Orbit And Osteology Flashcards
What are the seven bones that form the orbit?
Frontal, zygomatic, maxilla, palatine, lacrimal, ethmoid, sphenoid
These bones create the structure of the eye socket.
What are the components of the four orbital walls?
Medial wall, lateral wall, roof, inferior wall
Each wall has specific bones contributing to its structure.
What is the purpose of the paranasal sinuses?
- Decrease the weight of the head
- Increase vocal resonance
- Isolate sensitive structures from temperature fluctuations
- Humidification and warming of inhaled air
Paranasal sinuses surround the nasal cavity and extend it.
What are the anterior foramina of the orbit?
Supraorbital, infraorbital, zygomaticofacial, zygomaticotemporal
These foramina allow the passage of nerves and vessels.
What are the posterior foramina of the orbit?
Superior orbital fissure, inferior orbital fissure, optic canal
These foramina also contain important structures for eye function.
What structures pass through the superior orbital fissure?
- Lacrimal nerve
- Frontal nerve
- Superior ophthalmic vein
- Oculomotor nerve divisions
- Nasociliary nerve
- Abducens nerve
It lies between the greater and lesser wings of the sphenoid bone.
What is Tenon’s capsule?
A thin, collagenous membrane surrounding the globe, muscles, and optic nerve
It merges with the conjunctiva anteriorly.
Fill in the blank: The orbit is surrounded by the paranasal sinuses, with thin bony separations. Orbital blow out fractures commonly allow herniation of the orbital contents into the _____ and/or _____ sinuses.
[maxillary] and [ethmoid]
This highlights the risk of infection spread from sinuses to the orbit.
What are the clinical signs of an inferior blow out fracture?
- Diplopia
- Enophthalmos
- Reduced sensation over the ipsilateral cheek
These symptoms arise due to the fracture affecting the orbital structures.
True or False: The orbit is a single cavity that protects the eye.
False
The orbit consists of two separate bony cavities.
What are the functions of the paranasal sinuses?
- Decrease the weight of the head
- Increase vocal resonance
- Isolate sensitive structures from temperature fluctuations
- Humidification and warming of inhaled air
These functions are essential for respiratory health and comfort.
What is the significance of the optic canal?
It contains the optic nerve and ophthalmic artery
This canal is crucial for vision as it transmits important structures to the eye.
What are the symptoms of orbital cellulitis?
- Proptosis
- Eye movement restrictions
- Double vision
- Optic nerve dysfunction
These symptoms indicate an infection that can affect the orbit.
How many paranasal sinuses are there?
Four
The sinuses are named after the facial bones they are associated with.
What is the anatomical location of the superior orbital fissure?
Between the greater and lesser wings of the sphenoid bone
This fissure is a key passage for several cranial nerves and vessels.
Fill in the blank: The periorbita is the periosteum of the internal orbit, which is loosely attached to the four _______ walls.
[bony]
The periorbita helps protect the contents of the orbit.
What can be a result of trauma to the orbit?
Fractures and herniation of orbital contents
This can lead to complications such as orbital cellulitis or vision impairment.
What is the content of the inferior orbital fissure?
- Zygomatic nerve
- Infraorbital nerve
- Inferior ophthalmic vein
- Branches of the pterygopalatine ganglion
These structures are crucial for the functioning of the face and eye.
