Developed by: Sorcha McCaughley & Mark Brims
Approved by: Gawain Hammond & Maureen Bain
Supported by: The Chancellor’s Fund

START!
Developed by: Sorcha McCaughley & Mark Brims
Supported by: The Chancellor’s Fund

• The Eye Q1
• The Ear Q2

Canine
A
Canine – Contrast showing duct in (ii).
• (i) A makes up part of the
Orbit. What is it?
– Zygomatic Arch
– Zygomatic Process
• (ii) Which of the fossae, foraminae and fissures in the Orbit is connected, via a duct, to the nasal cavity?
– Ethmoidal Foraminae
– Lacrimal Sac Fossa
– Orbital Fissure

 Correct 
Canine
• Yes! A is the Zygomatic
Arch !
• The Zygomatic Process is the incomplete
Zygomatic Arch in horses and ruminants.
• Try (ii)!
• Choose a new question.
Bovine
Zygomatic
Arch
Zygomatic
Process

 Incorrect 
• No, A is not the Zygomatic
Process!
Canine
• Remember: the
Zygomatic Process is the incomplete Zygomatic
Arch found in horses and ruminants.
• Try again!
• Choose a new question.
Bovine
Zygomatic
Arch
Zygomatic
Process

 Correct 
• Yes! The Lacrimal Sac
Fossa connects with the
Nasolacrimal Duct!
• Try The Ear Q2!
• Choose a new question.
Nasolacrimal
Duct

 Incorrect 
• No, the Ethmoidal Foraminae do not connect with the nasal cavity.
• Blood vessels and branches of the Ophthalmic nerve are found in the Ethmoidal Foraminae.
• Try again!
• Choose a new question.

 Incorrect 
• No, the Orbital Fissure does not connect with the nasal cavity.
• The Orbital Fissure carries nerves and the ophthalmic vein.
• Try again!
• Choose a new question.

B
A
• In this x-ray you can see the outline of the ear.
• (i) Why is it not as white as the bones of the skull?
– Answer.
• (ii) What is A?
– Tympanic Bulla
– External Ear Cartilages
– External Acoustic
Meatus
• (iii) What is B?
– Tympanic Bulla
– External Ear Cartilages
– External Acoustic
Meatus

• Normally, cartilage cannot be seen on an x-ray as it is softer and less dense than bone.
• This x-ray would be described as ‘underexposed’. This means that the soft tissue structures are more visible.
• Try (ii)!
• Choose a new question.

 Correct 
• Yes! A is the External Ear Cartilage !
• It is not usually visible on x-rays as it is cartilage, not bone.
• Try (iii)!
• Choose a new question.

 Incorrect 
• No, A is not the
Tympanic Bulla.
• The Tympanic Bullae are shown in this x-ray.
Tympanic
Bulla
• Try again!
• Choose a new question.
Tympanic Bullae

 Incorrect 
• No, A is not the External Acoustic Meatus.
• The External Acoustic Meatus connects the
External Ear to the Tympanic Bullae.
• Try again!
• Choose a new question.

 Correct 
• Yes! B is the External
Acoustic Meatus!
• The outer part, nearest the external ear, is cartilagenous; it is rarely visible on x-rays.
• The inner part, as it approaches the Tympanic
Bulla, is osseus; it can sometimes be seen in xrays.
• Choose a new question.
External Acoustic
Meatus

 Incorrect 
• No, B is not the External
Ear Cartilage.
• The External Ear
Cartilages support the pinna of the Ear.
• Try again!
• Choose a new question.
External Ear
Cartilage

 Incorrect 
• No, B is not the
Tympanic Bulla.
• The Tympanic Bulla is found at the end of the
External Acoustic
Meatus.
• Try again!
• Choose a new question.
Tympanic
Bulla
Tympanic Bullae