Nasal Cavity Flashcards
What are the functions of the respiratory system?
- warm, humidify and filter inhaled air
- olfaction
- help produce sound
- provide O2 and remove CO2
- helps maintain acid-base balance
- protective and reflexive non-breathing air movements (cough/sneeze)
- assist circulation of blood and lymph towards heart
- help abdo muscles during defecation, parturition, lifting a heavy object to function effectively
What is included in the upper respiratory tract?
- nose (nasal cavity)
- nasopharynx
What is included in the lower respiratory tract?
- larynx
- trachea
- bronchial tree
- alveolar ducts
- pulmonary alveoli
- alveolar sac
What forms the medial wall of the nasal cavity?
- bone: vomer and ethmoid posteriorly
- cartilage anteriorly
What forms the roof of the nasal cavity?
bones:
- nasal
- frontal
- ethmoid
- sphenoid
What forms the floor of the nasal cavity?
- palatine bones
- maxilla
- hard and soft palates
What is an important feature of the hard palate?
- it is horizontal
- clinical application: insertion of nasogastric tube
Where would you find nasal conchae (turbinates)?
projecting from the lateral wall and forming meatuses
What is the function of the muscles around the nostrils?
- act as sphincters or dilators
- control the diameter of nares and adjust air flow
What are the muscles around the nostrils?
- procerus
- nasalis
- levator labii superioris alaeque nasi
What are the function of conchae?
- increase surface area
- form air channels (meatuses) where paranasal sinuses and the nasolacrimal duct open into
What are the gateways of the nasal cavity?
- foramen caecum (between nasal veins and superior sagittal sinus)
- cribiform plate
- sphenopalatine foramen
- incisive canal (2 way passage)
Where does the olfactory nerve pass through?
cribiform plate
What vessels pass through the sphenopalatine foramen?
- sphenopalatine artery (maxillary a.)
- nasopalatine nerve (maxillary n.)
- superior nasal branches of maxillary nerve
What vessels pass through the incisive canal?
- nasopalatine nerve (from nasal to oral)
- terminal end of greater palatine artery (from oral to nasal)
What vessels pass through the small foramina in the lateral wall of the nasal cavity?
inferior nasal branches of greater palatine nerve (maxillary a.)
List the paranasal sinuses?
- frontal sinuses
- sphenoid sinus
- ethmoidal cells
- maxillary sinuses
What lines the paranasal sinuses?
ciliated and mucous secreting respiratory mucosa
Where does the frontal sinus drain mucus to?
- through frontonasal duct to ethmoidal infundibulum
- part of middle meatus of nasal cavity
Where does the maxillary sinus drain mucus to?
middle meatus of nasal cavity
Where does the ethmoid sinus drain mucus to?
- middle ethmoid sinus: bulla ethmoidalis on middle meatus
- anterior ethmoid sinus: ethmoidal infundibulum on middle meatus
- posterior ethmoid sinus: superior meatus
Where does the sphenoid sinus drain mucus to?
- through the spheno-ethmoidal recess to the superior meatus of the nasal cavity
Where does the nasolacrimal duct drain mucus to?
inferior meatus
Describe the vascular supply of the nasal cavity
- terminal branches of maxillary and facial arteries (branch of external carotid a.)
- ethmoidal branches of opthalmic artery (branch of internal carotid a.)
- anastomose between internal and external carotid a.
