Tongue: structure, papillae, muscles

Tongue is supported caudally by?

Hyoid bone

Tongue consist of?

• Striated muscle

• CT and adipose tissue

• Glands

• Thick mucous membrane

Function of tongue

Important tactile organ by mechanical or taste buds (chemical selection of food)

• Prehension

• Sorting of solid food

• Mastication

• Deglutition

• Delivers insalivated bolus into pharnyx

What are the 5 nerves that innervate the tongue and which is the only motor nerve?

• Mandibular branch of trigeminal nerve (V)

• Facial nerve (VII)

• Glossopharyngeal nerve (IX)

• Vagus nerve (X)

• Hypoglossal nerve (XII, motor nerve)

Structure of Tongue

• Dorsum linguae

• Apex

• Frenulum linguae

• Corpus linguae

• Radix linguae

Dorsum linguae: Upper surface of tongue

Apex: Tip of tongue

Frenulum linguae: Thin membrane fold under tongue

Corpus linguae: Main body

Radix linguae: Back part of tongue that connects to throat

Where is the tongue located?

Lies in the intermanibular space

How is the tongue anchored to mandible and hyoid apparatus?

Extrinsic lingual muscle

Which animals’ body of tongue has extensive lateral surfaces?

Herbivores and pig

Structure specific to ruminants

• Has torus linguae

  • Raised bump at back of tongue

• Fossa linguae

  • Groove infront of it

Structure specific to horse

Has cartilage bar in the middle of tongue

Structure specific to dog

• Has median groove (dorsum)

• Mucous membrane is thin and delicate

Which animals have thick and tough mucosa in their dorsum?

Ruminent and cats

Mucous membrane has numerous?

Papillae

What are the 5 types of tongue papillae?

• Filiform papillae

• Conical and lenticular papillae #ffca00

• Fungiform papillae

• Vallate papillae

• Folliate papillae

Which papillaes are mechanical?

• Filiform papillae

• Conical and lenticular papillae

Which papillaes are gustatory?

• Fungiform papillae

• Vallate papillae

• Folliate papillae

Filiform

• Shape

• Heavily cornified in

• Soft and long in

• Located in radix (back) in only which species

Shape: Soft and horny

Heavily cornified in: Ox and cats

Soft and long in: Carnivores and pigs

Located in radix (back) in only which species: Carnivores and pigs

Conical & Lenticular Papillae

• Location

Location: Scattered among filiform (especially on torus linguae)

Fungiform Papillae

• Location

• Function

Location: Dorsum (upper surface)

Function: Taste buds

Vallate Papillae

• Location

• Pairing in

  • Pigs & house

  • Carnivores

  • Ox

  • Sheep

  • Goat

Location: Dorsum (upper surface)

Pairing in:

• Pigs & house: 1 large pair

• Carnivores: 2-3 pairs

• Ox: 8-17 pairs

• Sheep: 18-24 pairs

• Goat: 12-18 pairs

Foliate Papillae

• Location

• Present in which animals

• Absent in

Location: Border of tongue

Present in: Horse, pig and dog

Absent in: Ruminants

Which 3 papillaes are found in all domestic animals

• Filiform

• Fungiform

• Vallate

What are the 2 types of lingual muscles found in the tongue?

• Intrinsic lingual muscle

• Extrinsic lingual muscle

Intrinsic Lingual Muscle

• Relationship with tongue

• Consist of

• Relationship with skeleton

• Types of directions

• Able to

Relationship with tongue: Bulk of tongue

Consist of: Deep and superficial fibres bundles

Relationship with skeleton: Not attach

Types of directions:

• Longitudinal

• Perpendicular

• Transverse

Able to: Alter shape of tongue

Extrinsic Muscles

• Originate from

• The 3 types

Originates from: Skeleton

3 types:

• Genioglossus:

  • Fan shaped, lies next to median plane and separated by lingual septum

• Hyoglossus:

  • Ventrolateral to tongue

• Styloglossus:

  • Long, slender muscle originates from ventral end of stylohyoid

Masticatory Apparatus

• What are the 3 things that aid in the masticatory aspect of oral cavity

• Teeth and gums

• Temporomandibular & symphysical joint of jaw

• Masticatory muscles

What are the 3 masticatory muscles?

• Temporalis

• Massester

• Pterygoid

Temporalis Muscle

• Function

• Large in

Function: Pulls mandible upwards

Large in: Dog and cats

Massester Muscle

• Function

• Small in

• Better developed in

Function: Raise mandible and draw it towards active side

Small in: Dogs

Better developed in: Herbivores that make lateral and rotational movements when chewing

Pterygoid Muscle

• Location

• Function

Location: Medial to mandible

Function: Raise mandible and draws it inward