Tongue – Parts, Muscles, Nerve Supply, Blood Supply, Lymphatic Drainage

Review of: Tongue
Anatomy Note:
K Vishnu Nambiar
Version:
1.0.4

Reviewed by:
Rating:
5
On August 18, 2016
Last modified:June 1, 2018

Summary:

This is an article completely about the anatomy of the tongue. I had tried my best to include everything in this chapter. If you have anything else to know please comment it below.

Contents:
1. What is tongue?
2. Development.
3. Functions.
4. Parts.
5. Mucous Folds.
6. Nerve Supply.
7. Blood Supply.
8. Lymphatic Drainage.
9. Muscles of Tongue.
9.1. Extrinsic Muscles
9.2. Intrinsic Muscles.
9.3. Nerve Supply of Muscles.
9.4. Blood Supply of Muscles.

1. What is tongue?

The tongue is a highly sensitive muscular organ which lies in the oral cavity and is concerned with mastication, deglutition or swallowing, speech, and taste.


2.Development:

The tongue is developed in the endodermal floor of pharynx by two rudiments. An anterior rudiment and a posterior rudiment. Sulcus Terminalis mark the union of these rudiments.


3. Functions.

Functions of the tongue are listed below :

  • Taste.
  • Speech.
  • Deglutition.
  • Mastication.

4.Parts of Tongue:

The superior surface of the body is called dorsal surface or dorsum. The inferior surface of the body is called ventral surface. The dorsum has two parts and is called anterior 2/3rd and posterior 1/3rd. Anterior 2/3rd is called oral part or buccal part and posterior 1/3rd is called pharyngeal part or lymphoid part. These two parts differ developmentally, topographically, in appearance, structurally, histologically, functionally, in nerve and blood supply.

Posterior 1/3rd of tongue forms the anterior wall of pharynx so it is known as pharyngeal part and contains so many lymphoid tissues so it is also known as lymphoid part.

Anterior and posterior part is separated by a “V” Shaped groove called as Sulcus Terminalis. There is a depression in the center of the separation and the depression is called as foramen caecum.


Also Check: BDS Question Papers


5.Mucosal Folds:

There are three mucous folds. They are frenulum linguae or Lingual Frenum and glossoepiglottic folds(One median and two lateral). Frenulum linguae is the vertical folds of mucous membrane connecting the tongue to the floor of the mouth. It separates the opening of the sum-mandibular duct.

Glossoepiglottic Folds: There are one median and two lateral folds. These are folds of the mucous membrane between dorsum of the tongue and anterior surface of epiglottis. Between them, there is a depression is called as vallecula.


6. Nerve Supply.

Anterior 2/3rd by lingual nerve and chorda tympani branch of facial nerve. The Posterior 1/3rd is supplied by glossopharyngeal nerve for sensory and hypoglossal for the motor.


7. Blood Supply.

The tongue receives blood supply from the lingual artery on the floor of the mouth and there is also a secondary blood supply from the tonsillar branch of the facial artery and ascending pharyngeal artery.


8. Lymphatic Drainage.

Lymphatic Drainage is divided into four sets:

  • Apical Sets.
  • Central Sets.
  • Basal Sets.
  • Marginal Sets.

Apical Sets:- From the tip drain into the submental lymph node and suprahyoid lymph node.

Central Sets- Lymph vessels from the upper part drain into the upper deep cervical lymph node.

Basal Sets:- From the posterior end/part drain into the lower deep cervical lymph node.

Marginal Sets:- Lymph vessels from lateral border drains to the submandibular grooves of the lymph node.  


9. Muscles of Tongue.

All the muscles of the tongue are skeletal muscles. There is a midline fibrous septum which divides it into two equal halves i.e right and left halves. Each half contain two sets of muscles, an intrinsic and extrinsic set. Extrinsic sets are those that take origin from sources outside the tongue and inserted into the corresponding sides. Intrinsic muscles are confined to the tongue and both the origin and insertion are within the tongue.

9.1. Extrinsic Muscles.

There are five sets of extrinsic muscles present on each side. Extrinsic muscles are as follows:

  • Genioglossus.
  • Hyoglossus.
  • Chondroglossus.
  • Styloglossus.
  • Palatoglossus.

Genioglossus:

Origin is from the superior genial tubercle of the mandible. The action of this muscle is protraction of tongue. This muscle is called as safety muscle of tongue because when this muscle gets paralyzed the tongue will roll back and closes the laryngeal opening which results in suffocation.

Hyoglossus:

Origin is from the upper part of the body of hyoid bone and greater cornu. It is a depressor muscle which pulls the tongue towards the floor of the mouth.

Chondroglossus:

The lower part of the hyoid bone is called as chondroglossus. This muscle originates from lower part hyoid bone and lesser horn or cornu.

Styloglossus:

Originates from the apical part of the styloid process of temporal bone. It acts as the retractor of the tongue. It helps to withdraw the tongue and also helps raise the posterior part.

Palatoglossus:

Originates from the inferior surface of palatine aponeurosis. It acts as the elevator i.e it helps to raise the tongue.

9.2. Intrinsic Muscles.

There are three sets of intrinsic muscles called as longitudinal, vertical and transverse sets. Intrinsic muscles are arranged in three planes at the right angle to each other.

Longitudinal Set:

It contains superior longitudinal and inferior longitudinal muscles. These muscles extend from the tip to base of the tongue. The vertical lingual muscles are placed between two longitudinal muscles mainly at the tip and the lateral walls.

Transverse Set:

It originates from midline fibrous septum and then runs towards the lateral wall.

Vertical Set:

It lies between two longitudinal muscles. It helps in altering the shape and deviation of the tip of the tongue to one side.

9.3. Nerve Supply of Muscles.

All muscles except palatoglossus are supplied by the hypoglossal nerve which is the 12th cranial nerve. Whereas the palatoglossus is supplied by cranial part of accessory nerve i.e the 11th cranial nerve.

9.4. Blood Supply of Muscles.


Applied Anatomy

When the hypoglossal nerve is paralyzed then the corresponding half of the tongue undergoes atrophy.

This is an article completely about the anatomy of the tongue. I had tried my best to include everything in this chapter. If you have anything else to know please comment it below.

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