Tongue - Nerve Supply

Summary

This video explores the complex nerve innervation of the tongue, highlighting its diverse origins. The anterior 2/3 of the tongue is innervated by the lingual nerve for general sensation and chorda tympani for taste, except for the circumvallate papillae. The posterior 1/3 is served by the glossopharyngeal nerve for both sensations. The posteriormost part receives innervation from the internal lingual branch of the vagus nerve. The tongue's musculature, except for the palatoglossus muscle, is innervated by the hypoglossal nerve, with the palatoglossus being an exception due to its origin from the sixth branchial arch.

Takeaways

• 👅 The tongue has different nerve supplies depending on its parts: anterior 2/3, posterior 1/3, and the posterior most part.
• 🧠 The anterior 2/3 of the tongue's sensory supply is via the lingual nerve, a branch of the mandibular division of the trigeminal nerve (CN V).
• 🔟 The posterior 1/3 of the tongue's general sensation is carried by the glossopharyngeal nerve (CN IX).
• 🌐 The posterior most part of the tongue's general and taste sensations are served by the internal lingual branch of the vagus nerve (CN X).
• 👂 Taste sensation for the entire anterior 2/3 of the tongue is carried by the chorda tympani, a branch of the facial nerve (CN VII).
• 👅 The taste sensation for the circumvallate papilla and the posterior 1/3 of the tongue is handled by the glossopharyngeal nerve (CN IX).
• 💪 All muscles of the tongue, except for the palatoglossus, are innervated by the hypoglossal nerve (CN XII), which originates from the occipital myotomes.
• 🗣️ The palatoglossus muscle is an exception; it is innervated by the accessory nerve due to its origin from the mesenchyme of the sixth branchial arch.
• 🌱 The epithelium covering the anterior 2/3 of the tongue originates from the first branchial arch, while the posterior 1/3 comes from the third branchial arch, and the posterior most from the fourth branchial arch.
• 🧐 Understanding the embryological origins of different parts of the tongue helps in remembering their respective nerve supplies.

Q & A

What is the main reason why understanding nerve innervation to the tongue can be confusing?

Understanding nerve innervation to the tongue can be confusing due to the fact that different parts of the tongue have different sources or origins.

What are the three main parts of the tongue mentioned in the script?

The three main parts of the tongue are the body or anterior 2/3, the posterior 1/3, and the posterior most part.

Which branchial arch does the epithelium covering the anterior 2/3 of the tongue originate from?

The epithelium covering the anterior 2/3 of the tongue originates from the first branchial arch.

What nerve is responsible for the general sensation of the anterior 2/3 of the tongue?

The lingual nerve, which is a branch of the mandibular division of the trigeminal nerve (CN V), is responsible for the general sensation of the anterior 2/3 of the tongue.

Which cranial nerve provides general sensation to the posterior 1/3 of the tongue?

The glossopharyngeal nerve (CN IX) provides general sensation to the posterior 1/3 of the tongue.

What nerve carries out general and taste sensations for the posterior most part of the tongue?

The internal lingual branch of the vagus nerve (CN X) carries out both general and taste sensations for the posterior most part of the tongue.

Which nerve is responsible for taste sensation in the anterior 2/3 of the tongue, and what is an exception to this?

The chorda tympani, a branch of the facial nerve (CN VII), is responsible for taste sensation in the anterior 2/3 of the tongue, except for the circumvallate papillae.

What type of muscles does the tongue have, and which cranial nerve innervates them?

The tongue has intrinsic and extrinsic muscles, and all these muscles are innervated by the hypoglossal nerve (CN XII), except for the palatoglossus muscle.

Which muscle of the tongue has a different innervation compared to the others, and what is its innervation source?

The palatoglossus muscle has a different innervation source compared to the other muscles of the tongue; it is innervated by the cranial part of the accessory nerve.

Why is the innervation of the tongue muscles primarily by the hypoglossal nerve?

The muscles of the tongue have their origin from occipital myotomes, hence their innervation is chiefly by the hypoglossal nerve (CN XII).

How does understanding the origin of the tongue's parts help in remembering its innervation?

Understanding the origin of the tongue's parts helps in remembering its innervation because the nerves that supply these parts correspond to the branchial arches from which the parts originate.

Outlines

00:00

👅 Nerve Innovations of the Tongue

This paragraph discusses the complexity of nerve supply to the tongue due to its different parts having distinct origins. The tongue is divided into anterior 2/3, posterior 1/3, and the posteriormost part. The anterior 2/3 has its epithelium from the first branchial arch and is supplied by the lingual nerve, a branch of the trigeminal nerve. The posterior 1/3 and the posteriormost part have their epithelium from the third and fourth branchial arches, respectively, and are innervated by the glossopharyngeal nerve (CN IX) and the internal laryngeal branch of the vagus nerve (CN X). Taste sensation for the anterior 2/3 is provided by the chorda tympani, a branch of the facial nerve, except for the circumvallate papillae. The musculature of the tongue, except for the palatoglossus muscle, is innervated by the hypoglossal nerve (CN XII), which originates from the occipital myotomes. The palatoglossus muscle is an exception, being innervated by the accessory nerve due to its origin from the sixth branchial arch.

05:00

📝 Summary of Tongue's Nerve Innovations

The second paragraph summarizes the nerve supply to the tongue. For the anterior 2/3, the lingual nerve provides general sensation and the chorda tympani provides taste sensation, except for the circumvallate papillae. The glossopharyngeal nerve (CN IX) innervates the general and taste sensations of the posterior 1/3 and the posteriormost part of the tongue, including the circumvallate papillae. The internal laryngeal branch of the vagus nerve (CN X) also supplies the posteriormost part. All muscles of the tongue, except for the palatoglossus, are innervated by the hypoglossal nerve (CN XII). The palatoglossus muscle is innervated by the cranial part of the accessory nerve due to its origin from the sixth branchial arch. Understanding the origin of the tongue's parts helps in remembering their respective nerve supply.

Keywords

💡Nerve Innovation

Nerve innovation refers to the process by which nerves develop and extend to innervate specific body parts. In the context of the video, nerve innovation to the tongue is discussed, which is crucial for understanding how different parts of the tongue receive sensory and motor input. The video explains how the tongue's various regions are innervated by different nerves, reflecting the tongue's complex embryological origins.

💡Tongue

The tongue is a muscular organ in the mouth used for various functions including taste, swallowing, and speech. The video script delves into the tongue's anatomy, focusing on the different parts such as the anterior two-thirds and the posterior one-third, each with distinct nerve supply and functions. Understanding the tongue's structure is key to grasping the video's exploration of nerve innovation.

💡Branchial Arches

Branchial arches are embryonic structures that give rise to various structures in the head and neck, including parts of the tongue. The video mentions the first, third, and fourth branchial arches, which contribute to the development of the tongue's epithelium. This concept is central to understanding why different parts of the tongue have different nerve innervations.

💡Epithelium

Epithelium is the outermost layer of cells covering the body's surfaces, including the tongue. The video script explains that the epithelium of the anterior two-thirds of the tongue originates from the first branchial arch, while the posterior one-third comes from the third arch, and the posteriormost part from the fourth arch. This information is vital for comprehending the nerve supply to the tongue.

💡Lingual Nerve

The lingual nerve is a branch of the mandibular division of the trigeminal nerve (CN V) and is responsible for the sensory supply to the anterior two-thirds of the tongue. The video emphasizes the role of the lingual nerve in conveying general sensations from this part of the tongue, illustrating the specific nerve innovation patterns.

💡Glossopharyngeal Nerve

The glossopharyngeal nerve (CN IX) is highlighted in the video as the nerve responsible for general and taste sensations in the posterior one-third of the tongue. This nerve's role is crucial for understanding the sensory functions of the tongue's posterior region.

💡Vagus Nerve

The vagus nerve (CN X) is discussed in relation to the internal laryngeal branch, which provides general and taste sensations to the posteriormost part of the tongue. The video script uses this nerve as an example of how the most posterior tongue region receives its sensory input.

💡Taste Sensations

Taste sensations are the perceptions of different flavors and are mediated by specific nerves. The video script distinguishes between general and taste sensations, noting that the chorda tympani, a branch of the facial nerve (CN VII), is responsible for taste sensations in the anterior two-thirds of the tongue, except for the circumvallate papillae.

💡Intrinsic and Extrinsic Muscles

Intrinsic muscles are those entirely within an organ, while extrinsic muscles connect an organ to other structures. The video explains that all muscles of the tongue, both intrinsic and extrinsic, are innervated by the hypoglossal nerve (CN XII), except for the palatoglossus muscle, which is innervated differently due to its unique origin.

💡Hypoglossal Nerve

The hypoglossal nerve (CN XII) is responsible for innervating the muscles of the tongue, as discussed in the video. This nerve's role is essential for understanding the tongue's motor functions, as it originates from the occipital myotomes, which are crucial for the tongue's development.

💡Palatoglossus Muscle

The palatoglossus muscle is an extrinsic muscle of the tongue that is innervated by the accessory nerve, as mentioned in the video. This muscle is an exception to the general rule that all tongue muscles are innervated by the hypoglossal nerve, highlighting the complexity and variability in nerve innovation.

Highlights

Different parts of the tongue have different sources or origins, which can be confusing.

The body or anterior 2/3 of the tongue is distinct from the posterior 1/3 and the posterior most part in terms of nerve supply.

The epithelium covering the anterior 2/3 of the tongue originates from the first branchial arch.

The posterior 1/3 of the tongue's epithelium has its origin from the third branchial arch.

The epithelium of the posterior most part of the tongue comes from the fourth branchial arch.

Each branchial arch has its own respective nerve, muscle, and blood vessel.

The sensory supply for the anterior 2/3 of the tongue is by the lingual nerve, a branch of the mandibular division of the trigeminal nerve.

The general sensation for the posterior 1/3 of the tongue is carried by the glossopharyngeal nerve, the ninth cranial nerve.

The general and taste sensations for the posterior most part of the tongue are carried by the internal lingual branch of the vagus nerve, the tenth cranial nerve.

Taste sensation for the entire anterior 2/3 of the tongue is carried by the chorda tympani, a branch of the facial nerve.

The circumvallate papillae are an exception, with taste sensation carried by the glossopharyngeal nerve.

The tongue is composed of intrinsic and extrinsic muscles, all innervated by the hypoglossal nerve, the twelfth cranial nerve.

Palatoglossus muscle is an exception, innervated by the accessory nerve due to its origin from the sixth branchial arch.

Understanding the origin of tongue parts helps in remembering their respective nerve innervations.

The nerve supply to the tongue is essential for both general and taste sensations.

The video provides a comprehensive overview of the tongue's nerve innervation, which is crucial for medical and dental professionals.

Transcripts

[Music]

[Laughter]

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hi in this video I'll be discussing

about nerve Innovation to tongue the

reason why this topic is bit confusing

in complex is because of the fact that

different parts of tongue have different

sources or origin so once we understand

or Trace out the origin of different

parts of tongue including its

musculature it will be easier for us to

remember or understand the nerve

Innovation to tongue so before going

into the details let's briefly look into

the parts of a tongue we have this body

or anterior 2/3 of tongue we have this

posterior 1/3 of tongue and the

posterior most part of the tongue the

epithelium covering the entire tongue

has different sources or origin the

epithelium covering the anterior 2/3 of

tongue has its origin from the first

branchial Arch whereas the epithelium

covering the posterior 1/3 has its

origin from the third bran Arch and the

epithelium covering the posterior most

has its origin from fourth bran

Arch so as we all know each bran Arch

has its own respective nerve has its own

respective muzzle has its own respective

blood vessel so depending upon the

origin of these parts of epithelium from

the respective bran arches we have

different Innovations so now let's

briefly look into the nerve innovation

of

tongue for the anterior 2/3 of tongue

sensory Supply is bil lingual

nerve so this lingual nve is a branch of

mandibular division of trial n and for

the posterior

1/3 that is for this area the general

sensation is carried out by glossop

ferial nerve which is a ninth cranial

nerve and for the poster most part of

the tongue the general sensation is

carried out by

internal lingal

branch of

Vegas which is a 10th cranial n so in

brief the general Sensations for the

anterior 2/3 is by the lingual n which

is a branch of trial n and for the

posterior 1/3 General sensation is by

glossop fenial nve and for the posterior

most part the general sensation is by

internal lenel branch of vas now now

coming to taste sensations we have an

exception here for the anterior 2/3 of

the tongue so for this entire area the T

sensation is carried out by Corda

tan so this Corda tempany is a branch of

facial no so in the anterior 2/3 tast

sensation is carried out by C impan any

except for this circum valent

papillo for the posterior one/ thir of

the tongue the test sensation is carried

out by the

same glossop ferial nerve including

circum valet papillar so for this

posterior 1/3 test sensation is carried

out by the same n which carries out

General Sensations that is gloss ofel no

including the circum valent

papilla and for the posteriormost part

of the town The Taste sensation as well

as the general Sensations are carried

out by the same internal lenial branch

of vas snow so these are in brief about

the general Sensations and taste

sensations of the entire tongue so apart

from this we have musculature as tongue

is a soft organ without any bones it is

made up of two types of muscles broadly

that is intrinsic musles as well as

extrinsic

muscles so all muscles of tongue are

inated by hypoglossal

nerve so the musles of tongue are

innervated by hypoglossal nerve that is

a 12th cranial nerve because these

muscles have their origin from occipital

myotomes so since the muzzles of tongue

have their origin from oxital my

their ination is chiefly by the hypogen

L however we have an exception here

except for one muzzle one extrinsic

muszle that is palatoglossus whose

inovation is mainly by

the accessory nve so palatoglossus no

has its Innovation from cranial part of

accessory no because it has its origin

from the mism of sixth banul

Arch so this is in brief the innovation

of the entire tongue to

summarize the epithelium of tongue has

its Innovations depending upon the part

it is located in for the anterior 2/3

the general sensation is by the lingual

nve that is the branch of mandibular

division of trial no whereas The Taste

sensation is by the cordan which is a

branch of facial no except for circum

valent papilla so this circum valent

papilla along with posterior 1/ thir of

tongue are innervated by glossop fenial

no or ninth cranial no and the posterior

most part of the tongue has its General

and taste sensations derived from

internal lingal branch of vas sow and

coming to the muscul all the muscles of

tongue have their origin from oxital

myotomes hence inovated by hypoglossal n

except for palatoglossus whose origin is

from the mism of six bran AR hence It Is

inovated by the cranial part of

accessory no so once you understand the

origin of any part of tongue it will be

easier for you to remember the

respective

Innovation so this is in brief about a

nerve Innovation to tongue

[Music]

[Laughter]

[Music]

oh

[Music]