Sinus & Orbits Info Flashcards
What are sinuses?
Air-containing cavities
What are air-containing cavities called?
Sinuses
Whats another name for sinuses?
Paranasal sinuses
Where are the sinuses usually situated?
- Frontal bone
- Ethmoid bone
- Sphenoid bone
- Maxillary bone
What are sinuses formed from?
Nasal mucosa
What do the sinuses communicate with?
Nasal fossas
What does the nasal mucosa form?
Paranasal sinuses
What do the nasal fossas communicate with?
Paranasal sinuses
What are the functions of the sinus?
- Serves as a resonating chamber for the voice
- Decrease weight of the skull by containing air
- Help to warm and moisten inhaled air
- Act as shock absorbers in trauma
- Can possibly control the immune system
When does sinus development start?
Early in fetal life
When do the maxillary sinuses develop?
At birth
When do the frontal sinuses develop?
Around age 6 or 7
When do the ethmoid sinuses develop?
During puberty
When do the sphenoid sinuses develop?
Around age 6 or 7
When are all sinuses completely developed?
By age 17 or 18
Which sinuses develop during puberty?
Ethmoid sinuses
Which sinuses are developed around age 6 or 7?
Frontal and sphenoid sinuses
Which sinuses are evident at birth?
Maxillary sinuses
What starts early in the fetal life?
Sinus development
How many maxillary sinuses are there?
2
How many Frontal sinuses do we have?
1-2
How many ethmoid sinuses do we have?
Many
How many sphenoid sinuses do we have?
1-2
Which sinus is sometimes absent?
Frontal sinus
Which sinus is the largest paranasal sinus?
Maxillary
What shape is the maxillary sinus?
Pyramid
How many walls does the maxillary sinus have?
Three thin walls
Maxillary sinuses vary considerable in ________ but are usually _______
- Size & shape
- Symmetric
What is the only paranasal sinus not found in a cranial bone?
Maxillary sinuses
The maxillary sinus is divided into _______ sinuses by a _______
- 2 sinuses
- complete septum
Each sinus of the maxillary sinus is divided into ________ by a __________
- Subcompartments
- Partial Septum
The maxillary sinus is the ________ paranasal sinus
Largest
Which sinus is pyramid in shape?
Maxillary sinus
Which sinus has three thin walls?
Maxillary sinus
Which bone is the maxillary sinus not found in?
Cranial bone
Infections can start in the ______ and lead into the _______
- Teeth
- Maxillary sinus
How many elevations does the sinus floor have?
Several
The sinus floor has ______ corresponding to the _____ of the ____ and _____ upper molar teeth
- Several elevations
- Roots
- First
- Second
How do the maxillary sinuses drain?
Upwards
What does the maxillary sinus drain into?
Middle nasal meatus
What is the most common paranasal sinus to retain mucus and fluid?
Maxillary sinus
What does the maxillary sinus retain?
Mucus and fluid
Which sinus drains upward?
Maxillary sinus
What does the maxillary sinus show on x-rays?
Air-fluid level
What is the second largest sinus?
Frontal sinus
Where is the frontal sinus located?
Posterior to the glabella
Where does the frontal sinus drain?
Middle nasal meatus
What separates the frontal sinuses?
A septum
The frontal sinuses are generally ______ in males than females
Larger
Frontal sinuses are _________ in size
Rarely symmetric
Usually there are ______ or _____ frontal sinuses or sometimes _______
- 1
- 2
- None
The frontal sinuses are the _______ sinus
Second largest
Which sinus is located posterior to the glabella?
Frontal sinuses
Which sinus is rarely symmetric in size and shape?
Frontal sinuses
What sinus is seperated by a septum?
Frontal sinuses
Which sinus is generally larger in males than females?
Frontal sinuses
The ethmoid sinus is divided into ________
3 main groups
What groups is the ethmoid sinus divided into?
- Anterior
- Middle
- Posterior
Where are the ethmoid sinuses contained?
Within the lateral masses of the labyrinths of the ethmoid bone
How many ethmoid sinuses are there?
Number vary
Which sinus is divided into anterior, middle, and posterior?
Ethmoid sinus
Which sinus is contained within the lateral masses of the labyrinths of the ethmoid bone?
Ethmoid sinus
Which sinus varies in number?
Ethmoid sinus
Where does the posterior ethmoid sinuses drain?
Into the superior nasal meatus
How many posterior ethmoid sinuses are there?
Varies in number from 2-6
Where does the anterior and middle ethmoid sinuses drain?
Into the middle nasal meatus
How many anterior and middle ethmoid sinuses are there?
Each group varies in number from 2-8
Which sinus drains into the superior nasal meatus?
Posterior ethmoid sinuses
Which sinus varies in number from 2-6?
Posterior ethmoid sinus
Which ethmoid sinus drains into the middle nasal meatus?
Anterior and middle ethmoid sinus
Which sinus varies in number from 2-8?
Anterior and middle ethmoid sinus
Where does the sphenoid sinuses drain?
Sphenoethmoidal recess of the nasal cavity?
How many sphenoid sinuses are there?
Usually one or two
Do the sphenoid sinuses exceed more than 2?
No
The sphenoid sinuses ______ in size and shape, but are usually ______
- Vary
- Asymmetric
Where are the sphenoid sinuses located?
- In the body of the sphenoid bone directly below the sella turcica
- Lies between the dorsum sellas and the posterior ethmoid air cells
Which sinus drains into the sphenoethmoidal recess of the nasal cavity?
Sphenoid sinus
Which sinus usually has one or two, but never exceed two?
Sphenoid sinus
Which sinus varies in size and shape but is usually asymmetric?
Sphenoid sinus
Which sinus is located in the body of the sphenoid bone directly below the sella turcica and lies in between the dorsum sellas and the posterior ethmoid air cells?
Sphenoid sinus
How many passages does the osteomeatal complex have and what are they?
- 2
- Infundibulum
- Middle nasal meatus
What is sinusitis?
Infection of the sinuses due to obstruction of all or part of the osteomeatal complex
What is the osteomeatal complex composed of?
Drainage pathways between the frontal, maxillary, and ethmoid sinuses
What is the infection of the sinuses due to obstruction of all or part of the osteomeatal complex called?
Sinusitis
What is composed of drainage pathways between the frontal, maxillary, and ethmoid sinuses?
The osteomeatal complex
What is has two key passageways from the infundibulum and middle nasal meatus?
Osteomeatal complex
How many drainage pathways does the osteomeatal complex have and what are they?
- 3
- Frontal, maxillary, and ethmoid sinuses
What are orbits?
Cone-shaped, bony- walled cavities
What is the base of the orbit?
The rim of the orbit
What is the apex of the orbit?
Posterior portion which corresponds to the optic foramen
How many degrees do the orbits project from the OML?
30-degrees superiorly
How many degrees do the orbits project from the MSP?
37-degrees away from
What are the cone-shapes, bony-walled cavities called?
Orbits
What is the rim of the orbit called?
Base
What is the posterior portion which corresponds to the optic foramen called?
Apex
The orbits project 30-degrees superiorly from the ________
OML
The orbits project 37-degrees away from the _______
MSP
What does the posterior portion (apex) of the orbits correspond with?
Optic foramen
How many bones forms the orbits and what are they?
- 7
- Frontal
- Sphenoid
- Ethmoid
- Maxilla
- Zygoma
- Lacrimal
- Palatine
How many cranial bones forms the orbits? What are they?
- 3
- Frontal
- Sphenoid
- Ethmoid
How many facial bones forms the orbits? What are they?
- 4
- Maxilla
- Zygoma
- Lacrimal
- Palatine
What is the circumference of orbit?
The outer rim
What is the outer rim?
Circumference of orbit
What does the maxilla form of the orbit?
The floor
What does the zygoma form of the orbit?
The lateral walls
What does the frontal form of the orbit?
orbital plate of the frontal bone forms most of the roof of the orbit
What bone forms the floor of the orbits?
Maxilla
What bone forms the lateral walls of the orbits?
Zygoma
What bones contains an orbital plate that forms most of the roof of the orbit?
Frontal
How many holes/openings does each orbit contain? What are they?
- 3
- Optic foramen
- Superior orbital fissure
- Inferior orbital fissure
Each orbit contains ____ holes/openings in the _________
- 3
- Posterior portion
What is the optic foramen?
A small hole in the sphenoid bone
What is the optic foramen a passageway for?
Optic nerve (CN II)
What does the optic foramen correspond to?
Apex of the orbit
What is the superior orbital fissure?
Opening between the greater and lesser wing of the sphenoid bone
Where is the superior orbital fissure located?
Lateral to the optic foramen
What is the superior orbital fissure a passageway for?
4 cranial nerves (CN III-VI)
What is the small hole in the sphenoid bone called?
Optic foramen
What has a passageway for the optic nerve (CN II)?
Optic foramen
What correspond to the apex of the orbit?
Optic foramen
What is another name for optic nerve?
CN II
Whats another name for CN II?
Optic nerve
What is the opening between the greater and lesser wing of the sphenoid bone?
Superior orbital fissure
What is located lateral to the optic foramen?
Superior orbital fissure
What is a passageway for 4 cranial nerves (CN III-VI)?
Superior orbital fissure
Where is the inferior orbital fissure located?
Between the maxilla, zygomatic bone, and the greater wing of the sphenoid
What is the inferior orbital fissure a passageway for?
Maxillary branch of the trigeminal nerve (CN V)
What is a sphenoid strut?
Small root of bone separating the superior orbital fissure and the optic canal
What is located between the maxilla, zygomatic bine, and the greater wing of the sphenoid?
Inferior orbital fissure
What is a passageway for the maxillary branch of the trigeminal nerve (CN V)?
Inferior orbital fissure
Whats another name for trigeminal nerve?
CN V
Whats another name for CN V?
Trigeminal nerve
What is the small root of bone separating the superior orbital fissure and the optic canal?
Sphenoid strut
What is the most common fracture to the orbital floor?
Blowout fracture
What is a blowout fracture?
When orbit contents “blow out” into the floor of the orbit
What usually causes a blowout fracture?
Blunt force trauma
What kind if people do you usually see blow out fractures in?
Athletes such as boxers or baseball players
A blowout fracture is the _____ fracture to the orbital floor
Most common
What is the fracture called when orbit contents “blow out” into the floor of the orbit?
Blowout fracture
What orbital fracture is usually caused by blunt force trauma?
Blowout fracture
Which fracture is usually seen in athletes such as boxers or baseball players?
Blowout fractures
What is a tripod fracture?
A fracture that involves the zygomatic bone and its three connections: Frontal, maxilla, and temporal
A tripod fracture heals ______
Rapidly
What fracture involves the zygomatic bone and its three connections: Frontal, tempora, and maxilla?
Tripod fracture
Which orbital fracture heals rapidly
Tripod fracture
