Tongue is a muscular organ of animal and important for prehension, mastication and deglutination of food. In the tongue histology, you will find the skeletal muscle that covered by mucosa membrane. Again, the mucosa membrane consists of stratified squamous epithelial lining which may be keratinized or non-keratinized in different parts.
I hope you are looking for the best guide to learn tongue histology with slide pictures. Fine, in this article I am going to discuss on the details histology features of tongue with slide images and labeled diagram. I will show you the different important histological features from the real tongue slide of animals.
You will know the general histological characteristics of animal tongue, connective tissue of tongue and different types of tongue papillae from this article. Again, you will get the list of tongue histology slide identification points.
If you are really interest to learn the histological features of animal tongue then you may continue this article till end.
Tongue histology guide
Before going to the details histological features of tongue I would like to enlist few important structures that you might identify under light microscope.
#1. Surface epithelium (stratified squamous epithelium –keratinized or non-keratinized) of tongue mucosa
#2. Different types of papillae of animal tongue – filliform, fungiform, circumvallate, foliate papillae of tongue surface
#3. Secondary papillae structure from tongue
#4. Lamina propria of tongue
#5. Skeletal muscle fibers (runs in different direction – longitudinal, transverse and per-pendicular)
#6. Different lingual gland of tongue
#7. Taste bud at tongue papillae
Great, let’s find these important structures from the tongue histology slide.
Identification points of tongue histology slide
Do you want to identify the tongue slide under light microscope? Fine, I am going to share the most relavent identification points of tongue histology slide that might help you a lot.
#1. The mucosa membrane of the tissue section showed different projection (commonly known as papillae)
#2. Presence of conical shaped filiform papillae and mushroom shaped fungiform papillae that are lined by keratinized stratified squamous epithelium
#3. The core of the tissue section contains skeletal muscle fibers that run in different direction
#4. Presence of lamina propria in the tissue section that contain three different types of glands (serous, mucous and seromucous) – these gland are actually lingual glands
#5. There are numerous taste buds in the lateral aspect of papillae (circumvallate papillae)
So the provided tissue section is a tongue slide. You may enlist other different possible but relavent identification points for tingue identification.
Animal tongue structures –connective tissue and papillae
The mucosa membrane of tongue at dorsal surface is rough due to presence of different papillae (lingual papillae) and smooth and slippery at ventral surface. In histology of tongue, you will find stratified squamous epithelium on the mucosa of animal tongue. You know, it is keratinized and thick at dorsal part of the tongue and non-keratinized, thin at ventral part of the tongue.
The dorsal surface of tongue have numerous projection like structure called papillae. They are two different types of papillae on tongue – mechanical and gustatory papillae. The mechanical papillae of tongue are – filiform, conical and lenticular and gustatory papillae are – fungiform, vallate and foliate papillae.
These mechanical papillae helps to facilitate the movement of ingesta with the mouth cavity of animal whereas gustatory papillae are responsible for the perception of the sence of taste (as they have taste buds).
I will discuss details of these lingual papillae later in this article; if you want to know the histological features of these papillae from tongue histology then continue this article.
Below the mucosa membrane of tongue you will find the lamina propria that contain loose connective tissue and also contains three different types of glands – seromucous, serous glands and mucous glands. These glands at lamina propria are known as lingual glands.
The core of tongue consists of skeletal muscles (lingual muscles) that run longitudianally, transversely and perpendicular arrangement. These arrangement of skeletal muscles of tongue are responsible for extensive movement of tongue within oral cavity.
The ventral surface of tongue is smooth and covered by stratified squamous nonkeratinized epithelium.
Tongue papillae structure and types
The filiform papillae is numerous types and slender, threadlike structure that project above the surface of the tongue. Filiform pappilae of animal tongue lines with keratinized stratified squamous epithelium with a thick stratum corneum.
In ruminant, you will find the conical shaped projection from the surface of tongue contains keratinized stratified squamous epithelium and connective tissue core with several secondary papillae. Cat have larger filiform papillae on their tongue surface.
The conical papillae found on the root of the tongue of different animals like dog, cat and pig; and on the torus linguae of ruminant tongue. These conical papillae are larger than the filiform papillae and not highly keratinized.
In ruminant tongue (at torous linguae), you will also find the flatten, lens shaped projection (known as lenticular papillae) on the dorsal surface of tongue histology. There are dense connective tissue core and covered by keratinized stratified squamous epithelium on lenticular papillae.
In tongue histology slide, you will also found the dome shaped or mushroom shaped (vary in animals) fungiform papillae that scatterly distrinuted amoung filiform papillae. These papillae lines with nonkeratinized epithelium and contain taste buds. The taste buds of fungiform papillae are less in number in cattle and horse tongue; but more in dog, sheep and goat tongue.
Vallate papillae are large and flatten structure and contain tase buds in different animal’s tongue. Again, the foliate papillae are cylindrical in shaped and located at the caudal part of lateral margin of dorsum of tongue.
Taste buds in tongue papillae
Taste buds are the ellipsoid cluster of specialized epithelial cells that founds in the surface epithelium of different papillae of tongue (especially on fungiform, vallate and foliate papillae).
Actually teaste bud consists of cluster of spindle shaped epithelial cells that extends from the basement membrane to the small opening at the epithelial surface.
In most of the animal you will find three types of cell in taste bud of tongue papillae and they are – type I (sustenticular or supportive cells), type II (gustatory cells taste cells) and type III (basal or steam cells).
#1. Taste cells of gustatory cells of taste bud
These cells are lightly stained and having microvilia at the apical ends. You will also find the unmyelinated nerve fibers in this taste cells of taste bud.
#2. Sustenticular or supportive cells of taste bud
Darkly stained elongated cells that have microvilli at the apical part of cells and provide support to the taste cells of taste bud of tongue.
#3. Basal or steam cells of taste bud
These are the small pyramidal type cells that lying close to the basement membrane and give rise to taste and supportive cells of taste bud.
Tongue histology drawing
Do you want the tongue histology drawing guideline? Well, I am going to share the drawing of tongue structure with you. You might try to draw this tongue structure better.
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