Paranasal Sinuses and Guttural Pouches

Question 1

define sinus anatomically

Answer 1

a cavity within a bone or a tissue

Question 2

define paranasal sinuses

Answer 2

air-filled extensions of the nasal cavity that invade some of the facial bones

Question 3

list the paransal sinuses present in the canine, equine, and bovine

Answer 3

canine: frontal sinuses are the only true paransal sinuses in canines; located within frontal bone (have a maxillary recess that is a depression, not a sinus)

equine:
1. maxillary: largest, has two compartments
-RMS: rostral maxillary sinus
-CMS: caudal maxillary sinus
2. frontal sinus
3. sphenopalatine sinus
4ish. conchofrontal: frontal + dorsal conchal

bovine: have numerous septa that form a labyrinth of interconnected spaces
1. maxillary sinus (not divided by a septa in bovine; drains into middle nasal meatus); have a delicate, thin-walled extension called the lacrimal bulla
2. palatine sinus: communicates with maxillary sinus (drains into middle nasal meatus)
3. rostral frontal sinus: drains into ethmoidal meatus; forms a conchofrontal sinus with dorsal conchal sinus
4. caudal frontal sinus: largest, caudal to orbits, has 3 diverticula, drains into ethmoidal meatus (DOES NOT COMMUNICATE with rostral frontal)

Question 4

distinguish between nasal cavities and paranasal sinuses in all 3 species

Answer 4

look at pictures?

Question 5

distinguish between nasal conchae and conchal sinuses in all 3 species

Answer 5

conchal sinuses are air-filled spaces within a concha/turbinate; canines and felines DO NOT have conchal sinuses!!

horse and cow:
dorsal conchal sinus within dorsal concha, middle conchal sinus within middle concha, ventral conchal sinus within ventral concha

Question 6

describe the communication pathways between the conchal sinuses and the paranasal sinuses, and between all the sinuses and the nasal cavities

Answer 6

equine:
1. maxillary sinuses: each side has 2 non-communicating compartments divided by a bony septum, creating RMS and CMS
2. ventral conchal sinus: communicates with the rostral maxillary sinus
3. conchofrontal, middle conchal, and sphenopalatine sinuses all communicate within the caudal maxillary sinus
4. all sinuses communicate either directly or indirectly with the middle nasal meatus via the nasomaxillary opening/aperture

bovine:
1. palatine and maxillary sinuses communicate with each other and with the middle nasal meatus through the nasomaxillary opening/aperture
2. rostral frontal sinus forms conchofrontal sinus with dorsal conchal sinus
3. rostral and caudal frontal sinuses do NOT communicate
4. cornual diverticulum, if patent, communicates with the caudal frontal sinus

Question 7

define what guttural pouches are and how to access them

Answer 7

1. dilations of the internal auditory tubes
2. two pouches, bilaterally positioned, separated by a thin septum and do not normally communicate
3. normally air filled
4. each pouch subdivided into medial and lateral compartments by the stylohyoid bone; medial pouch usually largest
5. accessed via pharyngeal opening of the auditory tube, in the nasopharynx
6. susceptible to bacterial and mycotic infection

Question 8

list the species that have guttural pouches

Answer 8

equine only