14/15. Paranasal Sinuses + Nose

Question 1

List the 4 functions of nose and 3 functions of the sinuses

Answer 1

1. Breathing
2. Warms/Humidifies Air
3. Filters particulates
4. Olfaction

Sinuses: Vocal resonance, defense against pathogens, reduces weight of head

Question 2

What are the 3 components of the nasal septum

What is the cause and tx of septal hematoma?

Answer 2

1. Perpendicular plate of ethmoid bone
2. Vomer
3. Quadrangular Cartilage

Septal Hematoma: due to trauma, tx by drainage to prevent cutting off blood supply to septum (may cause infection/septal perforation)

Question 3

What are the names of the 3 nasal turbinates? What are their functions?

Answer 3

Superior/Middle Turbinate from Ethmoid
Inferior Turbinate is own bone

1. Increase mucosal surface area
2. Direct Outflow
3. Dynamic: venous sinusoids - nasal cycle - control congestion/airflow
4. Sensation of nasal airflow

Question 4

Olfactory Anatomy
What is the olfactory bulb? Where are the olfactory sensory nerves located? What are common etiologies of Olfactory Loss? How to test olfaction?

Answer 4

Bulb: collection of olfactory nerve cell bodies
Olfactory Sensory Nerves: bodies in epithelium outside bulb and send axons to nerve cell bodies in bulb, life span 6-8 weeks and able to regenerate

Loss: Head trauma (shears olfactory nerves); Viral; Sinonasal (CRS with Nasal Polyps - obstructive vs. sensorineural loss)

Testing: UPSIT (U Penn smell inventory test): IDENTIFICATION of smells - NOT threshold test
Smell better in W > M; olfaction declines after age 60, smoking causes increased olfaction dysfx

Question 5

Describe the Nasal Arterial Blood Supply. Where is the most common place for Epistaxis? How do you treat Epistaxis?

Answer 5

1. Int. Carotid = Opthalmic Artery = Ant/Post Ethmoid Arteries
2. Ext. Carotid = Internal Maxillary Artery = Sphenopalatine Artery

“Little’s Area” where all 3 arteries converge in mid-anterior nose

Tx: Pressure (stop bleeding), Cauterization, Ligation, or Embolization (ONLY Sphenopalatine Artery, b/c don’t want to touch opthalmic arteries!!)

Question 6

Nasal Obstruction: what are the causes?

Answer 6

Nasal Septum Deviation
Nasal Valve Obstruction: at front of nose, greatest area of air resistance (changes air flow from laminar to turbulent to help with mixing/warming), ex: enlarged inf turbinates

Question 7

What are all of the names of the sinuses? Where are they located (boundaries)?

Answer 7

Maxillary Sinus: lateral to nasal cavity = ostium (opening) of mucus at TOP of sinus (against gravity); roof of sinus = orbit floor (maxilla); floor of sinus = teeth roots

Ethmoid Sinus: medial and above nasal cavity, drains posteriorly, many air cells, divided into Anterior and Posterior parts; lateral boundary: orbit (ethmoid); roof = ant cranial fossa; medial border = cribiform plate

Sphenoid Sinus: posterior to ethmoid sinus; lateral to it run the cavernous sinus with carotid a., optic n. CN 3,4,5,6.

Frontal Sinus: into frontal bone, complex drainage, veins to it are valveless - infections can spread hear to orbit

Question 8

What are the functions of mucociliary flow? Where do each of the sinuses drain their mucous within the nasal cavity?

Answer 8

Fx: Humidify and filter inspired air, driven by cilia, not gravity
Drain below middle turbinate: Frontal, Ant Ethmoid, Maxillary Sinuses
Drain above middle turbinate: Post Ethmoid
Drain in Sphenoethmoidal recess: Sphenoid Sinus
Drain below inf turbinate: Nasolacrimal duct

Question 9

Rhinitis vs. Sinusitis

Answer 9

Rhinitis: inflammation of nasal cavity
Sinusitis: inflammation of paranasal cavities

Question 10

What are the 4 big groups of RS sx?

What is the pathophysiology of RS?

Answer 10

1. Nasal Blockage (Congestion/stuffiness)
2. Increased Nasal Discharge (PND)
3. Facial Pain/Pressure/Headache
4. Reduction/Loss of Smell

Virus = Inflammation = edema = ostial obstruction = breeding ground for bacterial infection, hypoxia = ciliary dysfx = secretion stasis = more inflammation = edema = more obstruction etc. (its a cycle)

Question 11

Acute RS (ARS)
What are the 2 main types?
What are the predominant etiologies of each type? 
How are symptoms similar or different?

Answer 11

Viral RS - 50% Rhinovirus, 10-15% Coronavirus, RSV, Adenovirus, Influenza, Parainfluenza
Early Sx: Fever, headache, nasal obstruction
Persistent Sx: cough, nasal discharge
Sx: present for <10 days and do NOT get worse
MAJORITY OF URIs/ARS are VIRAL

Acute Bacterial RS - rare complication of post-viral sinusitis
clinical sign: sx of viral URI WORSEN after 5-7 days
sx: <4 weeks of purulent nasal drainage, with nasal obstruction +/- facial pain
#1: S. pneumoniae
#2: H. influenza
#3: M. catarrhalis

Question 12

Chronic Rhinosinusitis (CRS)
What are defining symptoms of CRS?
What are the 2 phenotypic types of CRS? How are these types different?

Answer 12

Sx: 12+ weeks of 2 or more of big four (nasal drainage, obstruction, facial pressure, decreased olfaction) AND 1+ signs of DOCUMENTED inflammation (purulent mucus/edema in middle meatus, polyps, imaging showing inflammation)

1. Without Nasal Polyps: focal swelling of sinuses causing stuffiness, pain/pressure, mucus, with frequent exacerbations (may be infections)
2. With Nasal Polyps: Less nasal airway space = stuffiness, decreased olfaction (less infections/facial pain)

Question 13

What is the pathophysiology of CRS?

How is CRS treated? How to treat Acute Bacterial Exacerbations? Allergic Components? Acute RS?

What is the goal of surgery for CRS?

Answer 13

Path: any combo of factors creating persistent state of inflammation in nose

Tx: Saline lavage (effective once obstructions relieved - post-surgery), Corticosteriods (topical sprays, never systemic due to SEs)
Acute Bacterial = ABx
Allergies = Antihistamines
Acute RS episodes = decongestant (beware rebound rhinitis if overused)

Surgery goal: improve quality of life! (not curative) - helps improve access of intranasal meds to sinus mucosa (if blocked)