physiology of taste and smell Flashcards
where does the tongue develop embryology
develops in the back of the neck in occipital somites
mesoderm = muscle
ectoderm = surface, branchial arch
what develops from the first brachial arch
tuberculum midline and lateral lingual swellings
from the mucosal surface of the anterior 2/3 of the tongue
trigeminal nerve (CN V) for touch and pain; facial nerve (CN VII) for taste
what develops from the third brachial arch
cupula (hypobranchial eminence)
forms the posterior 1/3 of the tongue (pharyngeal tongue)
glossopharyngeal nerve (CN IX)
what develops from the mesoderm in the upper neck (occipital somites)
intrinsic and extrinsic muscles
hypoglossal nerve (CN XII)
what are the extrinsic muscle of the tongue
genioglossus, hyoglossus and styloglossus
- with palatoglossus, moves tongue back forwards up and down
what are the intrinsic muscles of the tongue
vertical, horizontal and longitudinal
what are the 5 primary taste
sour
salty
sweet
bitter
savoury/ umami
what chemicals create sour
acid, H+
what chemicals create salty
Na+
what chemicals create sweet
glucose
what chemicals create bitter
coffee, beer, quinine, blue cheese, olives
what chemicals create savoury/ umami
glutamate
what is the purpose of bitter taste
bitterness is the most sensitive and has a protective function
- protects against poison ingestion
- children will not eat bitter things, but you can train yourself to like them
what innervates the anterior 2/3 of the tongue
lingual nerve (trigeminal, CN V)
chorda tympani (facial, CN VII)
what innervates the posterior 1/3 of the tongue
glossopharyngeal (CN IX)
