Difference between revisions of "Tongue - Anatomy & Physiology"

Latest revision as of 19:19, 27 October 2022

Introduction

The tongue (lingua) occupies the ventral aspect of the oral cavity and oropharynx. It is involved with grooming, lapping, prehension and manipulating food in the oral cavity. It is also involved in the deglutition reflex and vocalisation. The tongue is capable of vigorous and precise movements due to the apex being free of attachments to the oral cavity.

Tongue Anatomy (Cow) - Copyright Nottingham 2008

Structure and Function

The tongue is skeletal muscle dorsally and structural fat surrounded by a cartilagenous sheath forming lyssa (canids only) ventrally. It has an attached root and body with a free apex. The frenulum (fold of mucosa) attaches the body of the tongue to the floor of the oral cavity. The root of tongue is attached to the hyoid bone. In the horse and dog, the tongue is 'u' shaped, becoming broader towards the tip. The furrow in the centre of the canid tongue is called the median sulcus. In the ox, sheep and pig the tongue is 'v' shaped with a pointed apex. The torus linguae is a swelling across the tongue laterally which pushes food against the hard palate.

Tongue Anatomy (Cow) - Copyright Nottingham 2008

Muscles

Venous Drainage of the Tongue - Copyright Prof. Pat Mccarthy

Intrinsic Muscles

Intrinsic muscles include the dorsal and ventral longitudinal muscles and the transverse and vertical bundles.

Extrinsic Muscles

The extrinsic muscles include:

Styloglossus

Its origin is at the hyoid apparatus (stylohyoid) and it retracts and elevates the tongue.

Genioglossus

The origin is at the incisive part of the mandible. It protrudes and depressed the tongue.

Hyoglossus

The origin is at the hyoid apparatus (basihyoid). It retracts and depresses the tongue.

Geniohyoideus

It originates at the incisive part of the mandible and the insertion site is the body of the hyoid. It lies below the tongue (not within it) and draws the hyoid and therefore the tongue forward.

Drawing of the Extrinsic Muscles of the Tongue - Copyright nabrown

Innervation

All muscles moving the tongue are innervated by the hypoglossal nerve (CN XII). The rostral 2/3 of the tongue is innervated by the sensory lingual branch of the trigeminal (CN V) transmitting temperature, touch and pain sensation. The chorda tympani of the facial nerve (CN VII) transmits the taste. The caudal 1/3 of the tongue is innervated by the glossopharyngeal (CN IX) providing sensory function for taste.

Vasculature

The main blood supply to the tongue is via the lingual artery, a branch of the external carotid artery. A secondary blood supply to the tongue is provided via the tonsillar branch of the facial artery and the ascending pharyngeal artery.

Histology

Tongue Histology (Cat) - Copyright RVC 2008

The tongue consists of stratified squamous epithelium. There are lingual glands and a mucosal covering tightly adheres to the contact surface. The degree of keratinisation depends on the diet. There is less keratinisation on the ventral surface and sides of tongue. It is covered by papillae for protection and taste. Papillae are specialised projections of the mucosa. Some papillae have taste buds, others are mechanical to roughen the surface of the tongue.

Types of Papillae

Conical

Conical papillae are not found in horses. They are present in the caudal 1/3 of the tongue. They point caudally and have no taste buds. There is a thick epithelium.

Foliate Papillae (Cat) - Copyright RVC 2008

Foliate

Eight to twelve papillae in parallel folds, one either side of the tongue midline. Consists of a stratified squamous epithelium, present in the caudal third of the tongue. There are taste buds, glands and lymphatics present.

Vallate

Circumvallate Papillae (Goat) - Copyright RVC 2008

There are three to six, often secondary papillae in taste buds. There are broad glands in the caudal 1/3 of tongue. Taste buds and lymphatics are present.

Fungiform

They form the red dots on tongue surface and consist of keratinised, stratified squamous epithelium and blood vessels. They are involved in loss of heat via panting in dogs. They are present in the rostral 2/3 of the tongue and contain taste buds.

Filoform Papillae Histology (Cat) - Copyright RVC 2008

Filiform

Filiform papillae are the most numerous and point caudally. There are no taste buds, glands or lymphatics. They are the smallest and consist of a thick keratin on stratified squamous epithelium. They are very prominent in cat and are present in the rostral 2/3 of the tongue.

Taste Buds

Also found on the soft palate and the pharynx (but sparsely distributed). There is a constant cell turnover, with flat, thick cells. There are taste hairs (microvilli) pointing through the taste pore. Nerves transduce chemical signals into nervous signals.

Species Differences

Pig Tongue
Pollo 2007, WikiMedia Commons

Canine

There are stretch receptors in the tongue and they use the tongue to lose heat by panting.

Ruminant

The tongue is heavily keratinised with long papillae for eating (protective surface). The ox has lenticular papillae which are hard and horny due to heavy keratinisation.

Feline

Feline species have long papillae for grooming, so their tongue is rough.

Porcine

Most of the papillae are soft, long and directed caudally.

Avian

The avian tongue contains a bone and is mainly used for manipulation of food rather than vocalisation like in mammals. Parrots use the tongue to produce human sounds (see species differences in syrinx)

Links

Click here for pathology of the tongue information.

Tongue - Anatomy & Physiology Learning Resources
Vetstream To reach the Vetstream content, please select	Canis, Felis, Lapis or Equis
Flashcards Test your knowledge using flashcard type questions	Tongue Anatomy & Physiology Flashcards Facial Muscles
Videos Selection of relevant videos	Ventral muscles of the head potcast Lateral surface of the head of the dog potcast Lateral surface and sagittal section of the head of a sheep Lateral surface of the head of the dog potcast 5
PowerPoint Selection of relevant PowerPoint tutorials	Histology of the oral cavity, see part 1 for the tongue
OVAM Anatomy Museum Resources	Image - Cat Tongue

Webinars

Failed to load RSS feed from https://www.thewebinarvet.com/gastroenterology-and-nutrition/webinars/feed: Error parsing XML for RSS

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-|linktext =Alimentary System
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-<br>
 ==Introduction==
-The tongue (lingua) occupies the ventral aspect of the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]] and [[Oral Cavity - Oropharynx - Anatomy & Physiology|oropharynx]]. It is involved with grooming, lapping, prehension and manipulating food in the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]. It is also involved in the [[Deglutition|deglutition]] reflex and vocalisation.
+The tongue (lingua) occupies the ventral aspect of the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]] and [[Oropharynx - Anatomy & Physiology|oropharynx]]. It is involved with grooming, lapping, prehension and manipulating food in the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]. It is also involved in the [[Deglutition|deglutition]] reflex and vocalisation. The tongue is capable of vigorous and precise movements due to the apex being free of attachments to the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]].
+[[Image:Tongue Anatomy Cow.jpg|thumb|right|250px|Tongue Anatomy (Cow) - Copyright Nottingham 2008]]
-The tongue is capable of vigorous and precise movements due to the apex being free of attachments to the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]].
-[[Image:Tongue Anatomy Cow.jpg|thumb|right|150px|Tongue Anatomy (Cow) - Copyright Nottingham 2008]]
 ==Structure and Function==
-*Skeletal muscle dorsally
+The tongue is skeletal muscle dorsally and structural fat surrounded by a cartilagenous sheath forming lyssa (canids only) ventrally. It has an attached root and body with a free apex. The '''frenulum''' (fold of mucosa) attaches the body of the tongue to the floor of the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]. The root of tongue is attached to the [[Hyoid Apparatus - Anatomy & Physiology|hyoid bone]]. In the horse and dog, the tongue is 'u' shaped, becoming broader towards the tip. The furrow in the centre of the canid tongue is called the '''median sulcus'''. In the ox, sheep and pig the tongue is 'v' shaped with a pointed apex. The '''torus linguae''' is a swelling across the tongue laterally which pushes food against the [[Hard Palate|hard palate]].
+[[Image:Tongue Anatomy Cow2.jpg|thumb|right|250px|Tongue Anatomy (Cow) - Copyright Nottingham 2008]]
-*Structural fat surrounded by cartilagenous sheath forming lyssa (canids only) ventrally
+==Muscles==
+[[Image:Tongue Venous Drainage.jpg|thumb|right|250px|Venous Drainage of the Tongue - Copyright Prof. Pat Mccarthy]]
-*Attached root and body with a free apex
+===Intrinsic Muscles===
-*Frenulum (fold of mucosa) attaches the body of the tongue to the floor of the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]
+Intrinsic muscles include the dorsal and ventral longitudinal muscles and the transverse and vertical bundles.
-*Root of tongue attached to [[Hyoid Apparatus - Anatomy & Physiology|hyoid bone]]
+===Extrinsic Muscles===
-*In the horse and dog the tongue is 'u' shaped, becoming broader towards the tip. The furrow in the centre of the canid tongue is called the median sulcus.
+The extrinsic muscles include:
-*In the ox, sheep and pig the tongue if 'v' shaped with a pointed apex. The torus linguae is a swelling across the tongue laterally which pushes food against the [[Hard Palate - Anatomy & Physiology|hard palate]].
+'''Styloglossus'''
-[[Image:Tongue Anatomy Cow2.jpg|thumb|right|150px|Tongue Anatomy (Cow) - Copyright Nottingham 2008]]
-==Muscles==
+Its origin is at the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] (stylohyoid) and it retracts and elevates the tongue.
-'''Intrinsic Muscles'''
+'''Genioglossus'''
-*The dorsal and ventral longitudinal
+The origin is at the incisive part of the [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]]. It protrudes and depressed the tongue.
-* Transverse and vertical bundles
+'''Hyoglossus'''
-'''Extrinsic Muscles'''
+The origin is at the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] (basihyoid). It retracts and depresses the tongue.
-*Styloglossus
+'''Geniohyoideus'''
-**Origin: [[Hyoid Apparatus - Anatomy & Physiology|Hyoid apparatus]] (stylohyoid)
-**Retracts and elevates tongue
-[[Image:Tongue Venous Drainage.jpg|thumb|right|150px|Venous Drainage of the Tongue - Copyright Prof. Pat Mccarthy]]
-*Genioglossus
-**Origin: Incisive part of [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]]
-**Protrudes and depressed tongue
-*Hyoglossus
+It originates at the incisive part of the [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]] and the insertion site is the body of the [[Hyoid Apparatus - Anatomy & Physiology|hyoid]]. It lies below the tongue (not within it) and draws the [[Hyoid Apparatus - Anatomy & Physiology|hyoid]] and therefore the tongue forward.
-**Origin: [[Hyoid Apparatus - Anatomy & Physiology|Hyoid apparatus]] (basihyoid)
-**Retracts and depresses tongue
-*Geniohyoideus
+[[Image:Tongue Muscles Drawing.jpg|thumb|right|250px|Drawing of the Extrinsic Muscles of the Tongue - Copyright nabrown]]
-**Origin: Incisive part of [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]]
-**Insertion: Body of [[Hyoid Apparatus - Anatomy & Physiology|hyoid]]
-**Lies below the tongue (not within it)
-**Draws the [[Hyoid Apparatus - Anatomy & Physiology|hyoid]] and therefore the tongue forward
-[[Image:Tongue Muscles Drawing.jpg|thumb|right|150px|Drawing of the Extrinsic Muscles of the Tongue - Copyright nabrown]]
 ==Innervation==
-*All muscles moving the tongue are innervated by the hypoglossal nerve ([[Cranial Nerves - Anatomy & Physiology|CN XII]])
+All muscles moving the tongue are innervated by the hypoglossal nerve ([[Cranial Nerves - Anatomy & Physiology|CN XII]]). The rostral 2/3 of the tongue is innervated by the sensory lingual branch of the trigeminal ([[Cranial Nerves - Anatomy & Physiology|CN V]]) transmitting temperature, touch and pain sensation. The chorda tympani of the facial nerve ([[Cranial Nerves - Anatomy & Physiology|CN VII]]) transmits the taste. The caudal 1/3 of the tongue is innervated by the glossopharyngeal ([[Cranial Nerves - Anatomy & Physiology|CN IX]]) providing sensory function for taste.
-*Rostral 2/3 of tongue is innervated by the lingual branch of trigeminal ([[Cranial Nerves - Anatomy & Physiology|CN V]]) which is sensory supplying temperature, touch and pain. The chorda tympani of facial ([[Cranial Nerves - Anatomy & Physiology|CN VII]]) supplies the taste.
-*The caudal 1/3 of tongue is innervated by the glossopharyngeal ([[Cranial Nerves - Anatomy & Physiology|CN IX]]) providing motor function for taste.
 ==Vasculature==
-*The main blood supply to the tongue is via the lingual artery- a branch of the external carotid artery
+The main blood supply to the tongue is via the '''lingual artery''', a branch of the external carotid artery. A secondary blood supply to the tongue is provided via the tonsillar branch of the facial artery and the ascending pharyngeal artery.
-*A secondary blood supply to the tongue is provided via the tonsillar branch of the facial artery and the ascending pharyngeal artery
 ==Histology==
+[[Image:Tongue Histology Cat.jpg|thumb|right|250px|Tongue Histology (Cat) - Copyright RVC 2008]]
-[[Image:Tongue Histology Cat.jpg|thumb|right|150px|Tongue Histology (Cat) - Copyright RVC 2008]]
+The tongue consists of stratified squamous epithelium. There are [[Lingual Gland - Anatomy & Physiology|lingual]] glands and a mucosal covering tightly adheres to the contact surface. The degree of keratinisation depends on the diet. There is less keratinisation on the ventral surface and sides of tongue. It is covered by papillae for protection and taste. Papillae are specialised projections of the mucosa. Some papillae have taste buds, others are mechanical to roughen the surface of the tongue.
-*Stratified squamous epithelium
-*[[Lingual Gland - Anatomy & Physiology|Lingual]] glands
-*Mucosal covering tightly adheres to the contact surface
-*Degree of keratinisation depends on diet
-*Less keratinisation on ventral surface and sides of tongue
-*Covered by papillae (taste buds)for protection and taste
-*Papillae are specialised projections of the mucosa
-*Some papillae have taste buds others are mechanical to roughen surface of tongue
 ==Types of Papillae==
 ===Conical===
-*Not in horses
+Conical papillae are not found in horses. They are present in the caudal 1/3 of the tongue. They point caudally and have no taste buds. There is a thick epithelium.
-*Caudal 1/3 of tongue
-*Point caudally
+[[Image:Foliate_Papillae_Cat.jpg|thumb|right|250px|Foliate Papillae (Cat) - Copyright RVC 2008]]
-*No taste buds
-*Thick epithelium
-[[Image:Foliate_Papillae_Cat.jpg|thumb|right|150px|Foliate Papillae (Cat) - Copyright RVC 2008]]
 ===Foliate===
-*8 to 12 papillae in parallel folds, one either side of tongue midline
+Eight to twelve papillae in parallel folds, one either side of the tongue midline. Consists of a stratified squamous epithelium, present in the caudal third of the tongue. There are taste buds, glands and lymphatics present.
-*Stratified squamous epithelium
-*Caudal 1/3 of tongue
-*Taste buds present
-*Glands
-*Lymphatics present
 ===Vallate===
-[[Image:Circumvallate Papillae.jpg|thumb|right|150px|Circumvallate Papillae (Goat) - Copyright RVC 2008]]
+[[Image:Circumvallate Papillae.jpg|thumb|right|250px|Circumvallate Papillae (Goat) - Copyright RVC 2008]]
-*3 to 6
+There are three to six, often secondary papillae in taste buds. There are broad glands in the caudal 1/3 of tongue. Taste buds and lymphatics are present.
-*Often secondary papillae in taste buds
-*Broad glands
-*Caudal 1/3 of tongue
-*Taste buds present
-*Lymphatic tissue present
 ===Fungiform===
-*Red dots on tongue surface
+They form the red dots on tongue surface and consist of keratinised, stratified squamous epithelium and blood vessels. They are involved in loss of heat via panting in dogs. They are present in the rostral 2/3 of the tongue and contain taste buds.
-*Keratinised, stratified squamous epithelium
-*Blood vessels
+[[Image:Filoform Papillae Histology.jpg|thumb|right|250px|Filoform Papillae Histology (Cat) - Copyright RVC 2008]]
-*Loss of heat via panting in dogs
-*Rostral 2/3 of tongue
-*Taste buds present
-[[Image:Filoform Papillae Histology.jpg|thumb|right|150px|Filoform Papillae Histology (Cat) - Copyright RVC 2008]]
 ===Filiform===
-*Most numerous
+Filiform papillae are the most numerous and point caudally. There are no taste buds, glands or lymphatics. They are the smallest and consist of a thick keratin on stratified squamous epithelium. They are very prominent in cat and are present in the rostral 2/3 of the tongue.
-*Points caudally
-*No taste buds
-*No glands
-*No lymphatics
-*Smallest
-*Thick keratin on stratified squamous epithelium
-*Very prominent in cat
-*Rostral 2/3 of tongue
-==Taste Buds==
-*Also found on the [[Soft Palate - Anatomy & Physiology|soft palate]] and [[Pharynx - Anatomy & Physiology|pharynx]] (but sparsely distributed)
-*Constant cell turnover
-*Flat, thick cells
-*Taste hairs (microvilli) pointing though taste pore
+==[[Gustatory System - Anatomy & Physiology|Taste Buds]]==
-*Nerves transduce chemical signals into nervous signals
+Also found on the [[Soft Palate|soft palate]] and the [[Pharynx - Anatomy & Physiology|pharynx]] (but sparsely distributed). There is a constant cell turnover, with flat, thick cells. There are taste hairs (microvilli) pointing through the taste pore. Nerves transduce chemical signals into nervous signals.
 ==Species Differences==
-[[Image:Pig Tongue.jpg|thumb|right|150px|Pig Tongue - Copyright Pollo]]
+[[Image:Pig Tongue.jpg|thumb|right|250px|''Pig Tongue'' <br> Pollo 2007, WikiMedia Commons]]
 ===Canine===
-*Stretch receptors in the tongue
+There are stretch receptors in the tongue and they use the tongue to lose heat by panting.
-*Uses the tongue to lose heat by panting
 ===Ruminant===
-*Tongue is heavily keratinised with long papillae for eating (protective surface)
+The tongue is heavily keratinised with long papillae for eating (protective surface). The ox has lenticular papillae which are hard and horny due to heavy keratinisation.
-*Ox has lenticular papillae which are hard and horny due to heavy keratinisation
 ===Feline===
-*Long papillae for grooming so tongue is rough
+Feline species have long papillae for grooming, so their tongue is rough.
 ===Porcine===
-*Most of the papillae are soft, long and directed caudally
+Most of the papillae are soft, long and directed caudally.
-===[[The Avian Tongue - Anatomy & Physiology|Avian]] ===
+===[[Avian Tongue - Anatomy & Physiology|Avian]] ===
-*There is a bone present
+The avian tongue contains a bone and is mainly used for manipulation of food rather than vocalisation like in mammals. Parrots use the tongue to produce human sounds (see [[Syrinx - Anatomy & Physiology#Species differences|species differences in syrinx]])
-*It is mainly used for manipulation of food rather than vocalisation like in mammals
-*Parrots use the tongue to produce human sounds (see [[Syrinx - Anatomy & Physiology#Species differences|here]])
 ==Links==
-[[Oral Cavity - Anatomy & Physiology - Flashcards#Tongue Flashcards|Tongue Flashcards]]
+Click here for [[Tongue - Pathology|pathology of the tongue]] information.
+<br>
+{{Learning
+|flashcards= [[Tongue Anatomy & Physiology Flashcards]]<br>[[Facial_Muscles_-_Musculoskeletal_-_Flashcards|Facial Muscles]]
+|powerpoints= [[Oral Cavity Histology resource|Histology of the oral cavity, see part 1 for the tongue]]
+|videos = [[Video: Ventral muscles of the head potcast|Ventral muscles of the head potcast]]<br>[[Video: Lateral surface of the head of the dog potcast|Lateral surface of the head of the dog potcast]]<br>[[Video: Lateral surface and sagittal section of the head of a sheep|Lateral surface and sagittal section of the head of a sheep]]<br>[[Video: Lateral surface of the head of the dog potcast 5|Lateral surface of the head of the dog potcast 5]]
+|OVAM = [http://www.onlineveterinaryanatomy.net/content/cat-tongue Image - Cat Tongue]
+|Vetstream = [https://www.vetstream.com/canis/Content/Disease/dis00702.asp Macroglossia]
+}}
-[[Tongue - Pathology|Pathology of the tongue]]
+==Webinars==
+<rss max="10" highlight="none">https://www.thewebinarvet.com/gastroenterology-and-nutrition/webinars/feed</rss>
+[[Category:Oral Cavity - Anatomy & Physiology]]