Nose/Sinuses Flashcards
What is the primary nasal function?
As an airway is respiration
Who is the primary nasal function particularly important in?
Neonates who are obligate nasal breathers
What type of cells are present in the sinonasal mucosa?
Respiratory ciliated columnar epithelium with goblet cells
What other nasal functions are there?
- Warming of inspired air
- Humidification
- Filtration of large particulate matter by coarse hairs (vibrissae) in the nasal vestibule
- Mucus production, trapping and ciliary clearance of particulate matter
- Immune protection
- Olfaction
- Drainage/aeration of the middle ear via Eustachian tube
- Drainage of paranasal sinuses and nasolacrimal duct
- Voice modification
What role does the nasal passages play in voice modification of animals?
Pheromone detection via the vomero-nasal organ of Jacobson
What is thought to be the function of the sinuses?
- Help with vocal resonance
- Decrease the weight of skull and facial bones
- Act as buffer for trauma
Name the parts of the external nose.
- Glabella
- Nasion
- Dorsum
- Supratip
- Tip
- Collimnella
What are the 2 components of the external nose?
- 1/3 bony
- 2/3 cartilage
What is the external nose formed from?
Frontal processe of maxilla and nasal part of frontal bones
What is the clinical relevance of the external nose?
- Deformities that can be congenital or acquired
- Acquired almost always due to trauma
What are the boundaries of the internal nose?
Midline partition to nasal septum
What forms the lateral walls of the internal nose?
Turbinates
What forms the roof of the internal nose?
Cribriform plate
What forms the floor of the internal nose?
Hard palate
What are the associated structures of the internal nose?
- Paranasal sinuses
- Nasopharynx
What is the clinical relevance of the internal nose?
- Deviation (Congenital or acquired. Acquired almost always caused by trauma)
- Septal perforation
- Septal haematoma
Turbinates
Bony scroll like projections from lateral wall of nose
What are the 3 types of turbinates?
- Superior
- Middle
- Inferior
What is each turbinate associated with?
Its respective meatus
What is the clinical relevance of the turbinates?
Usually inferior turbinate only
-Can cause nasal blockage due to inflammation or infection
How can nasal blockage due to the turbinate be manages?
- Medically with topical steroid
- Surgically with turbinate reduction surgery
What are the different types of paranasal sinuses?
- Frontal
- Maxillary x2
- Ethmoid (anterior and posterior)
- Sphenoid
What does the inferior meatus drain?
Nasolacrimal duct
What does the middle meatus drain?
- Frontal
- Maxillary
- Anterior ethmoid
What does the superior meatus drain?
- Posterior ethmoid
- Sphenoid
Rhino sinusitis
Reflects a concurrent inflammatory and infective process that affects the nasal passageway and contiguous para nasal sinuses
What are the 2 classifications of rhino sinusitis?
- Acute (bacterial)
- Chronic (lasts more than 12 weeks)
What are the 2 classifications of chronic rhino sinusitis?
- With polyps
- Without polyps
What is the important relation of the frontal and ethmoid sinuses?
Anterior cranial fossa
What are the important relation of the maxillary sinus?
Orbits
What are the important relations of the sphenoid sinuses?
- Optic nerve
- Internal carotid artery
- Cavernous sinus
Why are the relations of the sinuses of clinical importance?
Spread of infection
- Meningitis
- Intracranial abscess
- Orbital sepsis
Risk of surgery
- CSF leak
- Orbital complications possibly leading to blindness
How is the nasal blood supply broadly divided?
- Anterior
- Posterior
What is the anterior nasal blood supply?
- Derived from branches of the internal carotid artery
- Ophthalmic artery branching into anterior and posterior ethmoid arteries
What is the posterior nasal blood supply?
- Derived from branches of external carotid artery
- Sphenopalatine artery
What is the clinical relevance of Little’s area?
-Epistaxis most commonly occurs in Little’s area
What are common causes of epistaxis?
- Trauma including nose picking
- Anticoagulants
- Iatrogenic
- Idiopathic
- Hypertension
What are the important nerves of the nasal passages?
- Most come from trigeminal cranial nerve
- Greater and lesser palatine nerves stem from the facial nerve
What is the clinical relevance of the nerves of the nose?
Olfactory dysfunction due to rhino sinusitis, post viral anosmia and trauma
