UNIT 5: Tongue + Hypoglossal Nerve Flashcards
what is considered a muscular hydrostat
tongue
what is a muscular hydrostat
a fluid filled incompressible epithelial bag - the muscles serve as the fluid
a constant volume sys
any reduction in volume in one part is associated w an equivalent inc in another part
what are the two anatomical divisions of the tongue
oral tongue
pharyngeal tongue
oral tongue includes
anterior 2/3 w/i oral cavity (tongue dorsum aka superior surface)
tip, blade, front, back
pharyngeal tongue includes
posterior 1/3 aka tongue base
w/i oropharynx
what are the general features of the anterior 2/3 of the tongue? midline depression?
thick rough, epithelial covering
midline depression = longitudinal sulcus
4 types of papillae on ant 2/3 of tongue
fungiform
filiform
folliate (simple)
vallate
papillae
microscopic projections
fungiform papillae are …. and contain …
mushroom shaped paillae
contain taste buds
where do you find fungiform papillae
scattered over tongue dorsum and sides
predominant on tip of tongue
fungiform papillae are innervated by
chorda tympani of CN VII
which type of papillae is most numerous
filiform papillae
describe filiform papillae, do they have taste buds? purpose?
very small, sharp pointed projections on tongue dorsum
no taste buds, used to grip food
what type of paillae is highly dev in cats?
filiform
which papillae accounts for the rough texture of the tongue dorsum?
filiform
how are filiform papillae arranged?
in parallel rows
describe foliate papillae
variable in humans
mucosal folds present on the lateral aspects of the tongue, anterior to the palatoglossal arch
aka simple papillae
what are foliate papillae covered by
epithelium containing taste receptors
which are the largest papillae
vallate
how are vallate paillae arranged? what shape are they?
7-12 arranged in posteriorly pointing arrowhead
cylinder-shape surrounded by a moat w taste buds on the cylinder and in the wall of the moat
what division do the vallate papillae form?
division bw anterior 2/3 and posterior 1/3 of tongue
vallate papillae are innervated by
CN XI (glosso)
describe the surface of the pharyngeal tongue (post 1/3)
smooth, thin, nodular covering due to presence of lingual tonsils in underlying submucosa
terminal sulcus is
a groove on the pharyngeal tongue that is just posterior to circumvallate papillae
foramen cecum is a
small pit w/i the terminal sulcus on the pharyngeal tongue - marks the embryological origin of the thyroid gland
median and lateral glossoepiglottic folds on the pharyngeal tongue form the
valleculae at junction w epi
describe the ventral and inferolateral tongue
thin, smooth mucous membrane
lingual frenulum is
a fold of mucosa that attaches underside of tongue to floor of mouth
on either side of the lingual frenulum you will see
lingual veins seen thru thin mucosa
sublingual papilla is
opening of duct of submandibular salivary gland (L and R on either side of mouth)
sublingual folds of mucosa overlie the ______, with openings along the
sublingual salivary glands, w openings along the sublingual fold