Station 1 Flashcards
Which bones form the boundaries of the anterior opening of the nasal cavity?
Inferiorly: Palatine process of maxilla
Superiorly: Nasal Bone
What are the functions of the turbinates and meatuses?
Collectively, the arrangement of the turbinates and meatuses serve to provide lamiar flow of air through the nasal cavity, and to increase surface area of the respiratory epithelium.
The largest (inferior) turbinate is responsible for most of the directing of flow, heating and humidification of inspired air before it progresses into the naso-, oro-, and laryngopharynx, to the trachea.
Functions:
Directing flow
Heating air
Humidifying air
Trapping inhaled particles in mucous of respiratory epithelium (immunological)
Provide the humidification needed to keep the delicate olfactory epithelium healthy
What are the two bones that form the most of the skeleton of the nasal septum
Vomer and Perpendicular plate of the ethmoid bone. (the rest of the septum is completed, anteriorly, by cartilage)
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What bone forms most of the roof of the nasal cavity? What goes through the small foramina in the roof?
Ethmoid Bone.
Olfactory Nerves pass through the Olfactory Foramina in the cribriform plate of the ethmoid bone
What are the two bones of the hard palate? What is the functional significance of the hard palate?
Palatine Process of the Maxilla
Horizontal Plate of the Palatine Bone
It separates the nasal and oral cavities
Which bones make up the lateral wall of the nasal cavity?
Maxilla, Palatine, Ethmoid (as sup and mid turbinates), the Inferior Turbinate (independent bone), the Lacrimal bone, Nasal bone
List the bones that form the margins of the choanae
Choanae = opening into the nasopharynx from the nasal cavity
Anteriorly/Inferiorly: Horizontal plate of the palatine bone
Superiorly/Posteriorly by the Sphenoid
Which bones contain the paranasal sinuses?
Frontal (frontal sinus), Ethmoid (Ethmoid Air Cells), Sphenoid (Sphenoid Sinus), Maxilla (Maxillary Sinus).
Where do each of the air sinuses open into the nasal cavity?
Sphenoid opens onto the sphenoethmoidal recess posteriorly to the superior turbinate
Frontal opens via the nasofrontal duct into the semilunar hiatus of the middle meatus
Maxillary sinus into the semilunar hiatus of the middle meatus
Ethmoid air cells open into the middle and superior meatus
Where do tears from the eye enter the nasal cavity?
Via the nasolacrimal duct, onto the inferior meatus
What is the problem with the maxilalry sinus’ drainage?
The opening of the maxillary sinus at the superior end of the sinus, thus does not drain well in the upright position. Drains bettwe when lying on one side.
E.g. lying on left side drains the right maxillary sinus
Things to recognise on the foetal head
Tongue, Mouth, Developing teeth, eyes, hard palate, nasal cavity, nasal septum, brain
What type of epithelium lines the majority of the nasal cavity?
Respiratory epithelium.
Pseudostratified ciliated columnar epithelium with mucous secreting goblet cells. Other cells present include granule cells (endocrine functions), brush cells (chemo- and general sensory), and basal cells (stem cells)
Function of paranasal air sinuses?
Debatable.
Theories include:
Reducing weight of facial bones,
Increasing vocal resonance,
Reducing blunt pressure during blows to the face,
Increasing surface area available to humidify inspired air (due to slow turnover of air in this region),
Immunological function
What type of epithelium lines paranasal sinuses?
Respiratory Epithelium
