Nose & Nasal Cavity

What are the three main regions of the nose

Vestibule, olfactory region, and respiratory region

What is the function of the olfactory region

It mediates the sense of smell

What is the olfactory region of the nose lined with

Mucosa

Through which structure do the axons of olfactory neurons pass

The cribriform plate as the olfactory nerve (CN I)

Name that

Vomeronasal Organ

What is the function of the vomeronasal organ

It detects pheromones used in sociosexual communication

Which nerve relays signals from the vomeronasal organ

The terminal nerve (CN 0)

Where do signals from the vomeronasal organ project to

The hypothalamus

What type of epithelium lines the respiratory region of the nose

Pseudostratified columnar ciliated epithelium with goblet cells

The same epithelium that lines the respiratory portion of the nose also lines a lot of the respiratory system. Which parts of the respiratory system are NOT lined by respiratory epithelium

It lines all of the conducting portion of the respiratory system except the oropharynx & vocal folds (you would need something different for the place you eat & the place you sing in fairness!)

It also lines the paranasal sinuses.

What does the respiratory epithelium produce, and how does its product change

It produces a watery mucus that thickens when dehydrated or inflamed

What are the unpaired bones of the nasal skeleton (medial & lateral walls)

Ethmoid, sphenoid, frontal, and vomer

What are the paired bones of the nasal skeleton (medial & lateral walls)

Nasal, maxillary, palatine, lacrimal, and conchae

Role of turbinates/conchae

They create turbulent airflow to help filter, humidify, and warm the air.

Where does the sphenoid sinus drain

Into the sphenoethmoidal recess

Where do the anterior and middle ethmoidal sinuses drain

Beneath the middle turbinate, into the hiatus semilunaris

Where does the maxillary sinus drain

Beneath the middle turbinate

What opens beneath the inferior turbinate

The nasolacrimal duct open

Which cranial nerve is responsible for the sense of smell

The olfactory nerve (CN I) (@ cribriform plate)

innervation of the medial nasal wall

Arterial supply to the septum

Bottom left corner is Superior labial artery

What’s the green circle where the arteries meet

Kiesselbach's plexus / Little’s area

Arterial supply to the lateral nasal wall

Arterial supply to the lateral nose loves pairs! 4 arteries - 2 sets of pairs

There are 3 bones involved in the naming process - ethmoid, sphenoid, palatine

Venous drainage of the lateral nasal wall

No valves in veins draining head & neck (no need - gravity!!!)

Which artery supplies the middle and inferior turbinates/conchae

The sphenopalatine artery

Which veins drain the lateral nasal wall?

he nasal vein, which drains into the cavernous sinus, pterygoid plexus, and facial vein

Where do 90% of nosebleeds occur

Anterior nose in Little’s area/Kiesselbach’s plexus (arterial)

Which plexus is responsible for posterior nosebleeds

Woodruff’s plexus (venous)