L4 : tongue Flashcards
where does the tongue originate from ?
from the muscles of occipital metopes
when does formation of the tongue begin ?
at about 4 weeks
what pharyngeal arch is the tongue derived from (anterior 2/3rds)?
first pharyngeal arch
what are the 3 swellings that give rise to the mucous membrane of the anterior 2/3rds of the tongue ?
tubercular impair and 2 lingual swellings
what pharyngeal arch is the tongue derived from ?(posterior 1/3rds)
the 3rd arch
what swelling gives rise to the posterior 1/3rds of the tongue ?
hypo brachial eminence
where do the muscles of the tongue originate form ?
occipital somites
what nerves supply the sensory and taste sensations of the tongue ?
sensory (anterior 2/3rds):lingual branch of trigeminal (5th granola nerve )
taste : chordates tympani branch of facial nerve
posterior 1/3rd: glosso pharyngeal (ix cranial nerve )
what nerve is responsible for motor function of tongue ?
all muscles are supplied by hypoglossal nerve except palatglosal which is supplied by vagus nerve
describe the epithelium of the tongue .
keratinized stratified squamous epithelium covered with papillae
what are the characteristics of filiform papillae ?
- most numerous papillae
- cone shaped , each with a core of connective tissue covered by thick keratinized epithelium
- not associated with taste buds
what are the characteristics of fungiform papillae ?
scattered over the dorsal surface of tongue in-between filiform papillae
elevated smooth rounded structures
highly vascularized connectible tissue core .
covered by thin nonkeratinized covering epithelium
what are the characteristics of circumvallate papillae ?
located at junction of anterior. 2/3rd and post.1/3rd .
8-12 in number
lined with taste buds and openings to serous glands
where are taste buds found ?
oral cavity ( fungiform , foliate , and circumvallate papillae ) and pharynx
