Tongue Flashcards
What kind of tissue covers the tongue?
mucosa
The tongue is divided into two region. What are the two regions and what defines the division?
the tongue is divided into the body (anterior 2/3) and the base (posterior 1/3). The two regions are separate by the terminal sulcus
What is the terminal sulcus of the tongue?
it is a V-shaped line dividing the body and base of the tongue. It is the result of the two regions of the tongue having 2 different developmental origins that fuse.
What is the shallow depression at the midline of the terminal sulcus called and what is its developmental origin?
it is called the foramen cecum and it is the origin of the thyroid gland primordium
What is the depression in the midline of the body (anterior 2/3) of the tongue called?
dorsal median sulcus
Where are lingual papillae located on the tongue?
anterior 2/3 of the dorsum of the tongue
The most numerous type of lingual papillae that are pointed apically?
filiform papillae
The rounded, mushroom-like lingual papillae?
fungiform papillae
The large lingual papillae that are distributed in a V-shaped pattern just anterior to the terminal sulcus?
circumvallate papillae
How many circumvallate papillae are there usually?
8-12
Which lingual papillae have mucosal glands called Von Ebner’s glands associated with them?
circumvallate papillae
The ridge like lingual papillae located on the posterolateral surfaces of the tongue?
foliate papillae
Which of the 4 lingual papillae contain taste buds?
all but the filiform, so circumvallate, fungiform and foliate
Where other than the lingual papillae are taste buds found?
palate and epiglottis
Are the number of taste buds constant throughout life?
no, they diminish with age
The posterior 1/3 of the tongue is also called……
the pharyngeal tongue because it faces posteriorly towards the pharynx
What covers the surface of the posterior 1/3 of the tongue?
lingual tonsils
What are lingual tonsils?
aggregates of lymphoid tissue in the mucosa of the posterior 1/3 of the tongue
What borders the pharyngeal tongue at the base?
the epiglottis
The depressions located between the posterior base of the tongue and the root of the epiglottis?
epiglottic valleculae (vallecula = valley in Latin)
What nerve provides general sensory innervation to the anterior 2/3 of the tongue and what is it a branch of?
lingual nerve, a branch of mandibular nerve (V3)
What nerve provides taste innervation to the anterior 2/3 of the tongue?
facial nerve (CN VII) via the corda tympani
What nerve provides general sensory innervation to the posterior 1/3 of the tongue?
glossopharyngeal nerve (CN IX)
What nerve provides taste innervation to the posterior 1/3 of the tongue?
glossopharyngeal nerve (CN IX)
All but one of the extrinsic muscles of the tongue are innervated by what nerve? Which muscle is the exception and what is it innervated by?
all are innervated by hypoglossal nerve (CNXII) except palatoglossus muscle which is innervated by the same nerve that innervates most of the muscle of the pharynx, vagus nerve (CNX)
The fan shaped extrinsic tongue muscle that protracts the tongue?
genioglossus muscle
What is the origin and insertion of the genioglossus muscle?
O: inner surface of mentum of mandible
I: body of tongue and body of hyoid bone
What is the origin of styloglossus?
styloid process of the temporal bone
What is the origin of hyoglossus?
greater Cornu of the hyoid bone
What ist he origin of palatoglossus?
lateral portion of the palate
What is the action of genioglossus?
bilateral contraction: protraction and depression of the tongue
unilateral contraction: protraction and contralateral deviation
What is the action of styloglossus?
elevate and retract the tongue
What is the action of hyoglossus?
depress and protract the tongue
What is the action of palatoglossus?
fauces sphincter and elevate tongue
