Pharynx Flashcards
How can the pharyx be divided into 3 sections and state the vertebral height of each
- Nasopharynx: 1 vertebral height (C1)
- Oropharynx: 2 vertebral heights (C2-3)
- Laryngopharynx (Hypopharynx): 3 vertebral heights (4-6)
What 2 structures comprise the nasopharynx?
Adenoids and Eustachian tube orifices
Where is the pharynx and where does it extend from and to?
A Musculofascial tube that is progressively longer and narrower from top to bottom and Incomplete anteriorly
It extends from the base of skull to oesophagus (C6) and is the common entrance to GI and respiratory tracts
Label the 3 sections of the pharynx
Give the boundries of the nasopharynx
Superior: skull base and sphenoid sinus
Inferior: soft palate and continuous below with oropharynx
Anterior: choanae of nasal cavities
Posterior: Body of C1
What type of epithelium lines the nasopharynx
Both respiratory type and stratified squamous epithelium
When does the pharynx open and close?
TRICK QUESTION… ALWAYS OPEN
What tonsils are found in the nasopharynx
Describe this
Nasopharyngeal Tonsil (Adenoids)
This is a collection of lymphoid tissue beneath posterior roof epithelium which produces IgA, IgG, IgM
(This along with palatine tonsils helps to form → Waldeyer’s Ring)
What elevation on the side wall is an opening connecting nasopharynx with middle ear?
Obstruction can lead to what?
Pharyngotympanic Tube (Eustachian Tube) Orifice
Obstruction can lead to “Glue Ear”
When is the max size of our adenoids reached and then what occurs?
Give another example of where these may enlarge
Maximal size 3-8 years (then regress)
Enlargement with viral/bacterial infections
Where is the oropharynx located and give its boundries
Behind oral cavity and tongue
Boundaries:
- Superior – level of soft palate
- Inferior – superior edge of epiglottis
- Anterior – oral cavity
- Posterior – C2 – C3
What epithelium lines the oropharynx?
Stratified squamous epithelium
What marks the boundary between the oral cavity and oropharynx
Palatoglossal folds (arches)
Give the contents of the oropharynx
Describe the structure, epithelium and muscles involved in these structures
1) Palatine tonsils are (encapsulated)
2) Anterior and posterior tonsillar (faucial) pillars
The tonsillar fossa floor is formed by the superior constrictor muscle. The lymphoid tissue is covered with squamous epithelium and there are many crypts found here.
Label the palantine arches
What tends to occur to the tonsils as we age
Atrophies after puberty
Where are the Palatine tonsils located?
Lie in tonsillar fossae (between ant. and post. pillars)
The Anterior pillar is also known as what arch?
Describe this
Palatoglossal arch:
- Boundary between buccal cavity and oropharynx
- Fuses with lateral wall of tongue
- Contains palatoglossal muscle
The Posterior pillar is also known as what arch?
Describe this
Palatopharyngeal arch
- Blends with wall of pharynx
- Contains palatopharyngeus muscle
What is the blood supply to the Palatine tonsils?
Tonsillar branch of facial artery (branch of ECA)
Also lingual/ ascending palantine/ ascending pharyngeal BUT tonsilar is the main
What is the venous drainage of the Palatine tonsils?
pharyngeal plexus (also paratonsillar vein)
What structure must we be carful of when removing the tonsils or draining a quinsy?
We must be carful of the ICA because this runs in close proximity
Describe the lymph drainage of the Palatine Tonsils
Lymphatics pierce superior constrictor muscle ➞
Pass to nodes along internal jugular vein ➞ Jugulodigastric node (angle of mandible)
What node is indicated by the arrow and what 3 structures does it drain?
Jugulo-digastric: drains tonsil, pharynx, posterior tongue
What 2 structures is the piriform fossa located between and what is its function?
Recess between the central layrnx and lateral thyroid cartilage (in the laryngopharynx)
Functions to channel solids/liquids from oral cavity around raised laryngeal inlet INTO oesophagus
What is the largest part of the pharynx and below what structure is this located?
Laryngopharynx (Hypopharynx) located below epiglottis
Give the boundries of the Laryngopharynx
Superior – superior edge of epiglottis
Inferior – level of inferior edge of cricoid cartilage
Anterior – larynx
Posterior – C3 – C6 vertebrae
What is the laryngopharynx continuous with inferiorly?
The oesophagus
What epithelium lines the laryngopharynx?
Stratified squamous epithelium
What are the 2 main muscles groups of the pharynx and how are they arranged?
There are 2 layers of muscle which supply the pharynx:
- Inside we have longitudinal
- Outside we have have constrictor muscles
What are the 3 constrictor muscles of the pharynx?
- Superior Constrictor
- Middle Constrictor
- Inferior Constrictor
The 3 constrictor muscles _____ each other and are located Immediately anterior to the _________
They open _______ to nasal, buccal and _______and are attached posteriorly by the _______
They sequentially contract to propel food down the _______
overlap, prevertebral fascia, anteriorly, laryngeal cavities, median raphe, oesophagus
Label the 3 contrictor muscles + other addition impt muscle
Which contrictor muscle forms the floor of the tonsilar fossa?
Superior Constrictor
What are the 3 stages of swallowing?
Oral (voluntary)
Pharyngeal (involuntary/reflex)
Oesophageal (involuntary/reflex)
What is the function or the oral phase?
What occurs during this phase?
Lubrication and formation of food bolus by mastication
- Tongue pushes bolus to back
- Oesophageal sphincter contracted
- (Epiglottis raised)
What occurs during the pharyngeal phase?
1) Soft palate raised (nasopharynx closed off and eustachian tube opens)
2) Hyoid and Larynx raised
3) Epiglottis down and Tongue blocks off mouth
4) Sequential contraction of constrictors moves bolus into hypopharynx
6) Oesophageal sphincter relaxed
What 3 muscles raise the Hyoid and Larynx during the pharyngeal phase
Action of tongue, longitudinal pharyngeal muscles and suprahyoid muscles
What protects the larynx during the pharyngeal phase of swallowing?
Overhanging tongue, Epiglottis, Vocal cords
When the nasopharynx closes why does our eustachian tube open?
To equalise pressure!
What separates the nasopharynx from the oropharynx during swallowing?
Elevation of soft palate + constriction of the palatopharyngeal sphincter
This is why food doesn’t go up our nose when we swallow!!
What happens with the Oropharynx AFTER chewing?
1) When holding food in mouth: oropharynx is sealed off
2) Opens for swallowing → THEN Oropharyngeal opening CLOSES
3) Laryngeal cavity is CLOSED
4) Food is directed towards oesophagus
Can we breathe and swallow at the same time and why?
You CANNOT breathe and swallow at same time because airway is closed at 2 sites → the pharyngeal opening and the larynx
What occurs during the oesophageal phase?
1) Epiglottis up
2) Hyoid and Larynx down
3) Oesophageal sphincter (cricopharyngeus) contracted
4) Peristalsis moves bolus to stomach
What anatomical considerations must be made for swallowing and breathing
Pathway of breathing shown by yellow line
Pathway of swallowing is red line
There is overlap!! Hence we must consider where things may go wrong here… Eg. after a stroke we can get swallowing difficulties which can lead to aspiration pneumonia
Also in aesthetics we MUST protect the airways from anything going down airway (NBM)
What is the sensory supply to each of the 3 sections of the pharynx?
Nasopharynx – Maxillary division of Trigeminal (V2)
Oropharynx – Glossopharyngeal (IX)
Layrngopharynx – (X)
What is the motor supply to muscles of the pharynx?
All pharynx muscles = Vagus (X)
EXCEPT:
- Stylopharyngeus - Glossopharyngeal (IX)
- Tongue - Hypoglossal (XII)
- Stylohyoid - Facial (VII)
What is the blood supply to the pharynx
Superior Thyroid and Ascending Pharyngeal
*Both branches off ECA
What is the venous drainage of the pharynx?
Pharyngeal venous plexus → Drains into IJV
Label this X-ray
A.epiglottis
B. hyoid
C.laryngeal vestibule
D.cricoid
E.trachea
F.Cx6
