Sinuses and nasal cavity 2

Question 1

What three components make up the sinuses?

Answer 1

• external nose
• nasal cavities
• paranasal sinuses

Question 2

What is the external nose or nares?

Answer 2

• fixed bony case and cartilaginous framework - alar cartilage
• paired nasal cavities separated by nasal septum

Question 3

Describe the external nose of the dog?

Answer 3

• apical portion = nasal plane/plate, philtrum in centre

Question 4

What is the nostril called (equine)

Answer 4

• flare

Question 5

what is the nasal diverticulum or alar fold in a horse?

Answer 5

• false nostril
• small pocket
• filters air

Question 6

What makes up the caudal boundary of the nasal cavity?

Answer 6

• cribiform plate of the ethmoid bone

Question 7

What makes up the ventral boundary of the nasal cavity?

Answer 7

• continuous with the nasopharynx

Question 8

What makes up the dorsal boundary of the nasal cavity?

Answer 8

• maxilla and the palatine processes of the incisive bone

Question 9

What is the median septum? (nasal cavity)

Answer 9

• rostral continuation of the ethmoid bone
• made up if hyaline cartilage
• divides the nasal cavity into left and right halves

Question 10

What is the nasal cavity?

Answer 10

• twinned pair of cavities, separated by septum

Question 11

The nasal cavity contains what bones?

Answer 11

• turbinate bones covered by mucosa (conchae)

Question 12

Certain bones bordering the nasal cavity are thickened by air spaces – they are not part of the nasal cavity but communicate with it - what are these spaces?

Answer 12

• paranasal sinuses

Question 13

What is a vestibule?

Answer 13

• most rostral part of the nasal cavity
• not empty it contains alar folds

Question 14

What is the size of the nasal cavity reduced by?

Answer 14

• paranasal sinuses in neighbouring bones
• embedded portion of upper cheek teeth (especially in horse)
• turbinate bones
• mucosal covering of the turbinate bones

Question 15

What are turbinate bones?

Answer 15

• thin bony plates that project into the nasal cavity

Question 16

What is conchae?

Answer 16

• cartilage or ossified scrolls
• arose from the ethmoid bone
• increase respiratory area create turbulence (filter, warms, cools incoming air)

Question 17

What do the dorsal and ventral conchae do?

Answer 17

• divide nasal cavity into nasal ducts (meatuses)
• branch from common meatus near septum

Question 18

What are the 3 nasal meatuses?

Answer 18

• dorsal nasal meatus
• middle nasal meatus
• ventral nasal meatus

Question 19

There are also 2 concha in the nasal cavity What are they?

Answer 19

• dorsal nasal concha
• ventral nasal concha

Question 20

What are paranasal sinuses?

Answer 20

• ventilated spaces connected to the nasal cavity

Question 21

How do paranasal sinuses develop?

Answer 21

• develop as blind ending pouched between lamina of the bones of the skull

Question 22

What is the frontal paranasal sinus?

Answer 22

• consists of space within the bones between the cranial cavity and the nasal cavity

Question 23

What is the maxillary paranasal sinus?

Answer 23

• space within caudolateral part of the upper jaw, above the caudal cheek teeth

Question 24

The purpose of paranasal sinuses is not clear however, what are the possible purposes?

Answer 24

• reduce bone thus weight of skull
• insulation/cooling of the brain
• increase insertion space for teeth

Question 25

Describe the dogs paranasal sinuses

Answer 25

- poorly developed - frontal - 3 chambers (rostral, lateral and medial compartments) - drain separately into nasal cavity - maxillary - communicates with nasal cavity - known as the maxillary recess

Question 26

Describe the equine paranasal sinuses

Answer 26

- frontal sinuses - closest to surfaces of forehead - maxillary sinuses - largest - divided by septum into rostral and caudal - house the roots of the molars - sphenopalatine and ethmoidal sinuses

Question 27

Describe the paranasal sinuses in cattle

Answer 27

- not fully developed until 7 yrs old - frontal sinus - palatomaxillary sinus - lacrimal sinus - sphenoidal sinuses - within conchae - conchal sinuses