TONGUE.pdf

tongue

1. TONGUE

3. STRUCTURE
OF
TONGUE

20. TASTE BUD

27. TASTE PATHWAY
•Tasteimpulsesfromtheanterior2/3rdofthe
tonguepassfirstintothelingualnerve
(Trigeminalnerve)-chordatympani(facial
nerve)-tractussolitariusinthebrainstem.
•Posterior1/3rdofthetongue–
glossopharyngealnerve-tractussolitarius
•Posteriormost,pharynx–vagusnerve-
tractussolitarius

29. Cont..
•Nucleusofthetractussolitarius(2ndorder
neurons)(Medullaoblongata)-thenucleusof
thethalamus(3rdorderneurons)-lowertip
ofthepostcentralgyrusintheparietal
cerebralcortex(Gustatorycortex)

30. Cont..
•Theseareastransmitsignalstothe
submandibular,sublingual,andparotid
glandstohelpcontrolthesecretionofsaliva
duringtheingestionanddigestionoffood.

31. Factors Influencing Taste Sensation
1.Temperatureofsubstance-maximum
sensitivitytotasteisobtainedat30-40
degreeC
2.Olfaction–asitaffectsflavor
3.Individualvariation-decreaseintaste
sensitivityinolderpeopleduetoatrophyof
tastebuds
4.Sex-womenaremoresensitivetosweetand
saltandlesssensitivetosourthanmen.
5.Adaptation-tastebudsadaptquicklytoa
particulartaste

32. Taste Sensation Abnormalities
1.Ageusia-absenceoftastesensation-
congenitalorduetolesionoffacialor
glossopharyngealnerve.
2.Hypogeusia-diminishedtastesensationdue
tosomediseases.
3.Dysgeusia-alteredtastesensation.

33. PATHOLOGICAL TERMS
1.Tongue-tie-Itisalsoknownasankyloglossia,
whichisaconditioninwhichaperson's
tongueremainsattachedtotheflooroftheir
mouth.

34. Cont..
2.Glossitisreferstoinflammationofthe
tongue.Theconditioncausesthetongueto
swellandchangecolorandtexture.

35. Cont..
3.Macroglossia-Itisanabnormalenlargement
ofthetongue.
4.Atrophicglossitis-Itisaconditioninwhich
thetongueismissingsomeorallofits
papillae,makingitsusuallyroughsurface
smooth.

36. Changes In Color Of Tongue
1.Abrightpinkcoloronthetongueismost
oftenduetoadeficiencyiniron,folicacid,
orvitaminB-12.
2.Awhitetongueisusuallyaresultofsmoking,
drinkingalcohol,poororalhygiene,or
candidainfection.

37. Cont..
3.Leukoplakiaanderythroplakiacancause
whiteorredpatchesonthetonguethatcan
beprecursorstocancer.