Dorsum of the tongue. Oral Part exhibit lingual papillae of the 4 types. Oral Part of Tongue divided into Left & right halves by shallow median groove

Transcription

1 Histology of TONGUE

2 Figure 22.13

3 Dorsum of the tongue Oral Part of Tongue divided into Left & right halves by shallow median groove Oral Part exhibit lingual papillae of the 4 types a. filiform papillae, b. fungiform papillae, c. vallate papillae & d. foliate papillae Pharyngeal Part of Tongue devoid of papillae, contains lymphatic nodules - lingual tonsils

4 Most numerous is the filiform papillae it appears short and bristles macroscopically. Fungiform papillae are small red globular. Circumvallate papillae are arranged in rows in front of sulcus terminalis.

5 Tongue

6 Filliform Fungiform Circumvallate

7 Tongue

8 FILIFORM PAPILLAE Most numerous type. Entire dorsal surface of tongue. Lined stratified squamous keratinized epithelium No taste buds Increase the friction between tongue & food

9 Clinical correlation Hairy papillae Filiform papillae are hypertrophied and elongated. These hair (papillae) are stained black, brown, yellowish white by food or oral flora

10 FUNGIFORM PAPILLAE Rounded reddish elevations high vascular connective tissue core Looks like fungi narrow base & broad top Scattered all over anterior 2/3 rd of tongue most numerous in the tip of tongue Contains taste buds on surface.

11 Tongue

12 CIRCUMVALLET PAPILLAE Circumvallate papillae are the largest and least common type 8 to 12 in number. Arranged in a single row infront & parallel to sulcus terminalis Each papillae is surrounded by a circular sulcus/ groove (trench) called vellum which separates rest of the part

13 CIRCUMVALLET PAPILLAE These papillae has broad circular top and narrow base. Lined by stratified squamous non-keratinized epithelium Base of each papillae contains circular and longitudinal muscle fibers

14 CIRCUMVALLET PAPILLAE It also presents numerous of serous glands seen near the base and groove of papillae called serous glands of von ebner Serous secretions helps in appreciating taste of food by dissolving food particles in it Epithelium lining the walls of the sulcus shows numerous of taste buds

15 Foliate papillae Shape leaf like Rudimentary in humans It is functional in lower animals such has cows and buffaloes.

16 Taste bud

17 Taste bud It is a center for appreciation of taste Located in papillae of tongue In circumvallate it is located in groove In fungiform on surface or on its lateral part Filiform taste buds are absent Shape of taste bud is barrel.

18 Taste bud Made up modified epithelial cells Each bud has cavity which opens on the surface through gustatory pore. There are 5 types of cells

19 Taste bud There are 5 types of cells Type I Supportive cells Long elongated epithelial cells Darkly stained Upper pole bears fine microvilli Lower pole is close to basal cells

20 Taste bud Type II & III Gustatory cells or receptor cells It is the bipolar neuroepithelial cells Lightly stained Upper pole bears microvilli Lower pole is associated to sensory nerve fibers

21 Taste bud Type IV Basal cells or stem cells These pyramidal cells It is present close to the basement membrane of the epithelium Type V These cells forms the sheath or boundary

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23 General plan of GIT Lamina propria Serosa/ Adventitia

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25 Mucosa - Stratified squamous nonkeratinized epithelium Papillae of lamina propria Muscularis mucosa longitudinal muscle bundles, mainly Submucosa :- Oesophageal glands tubulo - alveolar mucus acini in Muscularis externa: Upper one-third striated muscle Lower one-third smooth muscle Middle one-third striated & smooth muscle Adventitia/ Serosa

26 MUCOSA SUBMUCOSA Stratified squamous nonkeratinized epithelium Lamina propria Oesophageal glands Muscularis mucosa MUSCULARIS EXTERNA Inner circular layer Outer longitudinal layer SEROSA Connective tissue

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29 Clinical anatomy: Oesophagitis : reflux of gastric contents causes heart burn Oesophageal varices: anastomosis dilate in lower end of oesophagus causes vomitting of blood