The extrinsic muscles of the tongue, a group of muscles that originate outside the tongue but insert into the tongue, play a vital role in the tongue’s movement and function. These muscles include the geniohyoid, which depresses the tongue; the hyoglossus, which depresses and retracts the tongue; the styloglossus, which elevates and retracts the tongue; and the palatoglossus, which elevates the posterior part of the tongue.
Structure of Extrinsic Muscles of Tongue
The tongue is a muscular organ located in the oral cavity, and its movements are controlled by a group of muscles known as the extrinsic muscles of the tongue. These muscles originate outside the tongue and insert into its substance, providing it with the ability to move in various directions.
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Genioglossus Muscle:
- Origin: Mental spine of the mandible
- Insertion: Body of the tongue
- Function: Protrusion and depression of the tongue
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Hyoglossus Muscle:
- Origin: Body and greater horn of the hyoid bone
- Insertion: Lateral border of the tongue
- Function: Depression and retraction of the tongue
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Styloglossus Muscle:
- Origin: Styloid process of the temporal bone
- Insertion: Lateral border of the tongue
- Function: Retraction and elevation of the tongue
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Palatoglossus Muscle:
- Origin: Palate
- Insertion: Lateral border of the tongue
- Function: Elevation of the tongue’s posterior part
Table of Extrinsic Muscles of Tongue:
| Muscle | Origin | Insertion | Function |
|---|---|---|---|
| Genioglossus | Mental spine of mandible | Body of tongue | Protrusion, depression |
| Hyoglossus | Hyoid bone | Lateral border of tongue | Depression, retraction |
| Styloglossus | Styloid process of temporal bone | Lateral border of tongue | Retraction, elevation |
| Palatoglossus | Palate | Lateral border of tongue | Elevation of posterior part |
Innervation:
- All extrinsic tongue muscles are innervated by the hypoglossal nerve (CN XII), except for the palatoglossus muscle, which is innervated by the vagus nerve (CN X).
Function:
- The extrinsic muscles of the tongue work together to control the tongue’s movement, including protrusion, depression, retraction, and elevation.
- These muscles are essential for speech, swallowing, and other oral functions.
Question 1:
What are the functions of the extrinsic muscles of the tongue?
Answer:
– The extrinsic muscles of the tongue are responsible for altering the tongue’s position within the oral cavity.
– They control the tongue’s protrusion, retraction, elevation, depression, and lateral movements.
Question 2:
How do the extrinsic muscles of the tongue aid in speech production?
Answer:
– The extrinsic muscles of the tongue play a crucial role in speech production by altering the tongue’s shape and position.
– They facilitate the formation of various consonant and vowel sounds through precise movements of the tongue against the palate, teeth, or lips.
Question 3:
What is the innervation of the extrinsic muscles of the tongue?
Answer:
– The extrinsic muscles of the tongue are innervated by the hypoglossal nerve (cranial nerve XII).
– The hypoglossal nerve originates from the medulla oblongata and innervates all the extrinsic tongue muscles, except the palatoglossus.
– The palatoglossus muscle is innervated by the vagus nerve (cranial nerve X).
Well, there you have it, folks! We’ve taken a deep dive into the fascinating world of the tongue’s extrinsic muscles, the powerhouses behind all those fancy tongue movements. Thanks for tagging along on this linguistic adventure. But don’t pack your bags just yet! I’ve got plenty more articles in store for you, so be sure to check back later for more linguistic shenanigans. Take care, and keep your tongues wagging!