4. Oral cavity- tongue Flashcards
What is the oral cavity ?
Space enclosed by the lips and cheeks, filled with the tongue
where is the oral cavity proper?
between teeth, space between lower and upper dental arcades
what is the oral vestibule
the space between the teeth and cheeks
what muscle are cheeks mainly formed of?
buccinator muscle
what do lips bind?
oral tissue
how are lips innervated?
innervated by sensory fibres: 3 branches of the trigeminal nerve
what minor gland is present in the lips?
labial gland
What epithelium lines the lips?
stratified squamous epithelium
where is the soft palate found?
The dorsal part of the oral cavity: caudal aspect
What does the soft palate do?
closes the nasal passage during swallowing
where is the hard palate found?
The dorsal part of the oral cavity: rostral aspect
what bones make up the hard palate?
- palatine
- pre maxilla
-part of maxilla
what makes the hard palate protected?
highly keratinised
what is found on the hard palate that aids in sense of smell and taste?
incisive pappilae
what is the vomeronasal organ responsible for?
semiochemical signal detection (pheromones)
where is the vomeronasal organ found?
Close to the vomer, incisive papillae open into the incisive duct that links the mouth with the nasal cavity
Where is the tongue located?
Ventral aspect of the oral cavity, attached to the hyoid bone and mandible hence mobile
what epithelium covers the tongue?
stratified squamous epithelium
What has the surface of the tongue got a large number of?
projections called papillae and taste buds
what are marginal papillae only present in?
new-born dogs
What Is the Lyssa of the tongue?
Central midline of the tongue consisting of a cord of skeletal muscle and adipose tissue and surrounded by dense connective tissue
What is the function of the Lyssa
creates scoop to aid drinking
what did the Lyssa create in dogs?
median sulcus
what is the torus lingua? which species is it found in?
swelling across the tongue which pushes food against the hard palate: Cattle, goats, alpaca
What is the frenulum?
body of the tongue is attached to the floor of the oral cavity by the frenulum
what is adjacent, and on each side of the frenulum?
sublingual fold
what are the 2 divisions of muscles in the tongue?
intrinsic and extrinsic
Intrinsic muscles of the tongue?
muscle fibres orientated in 3 directions- longitudinal, transverse and vertical. Forms the tongue proper (curl, groove, bend)
what are the 3 extrinsic muscles of the tongue running lateral to medial?
stylo-glossus
hyo-glossus
genio-glossus
describe the stylo-glossus muscle of the tongue and its function.
long, thin muscle- retracts and elevates the tongue
describe the hyo-glossus muscle of the tongue and its function.
wide and flat muscle- retracts and depresses the tongue
describe the genio-glossus muscle of the tongue and its function.
fan-shaped muscle- caudal fibres protrude and rostral ones retracts the apex
describe the genio-glossus muscle of the tongue and its function.
fan-shaped muscle- caudal fibres protrude and rostral ones retracts the apex
what are the 2 divisions of lingual papillae?
- mechanical
- gustatory
what are the 4 mechanical lingual papillae?
- filiform
- conical
- marginal
- lenticular
Structure and function of filiform papillae?
hair-like structures on the dorsal surface: grips food e.g cats lapping up milk and eating
structure and function of conical papillae?
larger, covers torus lingua. Not found in horses. Provide traction for movement of food
Function of marginal papillae
newborn carnivores and piglets, aid in suckling
lenticular papillae structure and which species is it found in?
hard and horny due to heavy keratinisation in ox
What are the 3 gustatory lingual papillae?
- Fungiform
- Vallate
- Foliate
Where are fungiform papillae found and what shape do they have?
among filiform, found on dorsal rostral surface of the tongue, mushroom-shaped
where are vallate found on the tongue and what is there structure?
between the body and root of the tongue, large circular projections surrounded by a deep groove
Where is foliate papillae found on the tongue and in what species
edges of the tongue, found in horses and pigs, rarely cattle
motor innervation of the tongue
hypoglossal nerve (CN XII)
motor innervation of the tongue
hypoglossal nerve (CN XII)
what does damage to the hypoglossal nerve result in?
paralysis of the tongue
rostral 2/3 of tongue innervation
sensation = lingual nerve branch of trigeminal nerve ( CN V)
taste = facial nerve (CN VII)
