Anatomy of the Nose and Paranasal Sinuses Flashcards
What are the vital functions of the nose and paranasal sinuses?
- Olfaction
- Provides route for inspired air
- Filtering and humidifying inpsiured air
- Allowing drainage of secretions from paranasal sinuses and nasolarimal ducts
- Resonating chamber for speech
How does the nose remove particles from air?
By trapping in nasal hair and mucous
Why does the nose and nasal cavity need to warm inspired air?
So that is doesn’t irritate the naso- and oropharynx
What is the external nose?
A predominantly cartiaginous structure
What forms the root of the external nose?
The frontal processes of the maxillae and two nasal bones
What is the bridge of the nose?
The junction between bone and cartilage
What is the result of the nose lying in such a prominent position?
It is often involved in injuries to the face
What can injuries to the nose cause?
- Septal deviation
- Nasal bone fractures
- Lots of swelling
What is the result of there being lots of swelling in injuries to the nose?
May not be able to reset the nost immediately
What is it important to consider in a patient with a nasal fracture?
If you have sustained a nasal fracture, you must have sustained a resonable force to the face, and so must consider other injuries, and take a comprehensive history with examination
What fractures in a nasal fracture?
The bone, the cartilaginous part is squashy and moveable, so absorbs some of the force
What is the space between the shelf of the external nose called?
The vestibule
What is the vestibule?
The entrance into the nasal cavity
What is the vestibule lined with?
Skin, with sebaceous glands and hair cells
Where does the nasal cavity extend?
From the nostrils anteriorly (anterior nasal aperture) to posterior nasal aperture
What does the nasal cavity have it terms of borders?
- Roof
- Floor
- Two walls
What is the floor of the nasal cavity made up of?
- Hard palate - maxilla and palatine bone
- Soft palate
What is the medial wall of the nasal cavity?
The nasal septum
What is the nasal septum made up of?
- Septal cartilage
- Perpendicular plate of ethmoid bone
- Vomer bone
Draw a diagram of the nasal septum
What is the lateral wall of the nasal cavity made up of?
Maxilla
What does the lateral wall of the nasal cavity have?
Shelf like bony projections called turbinates
What are the names of the turbinates?
- Superior
- Middle
- Inferior
What is the lateral wall of the nasal cavity covered by?
Respiratory mucosa
What do the turbinates create?
Spaces underneath called meatus
What is the function of the turbinates?
- Slow airflow, so air can be modified
- Increases surface area over which air passes
What does the nasal cavity open into?
The nasopharynx
What does the nasopharynx have an opening into?
The Eustachian tube
What is the significance of the Eustachian tube?
It is in anatomical connection with the middle ear, and so a potential route for the spread of infection
What are the paranasal sinuses?
- Extensions of the nasal cavity
What are the names of the paranasal sinuses?
- Maxillary
- Frontal
- Ethmoidal
- Sphenoid
What is the largest of the paranasal sinuses?
Maxillary
What does the maxillary sinus occupy?
Most of the maxilla bone
What does the ethmoidal sinus collectively consist of?
Anterior, middle, and posterior air cells
Describe the paranasal sinuses at birth
Absent or rudimentary
What are the paranasal sinuses lined with?
Respiratory mucosa;
- Ciliated
- Pseudostratified
- Columnar
- Have goblet cells for mucous secretion
What is the function of the paranasal sinuses?
- Help humidify and warm inspired air
- Reduce weight of the skull
What is the relationship between the nasal cavity and the paranasal sinuses?
They all communicate with the nasal cavity via their respective opennings, and drain into the nasal cavity via small channels called the ostia
What can any obstruction to drainage from the paranasal sinuses lead to?
Accumulation of mucosal secetions and development of infection
What is in important anatomical relation with the paranasal sinuses?
- Orbit
- Anterior cranial fossa
- Roots of upper teeth
How is the orbit in anatomical relations with the paranasal sinuses?
Ethmoidal air cells
Which sinus is the anterior cranial fossa in important anatomical relation with?
Frontal
What do the roots of the upper teeth sometimes project into?
The maxillary sinus
What is the rich blood supply to the nasal mucosa key for?
To allow the warming and humidification of inspired air in nasal cavity
Where is the venonus drainage of the nasal cavity into?
- Cavernous sinus
- Facial veinn
- Pterygoid plexus
What is the blood supply of the antero-superior portion of the nasal cavity and most of the paranasal sinuses via?
Branches of opthalmic artery
What is the nerve of the antero-superior portion of the nasal cavity and most of the paranasal sinuses via?
Opthalmic nerve
What is the blood supply to the postero-inferior portion of the nose via?
Branches of maxillary artery
What is the nerve supply to the postero-inferior portion of the nose via?
Maxillary nerve
What does Waldeyer’s tonsillar ring refer to?
A collection of lymphatic tissue surrounding the superior pharynx
What does Waldeyer’s tonsillar ring consist of?
- Lingual tonsil
- Palatine tonsils
- Tubal tonsils
- Pharyngeal tonsils, or the nasopharynx/adenoid tonsil
Where is the lingual tonsil located?
On the posterior base of the tongue
What does the lingual tonsil form?
The antero-inferior part of the ring
Where are the palatine tonsils located?
On each side between the palatoglossal and glossopharyngeal arches
What are the palatine tonsils?
The common ‘tonsils’ that can be seen within the oral cavity
What do the palatine tonsils form?
Lateral part of the ring
Where are the tubal tonsils located?
Where the Eustachian tube opens into the nasopharynx
What do the tubal tonsils form?
The lateral part of the ring
Where is the pharyngeal tonsil located?
In the roof of the nasopharynx. behind the uvula
What does the pharyngeal tonsil form?
The postero-superior part of the ring
What is the purpose of Waldeyer’s Ring?
Responds to pathogens that may be ingested or inhaled
