1. THE ANATOMY OF THE TOUNGE
THE STRUCTURE
The tongue is a pinkish, pear shaped structure in the oral cavity.
It’s divided into the following parts:
1.Apex – the anterior end part which rests behind the incisors, also known as the tip of
the tongue.
2. Body – it is the most part of the tongue
3. Root – it is the end part of the tongue which is mostly difficult to hold.
- It measures 1/3 of the posterior part of the tongue, which rests on the floor of the
mouth.
4. curved dorsum – it is the postero-superior surface of the tongue in the oral cavity and
partly in the oropharynx.
5. Sulcus terminalis – part of the tongue which divides the dorsum of the tongue up into
oral and pharyngeal cavities.
6. Inferior surface – rests on the floor of the mouth and can only be seen when the
tongue is raised
- The mucosa on the inferior surface forms the mucosal fold called
frenulum, which extends to the gingiva of the mandible.
2. - Opposite to frenulum lies the deep lingual vein shrimming through
the mucosa.
- The fringed fimriated fold, usually lies lateral to the???????
- The narrow longitudinal l fold called sublingual fold is contained in
the oral cavity by the mucosa
- The presence of the papillae makes the mucous membrane on the
anterior part to be often rough.
- Vallate papillae form a v-row on the anterior of the sulcus terminalis.
- The vallate papillae are surrounded by deep trenches which are studded
with the taste buds and the ducts of the serous glands of the tongue.
-It opens into :> foliate papillae which is a small lateral fold of the lingual
mucosa.
>filiform papillae which is scaly, long, sensitive and numerous pinkish grey conical
projections, arranged in rows parallel to the sulcus terminalis, except at the apex,
arranged in a transverse way.
> Fungal papillae which is a mushroom shaped pink spots scattered on the filliform
papillae, but more numerous at the apex and at the lateral margins of the tongue.
Muscles of the tongue
The muscles of the tongue are in two forms, i.e. extrinsic and intrinsic.
3. Extrinsic muscles
1. Genioglossus – a paired muscle which arises from the mental spine of the
above geniohyiod.
- depresses the tongue
- It draws the tongue forward towards the floor of the mouth.
- Also helps the tongue to stick out
- move the tongue forward
2. Hyoglossus – arises from the greater horn of the hyoid bone
- depresses the tongue
- situated lateral to the genioglossus
- move the tongue backward and forward
3. Styloglossus – arises from the styloid process
- elevates the tongue
- retracts the tongue
- Also helps the tongue to rise up to the wall.
4. Palatoglossus – helps the tongue to rise up to the wall.
Intrinsic muscles – the muscles which are located inside the tongue, not
attached to bones.
4. 1. Superior and inferior longitudinal muscles – passes near the dorsum of the
tongue and the inferior surface of the tongue, from its tip to its base.
- They shorten and thicken the tongue.
- Retracts the tongue.
2. Transverse muscles – the most powerful muscles, consisting of transverse
fibers, some of which radiate into the lingual septum, lingual aponeorosis,
and lateral margins of the tongue.
- Protrudes the tongue
- Also lengthens and narrows the tongue.
3. Vertical muscles – composed of fiber bundles that pass from the dorsum of
the tongue to its inferior surface.
- It also protrude the tongue
- Lengthens and narrows the tongue
4. Verticalis – contains fibers bundles and runs in the free part of the tongue
from the upper to the lower surface.