Changes

==Introduction==

==Introduction==

==Structure and Function==

==Structure and Function==

The tounge is skeletal muscle dorsally. There is structural fat surrounded by a cartilagenous sheath forming lyssa (canids only) ventrally. There is 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]].

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]]

[[Image:Tongue Anatomy Cow2.jpg|thumb|right|250px|Tongue Anatomy (Cow) - Copyright Nottingham 2008]]

==Muscles==

==Muscles==

===Intrinsic Muscles===

===Intrinsic Muscles===

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

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

===Extrinsic Muscles===

===Extrinsic Muscles===

The extrinsic muscles include;

The extrinsic muscles include:

'''Styloglossus'''

'''Styloglossus'''

The origin is the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] (stylohyoid). It retracts and elevates the tongue.

Its origin is at the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] (stylohyoid) and it retracts and elevates the tongue.

'''Genioglossus'''

'''Genioglossus'''

The origin is the incisive part of the [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]]. It protrudes and depressed the tongue.

The origin is at the incisive part of the [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]]. It protrudes and depressed the tongue.

'''Hyoglossus'''

'''Hyoglossus'''

The origin is the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] (basihyoid). It retracts and depresses the tongue.

The origin is at the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] (basihyoid). It retracts and depresses the tongue.

'''Geniohyoideus'''

'''Geniohyoideus'''

The origin is 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.

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.

[[Image:Tongue Muscles Drawing.jpg|thumb|right|250px|Drawing of the Extrinsic Muscles of the Tongue - Copyright nabrown]]

[[Image:Tongue Muscles Drawing.jpg|thumb|right|250px|Drawing of the Extrinsic Muscles of the Tongue - Copyright nabrown]]

==Innervation==

==Innervation==

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 lingual branch of the trigeminal ([[Cranial Nerves - Anatomy & Physiology|CN V]]) which is sensory supplying temperature, touch and pain. The chorda tympani of the facial ([[Cranial Nerves - Anatomy & Physiology|CN VII]]) supplies the taste. The caudal 1/3 of the tongue is innervated by the glossopharyngeal ([[Cranial Nerves - Anatomy & Physiology|CN IX]]) providing motor function for taste.

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.

==Vasculature==

==Vasculature==

[[Image:Tongue Histology Cat.jpg|thumb|right|250px|Tongue Histology (Cat) - Copyright RVC 2008]]

[[Image:Tongue Histology Cat.jpg|thumb|right|250px|Tongue Histology (Cat) - Copyright RVC 2008]]

The tounge 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 (taste buds)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.

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.

==Types of Papillae==

==Types of Papillae==

===Foliate===

===Foliate===

8 to 12 papillae in parallel folds, one either side of the tongue midline. Consists of a stratified squamous epithelium, present in the caudal 1/3 of the tongue. There are taste buds, glands and lymphatics present.

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===

===Vallate===

[[Image:Circumvallate Papillae.jpg|thumb|right|250px|Circumvallate Papillae (Goat) - Copyright RVC 2008]]

[[Image:Circumvallate Papillae.jpg|thumb|right|250px|Circumvallate Papillae (Goat) - Copyright RVC 2008]]

There are 3 to 6, often secondary papillae in taste buds. There are broad glands in the caudal 1/3 of tongue. Taste buds and lymphatics are present.

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===

===Fungiform===

Red dots on tongue surface. Consists of keratinised, stratified squamous epithelium and blood vessels. Involved in loss of heat via panting in dogs. Present in the rostral 2/3 of the tongue, taste buds are present.

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.

[[Image:Filoform Papillae Histology.jpg|thumb|right|250px|Filoform Papillae Histology (Cat) - Copyright RVC 2008]]

[[Image:Filoform Papillae Histology.jpg|thumb|right|250px|Filoform Papillae Histology (Cat) - Copyright RVC 2008]]

===Filiform===

===Filiform===

The most numerous. They 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.

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.

==[[Gustatory System - Anatomy & Physiology|Taste Buds]]==

==[[Gustatory System - Anatomy & Physiology|Taste Buds]]==

*Also found on the [[Soft Palate|soft palate]] and [[Pharynx - Anatomy & Physiology|pharynx]] (but sparsely distributed)

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.

 

*Constant cell turnover

 

*Flat, thick cells

 

*Taste hairs (microvilli) pointing though taste pore

 

*Nerves transduce chemical signals into nervous signals

==Species Differences==

==Species Differences==

[[Image:Pig Tongue.jpg|thumb|right|150px|''Pig Tongue'' <br> Pollo 2007, WikiMedia Commons]]

[[Image:Pig Tongue.jpg|thumb|right|250px|''Pig Tongue'' <br> Pollo 2007, WikiMedia Commons]]

===Canine===

===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===

===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===

===Feline===

*Long papillae for grooming so tongue is rough

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

===Porcine===

===Porcine===

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

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

===[[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==

==Links==

[[Tongue - Pathology|Pathology of the tongue]]

Click here for [[Tongue - Pathology|pathology of the tongue]] information.

 

|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]

[[Category:Oral Cavity - Anatomy & Physiology]]

[[Category:Oral Cavity - Anatomy & Physiology]]