An abscess surrounding tonsils (peritonsillar abscess) it is unilateral
- But it can spread bilaterally, both tonsils pushed together and then you can suffocate
Surface Anatomy of the Palatine Tonsil
- Surface of tonsils are pitted. They have fingerlike diverticulum (tonsillar crypts). In the middle of tonsils, have intra-tonsillar cleft (remnants of 2nd pharyngeal pouch)
- You can get bacteria and food collecting in cleft by not getting flushed out. You get abscess forming which can spread to deep part of tonsils producing a peritonsillar abscess, an abscess that surrounds outside of tonsil.
Blood Supply to Tonsillar Bed
1) tonsillar artery**
(facial)
2) ascending palatine (facial)
3) descending palatine (maxillary)
4) ascending pharyngeal (external carotid)
5) dorsal lingual
(lingual)
In tonsillectomy, the ____________ is usually the source of serious hemorrhage.
external palatine vein
What are complications of a tonsillectomy?
- Bleeding (particular external palatine vein)
- Cutting CN 9
- Tonsillectomy patients say that food doesn’t taste well because the nerve fibers need to regenerate
Lymph nodes travel along internal jugular vein. The lymph nodes are called the ______________, a specific node is jugular digastric node or upper deep cervical node.
deep cervical lymph nodes
The ___________ is often the site where foreign material becomes lodged in the throat.
piriform recess
Extraction of foreign material from the piriform recess may damage the:
1) internal laryngeal nerve
