Nasal Cavities and Paranasal Sinuses

what are nasal cavities

they are a pyramidal shaped space, divided into two equal halves by the nasal septum. They are open at anterior and posterior ends

what separates the nasal cavities

the nasal septum separates them into 2 equal halves

what does the pharynx sit behind

it sits behind the nasal and oral cavities

what divides the nasal and oral cavity

a hard palate divides it

what is the part of the pharynx behind the nasal cavity called

its called the nasopharynx

what is the part of the pharynx behind the oral cavity called

its called the oropharynx

what does the soft palate do

it helps navigate food and air into their respective tubes

what is the part of the pharynx behind the larynx called

its called the laryngopharynx

what are conchae

they are 3 curved bony projections from lateral walls of each cavity, creating channels between them

what is another name for conchae

they are also called turbinates

what are meatuses

they are channels between cavities

what are choanae

they are the posterior openings of nasal cavities into nasopharynx

what are nares

the nostrils, external openings that allows the nasal cavity to communicate with the external environment

what is the function of the hard palate

it is the floor of the nasal cavity and the roof of the oral cavity

what is the lateral wall divided into

it is divided into the superior, middle and inferior concha

what are the spaces under the superior, middle, and inferior concha

they are the superior, middle, and inferior meatus

what are the superior and middle concha part of

they are part of the ethmoid bone

What wall of the nasal cavity do the lacrimal and nasal bone make

they make the superior/anterior part of the lateral wall

What wall of the nasal cavity do the maxilla and palatine make

they make the floor (hard palate) and lateral wall

What wall of the nasal cavity do the vomer and ethmoid make

they make the roof and medial wall (ethmoid also lateral wall)

What wall of the nasal cavity does the sphenoid make

it makes the roof and posterior lateral wall (medial pterygoid plate)

What wall of the nasal cavity does the frontal bone make

It makes the roof (anterior)

what concha are in the lateral wall

the superior and middle concha

what is a key contributor to the nasal cavities

the ethmoid bone is

what is the medial pterygoid plate a part of

it is part of the sphenoid bone along with the lateral pterygoid plate

where is the sphenoethmoidal recess

it is above the superior concha

what bones create the septum

the ethmoid and vomer create it

where is the crista Galli

it is on top of the ethmoid

what do the 3 conchae create

they create 3 meatuses that cannel air through nasal cavity from nares to choanae

what do the conchae act as

they act as baffles, restraining the flow of air to warm and humidify it (increased surface area of mucosa)

what are the 3 conchae

the superior, middle, and inferior nasal concha

what are the 3 meatuses

the superior, middle, and inferior meatus

what are all inside surfaces of the nasal cavity lined with

all inside surfaces are lined with mucosa

what is the function of mucosa

its function is to warm, humidify and filter the air

what does the pharyngotympanic tube connect, what does it allow

it connects the nasopharynx and the middle ear, allowing pressure to be equalized on both sides of the tympanic membrane

what are the paranasal sinuses

they are 4 paired air filled spaces lined with mucosa connected medially to nasal cavities

what do the paranasal sinuses grow within

they grow within frontal maxillary sphenoid and ethmoid bones

what are the functions of the paranasal sinuses

immune (mucosa/mucus)

warming/humidifying air

altering/amplifying voice?

scaling skull size appropriately as we grow, while keeping it light

what are the paranasal sinuses connected to

they are all connected to the nasal cavity

what do the frontal, maxillary, and ethmoid sinuses drain into

they drain into the middle meatus, for frontal sinus its via the frontal nasal duct

what else does the ethmoid sinus drain into

it also drains into the superior meatus

what does the sphenoid sinus drain into

it drains into the sphenoethmoidal recess

what can mucus accumulation from sinuses enter

they can enter the nasal cavity, then into the nasopharynx via choanae

what happens when infectious air enters the sinuses

it causes sinusitis, in the maxillary sinus this can cause referred pain to the upper teeth via maxillary nerve V2 branches

what is the parasympathetic innervation of the lacrimal gland

it is CN VII and will cause tears

where does the lacrimal gland sit

it sits in the lacrimal fossa

what do nasolacrimal duct drain into

it drains into the nasal cavity in inferior meatus, under the inferior nasal concha

what does the masolacrimal duct lead to

it leads to the nasal cavity

where is the lacrimal sac

it sits in fossa between lacrimal and maxilla bones

what are the lacrimal puncta

they are openings

where does blood supply to all the organs and regions of the head come from

it comes from the carotid arteries with contributions from the vertebral arteries to the brain

where does the carotid system begin

it begins as the common carotid (early branch of aorta) rising superiorly in the neck and bifurcating at the level of C4/C5 into the internal and external carotid arteries

where does the internal carotid artery enter the cranial cavity

it enters the cranial cavity via the carotid canal and foramen lacerum

what does the internal carotid artery give off

it gives off large branches to the orbit and eye (ophthalmic artery)

what do most of the branches of the internal carotid artery supply

they mostly supply blood to the brain

what is the external carotid after the main blood supply for

it is the main blood supply to the structures of the neck, face, scalp, and oral and nasal cavities

what does the sphenopalatine artery enter the lateral posterior nasal cavity through

it enters the lateral posterior nasal cavity through the sphenopalatin foramen

where does the superficial temporal artery go to

it goes to the scalp

where does the occipital artery go to

it goes to the posterior scalp

where does the facial artery go to

it goes to the face

where does the lingual artery go to

it goes to the tongue and oral cavity

what is the maxillary artery

it is the terminal branch of the external carotid artery

what are the two terminal branches of the external carotid artery

the maxillary artery and the superficial temporal artery

where does the maxillary artery travel

it passes medial to the mandible, where it gives branches to the oral cavity

which terminal branch of the maxillary artery enters the nasal cavity at the sphenopalatine foramen

the sphenopalatine artery with enter at the sphenopalatine foramen

where does arterial supply to the nasal cavity come from

it mainly comes from the sphenopalatine artery (nasal and septal branches) and from the ethmoidal arteris and branches of the ophthalmic artery

where is the ophthalmic artery from

it is from the internal carotid

what is general sensory innervation to the nasal cavities like

it is split between branches of the ophthalmic nerve and maxillary nerve

where are the olfactory nerves

they pass through the cribriform plate and provide olfaction innervation only

what is the anterior ethmoid nerve a branch of

it is a branch of the nasociliary nerve from V1

where does the anterior ethmoid nerve travel

it goes to anterior medial and lateral walls of nasal cavity, including septal cartilage

where does the nasopalatine nerve run

it runs along the vomer and septum (medial wall) and also enters the oral cavity via incisor foramen to palate

what are nasal nerves branches of

they are branches of the maxillary nerve (V2) to posterior lateral and medial walls including the septal cartilage as the nasopalatine nerve

what causes the nasal cavity to be deviated to one side or the other

it can be a result of a birth injury but more often occurs during adolescence and adulthood from trauma

what happens if the nasal septum deviation is too severe

if it is too severe and contacts the lateral wall of the nasal cavity, it can obstruct breathing of exacerbate snoring, it can be corrected surgically