Flashcards in Lecture 28 RH Deck (53):
What is the bony part of the nose made up of?
bony part of the nose is mostly formed by frontal process of the maxilla and the rest is formed by nasal bones.
What structures form the walls of the nose?
nose is split in 2 halves with lateral and alar cartilages forming the walls of the nose. The middle is made up of septal cartilage.
What are the anterior nares?
anterior nares = nostrils.
What structures form the nasal septum?
septum is formed anteriorly by septal cartilage and posteriorly is contributed to by the vomer. Superiorly part of the ethmoid bone to the nasal septum.
Where is the etmoid bone located relative to the nasal cavity?
superiorly to the nasal cavity
Where is the ethmoid located within the head?
anterior cranial fossa
What is present at the posterior aspect of the nasal cavity superiorly?
posteriorly and superiorly to the palatine bone the body of the sphenoid bone is present.
Where is the posterior nare located?
Between the medial and lateral side of nasal cavity posteriorly under the sphenoid bone is an opening called the posterior nare.
What bone can be found directly posteriorly in the nasal cavity?
The palatine bone
What is the superior projection of the superior aspect of the ethmoid bone?
The projection is the crista gali and it projects from the cribiform plate.
What bones can be found laterally within the nasal cavity?
lateral wall contains alar cartilage, lateral cartilage, maxilla with the frontal projection and the ethmoid bone with its lateral projections.
lacrimal bone posteriorly related to the orbit.
What is the function of sinuses?
sinuses are their to decrease weight at the front of the head.
To assist phonation by allowing sound to resonate within them.
What are the functions of the nasal cavities?
Forms resonating cavity for voice
Has olfactory receptors to sense odors
it is the upper part of the respiratory tract
What is the functions of the hairs found within the anterior nare?
hairs prevent foreign material from entering the nose
What is the result of the arrangement of the bones in the nasal cavity like when looking at it in the coronal plane?
When looked at in the coronal plane the nasal cavity has the appearance of an 'M'
Where is the cribiform plate located?
cribiform plate is located in the anterior cranial fossa and is a flat bone with many holes. It is part of the ethmoid bone.
What is the result of bad breaks in the nose?
bad breaks of nose could damage the cribiform plate causing infection, bleeds and rhinorrhea which can spread to the meninges and the brain which are located right above it.
What is rhinorrhea?
rhinorrhea is leakage of CSF through the nose.
Why does the cribiform plate contain so many holes?
The olfactory nerve runs above the cribiform plate and forms a bulb right next to the crista gali on both sides. Filaments go through the cribiform plate's holes and act as receptors for smell which send messages to the brain.
What lines the medial wall of the nasal cavity?
The highly vascular mucous (this took a conscious effort to not yankify) membrane.
What is the function of the highly vascular mucous membrane?
The mucous membrane warms and moistens air up prior to entering the lower airway.
Why must air be warmed up prior to entering the lower respiratory system?
Cold air makes smooth muscle spasm. This is why asthmatics have a problem with bronchiole spasms.
What is the material that lines the nasal cavity mucosa?
Most of nasal mucosa is composed of ciliated pseudostratified columna epithelium.
Where can cilia be found in the respiratory system?
Cells that line most of the nasal cavity and in fact the inferior 2/3rds and continue down into the airways are ciliated.
What is the function of the cilia?
Cilia are hair-like projections and they beat in a direction towards the front of the nasal cavity. They move mucous to the front of the nasal cavity.
What happens to the lower airways of smokers?
Smoking damages cilia in the nasal cavity and so mucous builds up in the lower airways of smokers overnight.
What is the vestibule and what does it contain?
Vestibule is the entrance point of the nostril. It is lined by skin and hair
How many conchae can be found in each nasal cavity?
3 conchae: Superior, middle, and inferior
What do conchae do?
Conchae are lined by highly vascular epithelium and they cause air turbulence to keep it within nasal cavity prior to being breathed in as a method to warm it up closer to body temperature.
What are the spaces underneath the conchae called?
meati (superior, middle, and inferior)
What do the openings of the superior and middle meati open into?
The paranasal sinuses
What are paranasal sinuses?
Paranasal sinuses are opening in bones that develop as outpouchings from lateral wall of nasal cavity. As it opens up it drags with it the mucosa of the nasal cavity and that lines these spaces.
What are the paranasal sinuses that are located on top of the nasal cavity?
What are paranasal sinuses named after?
after bones that they sit in
What sinuses are located laterally to the nasal cavity?
Maxillary sinus sits in the cheek laterally in the body of the maxilla.
What is the problem with sinus innervation?
Bacteria can migrate into sinuses and create infection which is very painful due to the innervation of these sinuses.
What are the nerves that innervate the sinuses?
C5 (trigeminal nerve) splits into an opthalmic, maxillary, and mandibular divisions.
What nerve innervates the frontal, ethmoid, and sphenoid sinuses?
Level of the eye by opthalmic division.
What nerve innervates the maxillary sinus?
maxillary sinus from superior alveolar nerves which branch from maxillary division of the trigeminal nerve.
What is the clinical significance of the proximity of the maxillary sinus to the root of the molars?
Maxillary sinus is near the roots of the molars when molars are 'yanked out' they could cause fracture of the maxillary sinus and infection could result.
What is the clinical significance of the direction of the pathway from the nasal cavity to the sinuses?
Ethmoid and sphenoid sinuses are less prone to infection than the maxillary sinus due to the location of the openings to the sinuses. The ethmoid and sphenoid require bacteria to work against gravity and these sinuses are easily drained. whereas the maxillary is pretty high and the path is downwards from the nasal cavity.
Where are the openings in the meati relative to the sinuses?
openings of the superior and middle meati are located right next to the location of the sinuses.
Where is the opening of the sphenoid sinus located?
sphenoethmoidal recess which is a space between the sphenoid and the ethmoid bone.
What does the superior nasal meatus contain besides the openings for the sphenoid sinuses?
The rest of the superior meatus has openings in it for the posterior part of the ethmoidal sinuses.
What is the functional significance of the hiatus semilunaris?
Hiatus semilunaris is a crescent shaped groove in the middle meatus associated with a swelling called the bulla ethmoidalis.
The hiatus semilunaris and bulla ethmoidalis are landmarks because at the front end of the hiatus semilunaris we have openings for the frontal sinus and also the very anterior ethmoidal sinuses.
The posterior end of the hiatus semilunaris forms an opening for the maxillary sinus and because they are higher the sinuses are located lower opening upwards
The middle of the hiatus semilunaris contains an opening to the middle ethmoidal cells
What opening is contained in the inferior meatus?
The inferior meatus contains the opening to the nasolacrimal duct which comes from the lacrimal sac in the medial aspect of the orbit
What arteries and veins supply the anterior part of the nasal cavity?
Medially: Little branches from the facial artery.
Laterally: Little branches from the labial arteries which mainly supply the lip
Veins of the same name drain the anterior portion of the nasal cavity.
What arteries and veins supply the posterior quadrant of the nasal cavity?
sphenopalatine artery which originates from the internal carotid artery
What arteries and veins supply the superior quadrant of the nasal cavity?
ethmoidal arteries which arise from the opthalmic arteries which arrives from the orbit
Which blood vessel is the biggest contributor to the blood supply of the nasal cavity?
the sphenopalatine artery.
What arteries and veins supply the inferior quadrant of the nasal cavity?
Branches of the greater palatine artery supply the inferior nasal cavity and the palatine bone.
What is characteristic of nasal blood supply?
There are lots of anastomoses