Station 3: The Pharynx Flashcards
Where does the pharynx extend from (vertebral levels)?
The base of the skull to vertebral level C6/7 (the level of the junction of the larynx and the trachea)
What are the 3 subdivisions of the pharynx? What does each conduct?
Naso-, Oro-, and Laryngo-pharynx
All three conduct air, the latter 2 also conduct fod
Where does the Eustachian Tube open? Where does it come from? What is its function? What problems can happen with it?
Other names for it?
Opens in nasopharynx.
Comes from the middle ear.
Functions:
Pressure equalization and drains mucous from ear into nasopharynx
Infection can easily spread from nasopharynx to the nasopharynx. Especially in younger children as their eustachian tubes are so thin.
AKA the auditory tube
What is the lymphoid tissue in the pharynx called?
MALT. Mucosa Associated Lymphoid Tissue.
What is a Mucosa?
Mucosas cover epitheliums that are involved in absorption and/or secretion.
Glands in the submucosa secrete mucous onto mucosal surface, and glands in the epithelium (e.g. goblet cells) also secrete mucous. Usually have a ciliated epithelium to move particulate or other matter through the mucous.
What are tonsils? Their finction
Tonsils are non-encapsulated aggregations of lymphocytes.
MALT
Function: Large aggregations can act much the same way as a lymph node in that they can form germinal centres and have discrete B and T cell zones, and mount both humoral and cell mediated responses to antigenic stimulation
Describe the arrangement of the tonsils in the pharynx. What is the name of this arrangement? Which tonsils are involved?
Waldeyer’s Ring
The tonsils form a ‘ring’ of lymphatic tissue aroung the posterior openings of the oral and nasal cavities into the pharynx.
This is part of the MALT
Consists of the palatine, linguinal and pharyngeal tonsils.
Describe the number of, the epithelium of, number of crypts, and the location of the Palatine Tonsils
2 of them
Stratified Squamous
10-20 Crypts
Located between the palatoglossal and palatopharyngeal arches
Linguinal tonsil(s): Number of, epithelium, crypts, location
Numerous linguinal tonsils
Stratified Squamous
1 crypt
On surface of posterior 1/3 of th tongue
Pharyngeal tonsil(s): number of, epithelium, crypts, location
1 of them
Respiratory Epithelium
Have folds which may resemble Crypts
Located in the roof of the nasopharynx
What are the functions of tonsilar crypts?
Crypts are crevasses in the tonsils. They reach through almost the full thickness of the tonsil. Functionally, they massively increase the surface area of the tonsils, maximising its immune function - greater contact between environmental influences and the lymphoid tissue
Look at the tonsil slides
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