BIOL 208 Lecture Notes - Lecture 11: Adenoid, Otitis Media, Middle Ear
Anatomical structures of respiratory pathway
● pharynx is involved in respiratory and digestive system
● 3 divisions of pharynx; nasopharynx, oropharynx, laryngopharynx
nasopharynx
● has hard palate, soft palate
● uvula as well
● several openings;
● the posterior nasal aperture - allows opening to get into nasopharynx
● external nares - nostril opening. allows air to come in
● internal nares - allows air to leave and get into nasopharynx
● auditory tube/eustachian tube - connects middle tube to pharynx. allows for air to equilibrate.
if you ascend or descend rapidly. have sphincters in nasopharynx that open and allow air in
mouth to exchange in air with ear, otherwise eardrum would pop out.
● with children, especially in first few years of life, the sphincters here are not fully
developed at all. those auditory rubes remain open. when baby has sore throat, then
all of a sudden an ear ache, that is the reason. those little bacteria have control and
they just kind of rest in the ear. this is how babies will have frequent middle ear
infections. even though throat infection isn't severe, once you get to middle ear can
be bad. this is because sphincter isn't developed yet.
tonsils
***an aggregated mass of lymph nodules and associated lymph vessels found in various regions of
the pharyngeal mucosa***
● basically involved in immune process but these can sometimes become overwhelmed with
bacteria and stuff they become inflamed and can’t do their job so they get removed
● first type is found in nasopharynx known as the pharyngeal tonsil. this is a single tonsil and
has another name, the adenoids
● found right in back wall of nasopharynx
● this word adenoids means “like a gland” basically (adeno means gland, oid means like) but
its more of an immune structure. picks up and captures bacteria and microorganisms that
helps in destroying them and sometimes they become inflamed themselves
● at the very base, almost marking the line of demarcation between nasopharynx and
oropharynx, is the uvula. have hard palate, tissue, soft palate. end of soft palate marks upper
limit of oropharynx or lower limit of nasopharynx. a function is when you swallow, it goes
backwards and blocks fluids from getting out to nostrils
Oropharynx
● basically a tube in back of nose, back of mouth, goes down until it comes to “fork in the road”
which would be either go continue to esophagus to continue into trachea
Oropharynx
● as you open your mouth and look straight back into the back of your throat, go beyond that
have back wall. thats part of the oropharynx, that region behind your mouth
● that opening, space that goes from mouth that transcends, is the transitionary area to
oropharynx called the fauces
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***the fauces is that airway region that connects the oral cavity with the oropharynx***
● the fauces, the airway proceeding from mouth to oropharynx, transitionary area, is bound by
2 arches;
● 1) palatoglossal arch - connected to palate. closer to tongue
● 2) palatopharyngeal arch - behind palatoglossal arch. closer to pharynx. further back
● fauces represents transitional area
● space running through, throughway of area is faces
● fauces takes you to oropharynx
● 2nd set of tonsils found here between these 2 arches is called the palatine tonsil. on either
side of mouth. between 2 arches on way to oral cavity to the oropharynx
● 3rd kind of tonsil is lingual tonsil. further down. located at the base of the tongue
● if tonsils do their job properly, placed strategically. when food is coming in got some in
nasopharynx for any kind of airborne materials coming through nose that need to be taken
out, also have the palatine tonsils and the lingual tonsils
Larygopharynx
● basically extends from where the hyoid bone is
● goes down until where you come to where the larynx and esophagus part ways. and the
pharynx continues to allow air to get into lungs or allow food to go into the esophagus
Larynx
● called the voice box
● serves as beginning for entrance for respiratory system
● has 9 cartilages in total. 8 are made up of hyaline cartilage, 1 made up of elastic cartilage
(we will discuss the 4 main relevant ones)
● 1) thyroid cartilage - the biggest one. very large. when some people have adams apple,
thyroid cartilage of voice box that does this. adams apple is the laryngeal prominence. so
thyroid cartilage is a whole cartilage but anterior portion that sticks out a bit is known as the
laryngeal prominence
● 2) epiglottis cartilage - its connected to the thyroid cartilage. hovers over the opening of the
thyroid cartilage. opening as air continues from laryngopharynx into the airway, the larynx.
that space is called the glottis. the epiglottis is the name of the cartilage. it is elastic cartilage.
serves as like a half open top. as soon as you swallow it comes down and covers opening of
larynx, and food continues down esophagus. usually not an issue but once in a while food
will get lodged in there and if small can cough it out, if large need some sort of heimlich to
get it out. it is elastic cartilage and its attached to the thyroid cartilage by a “stem”
● 3) cricoid cartilage - lower most of the cartilage. forms most of rear section of the larynx.
larynx has thyroid cartilage in front, cricoid cartilage in the back. forms front and back. this is
the cartilage that makes contact with first of tracheal cartilages. trachea is a whole series of
cartilages that are semicircular and thats what keeps airway open. continues into bronchi
then starts disappearing
● 4) arytenoid cartilages - these are paired. right behind this has arytenoid muscles (intrinsic
muscles). these are paired, meaning that there are 2 of them. these arytenoid cartilages are
basically resting on the top of the cricoid cartilage. so cricked cartilage serves as the last of
the laryngeal cartilages as that rests on the tracheal cartilages, but above it is the arytenoid
cartilage. significance of the arytenoid cartilage is they are connected to the vocal
cords/vocal folds, as well as the arytenoid muscles. these muscles are voluntary. the
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Document Summary
Pharynx is involved in respiratory and digestive system. 3 divisions of pharynx; nasopharynx, oropharynx, laryngopharynx nasopharynx the posterior nasal aperture - allows opening to get into nasopharynx. External nares - nostril opening. allows air to come in. ***an aggregated mass of lymph nodules and associated lymph vessels found in various regions of the pharyngeal mucosa*** Basically a tube in back of nose, back of mouth, goes down until it comes to fork in the road which would be either go continue to esophagus to continue into trachea. ***the fauces is that airway region that connects the oral cavity with the oropharynx*** the fauces, the airway proceeding from mouth to oropharynx, transitionary area, is bound by. 1) palatoglossal arch - connected to palate. closer to tongue. 2) palatopharyngeal arch - behind palatoglossal arch. closer to pharynx. further back. Space running through, throughway of area is faces.
