Thorax- nose Flashcards
What is the function of the nose and nasal cavities?
olfaction (smelling)
respiration
filtration of dust
humidification of inspired air
reception and elimination of secretions from nasal mucosa, paranasal sinuses and nasolacrimal ducts
What does the bony part of the nose consist of
nasal bones
frontla process of maxillae
nasal part of frontal bone and nasal spine
bony part of nasal septum
What does the cartilaginous part of the nose consist of
two lateral cartilages
two alar cartilages (U shaped, can move around)
septal cartilage
where do nasal cavities open to?
what lines it?
- Entered through nares open posteriorly to nasopharynx through choanae
- Mucosa lines nasal cavities except the vestibule of nose (skin)
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boundaries of the nasal cavity
- Roof: curved and narrow except at posterior end
- Floor- hard palate
- Medial wall: nasal septum; perpendicular plate of ethmoid, vomer, septal cartilage and nasal crests of maxillary and palatine bones
- Lateral wall: uneven- nasal conchae and meatus
what is the mucosa of nasal cavities continuous with?
all chambers communicating with nasal cavities: nasopharynx (posteriorly), paranasal sinuses (superiorly and laterally), the lacrimal sac and conjunctiva superiorly
what is unique about the olfactory area?
specialised mucosa with peripheral organ of smell, sniffing draws air
- Receptor neurones in olfactory epithelium- forms nerve bundles passing through cribriform plate of ethmoid bone and enters olfactory bulb
what are nasal conchae
curves projecting out of the lateral wall
- inferior, middle and superior
creates meatus for the air to flow
why are meatus’ important in respiration
increases surface area- increases amount of air inspired and come in contact with cavity walls
Slows down air flow and makes it turbulent, humidified and cleaned.
where is the spheno-ethmoidal recess
in superior concha
receives opening of sphenoidal sinus
where is the ethmoidal infundibulum
middle meatus communicates with frontal sinus
where is the Semi-lunar hiatus
openings of frontal, maxillary and anterior ethmoidal sinuses
where does the nasolacrimal duct drain into
inferior meatus (tears in eye)
what is the ethmoidal bulla
bulge in lateral wall formed by middle ethmoidal sinus
what are paranasal sinuses and what do they do
what are they lined with
air filled extensions of respiratory part of nasal cavity
humidifies air, makes the skull weigh lighter
respiratory mucosa
Frontal sinus:
triangular shaped
- Frontalnasal duct-> ethmoidal infundibulum -> semilunaris hiatus -> middle meatus
- CN V1: supra-orbital nerves
Sphenoid sinus
level of spheno-ethmoidal recess
Pituitary gland can be accessed via this sinus.
Thin plates of bone separate from optic nerves, pit. Gland, internal carotid arteries
- Superior meatus
posterior ethmoidal nerves
Ethmoidal sinus:
- Anterio– middle meatus
- Middle– middle (forms ethmoidal bulla)
- Posterior- superior meatus
- CN V1 anterior and posterior ethmoidal branches of nasociliary nerves
- Posterior ethmoidal artery and nerve
Maxillary sinus
- Maxillary ostium -> Semi lunar hiatus -> Middle meatus (cannot drain when head it erect until full)
- Base: inferior part of lateral wall of nasal cavity
- Roof: floor of orbit
- Floor: alveolar part of maxilla
- Maxillary artery, branhes of greater palatine artery
- CV N2: Alveolar nerves
what is most commonly infected?
what issues arise due to the anatomy of this?
maxillary sinus
ostia are high
when the head is vertical it is impossible for the sinuses to drain until they are full
when lying down only the upper sinus of one side drains so there will be rolling at night
what is the role of epiglottis
prevents food from entering trachea due to elevation of hyoid bone
function of uvula
during swallowing it moves superiorly with soft palate to close off the nasopharynx to prevent food entering nasal cavity
gag reflex can be initated via vagus nerve
what bone is this?
hyoid bone
what is the adams apple also known as
laryngeal prominence of thyroid cartilage
function of arytenoid cartilages
attaches to vocal folds to allow movement of vocal chords
what is the hard palate made up of
palatine process of maxilla and palatine bone
what is the choanae
posterior nasal aperture
empties into nasopharynx
what is respiratory epithelium
ciliated psuedostratified columnar epithelium with goblet cells
border of nasopharynx
communicates with nasal cavity anteriorly and soft palate
borders of oropharynx
between soft palate and superior border of epiglottis
laryngopharynx border
between the superior border of the epiglottis and inferior border of the cricoid cartilage C6
opening of auditory (Eustachian) tube
opens into the nasopharynx at the level of the inferior meatus. It allows the middle ear to equalise with the atmospheric air pressure.
function of soft palate
prevents the food bolus from entering the nasopharynx by closing pharyngeal isthmus
what nerve innervates all the sinuses and what type of nerve is it
trigeminal nerve- mixed nerve
sensory nerve supply of nasal cavity
special sensory: olfactory nerves
general: nasopalatine and nasociliary nerves CNV1+2
paranasal sinuses and sinusitis
infection can spread from nasal cavitites to produce inflammation and swelling of mucosa of sinuses as they are continuous
cranial nerves and referred pain
irritation of cranial nerve V can caise referred ear pain
