Where is papillae found

On the dorsal, anterior border of the tongue are mushroom shaped papillae, fungiform, these have taste buds located near the middle or in a cleft of the papillae. Taste buds are also located in the oral mucosa of the palate and epiglottis.

The taste cells are modified epithelial cells that function as sensory receptors. About taste cells are located in pear-shaped taste buds and the taste cells through microvilli project into a taste pore.

There are non-receptor basal cells which are located on the basement membrane which do not project into the taste pore. These basal cells differentiate through a series of morphological steps into a mature taste cell. The taste cells are replaced about every 10 days. Transduction of chemical stimuli into nerve impulses begins with saliva transporting the dissolved polar molecules that are sweet or bitter i.

Polar molecules do not enter the taste cells, but bind to receptors on the microvilli in the taste pore. An action potential is then generated in the afferent nerve ending and conducted by the stimulated cranial nerve into the CNS. A similar transduction process converts non-polar solutes into nerve impulses. A clear understanding of the role of different papillae in the pig may permit the development of a more palatable diet, thus, better utilizing anatomical structures and morphological characteristics to enhance health and productivity in this domestic species.

The study used ten healthy market-size, mixed-breed pigs to properly describe the surface structure of the tongue papillae using standard scanning electron microscopic techniques. Two types of sharp and blunt filiform papillae were identified.

Fungiform papillae, located on the lateral side of the tongue, were circular and large with surface taste pores. Filiform papillae are the most common. They are keratinised and in the living, they look white. Fungiform papillae are not keratinised, but are highly vascularised. In the living, they look red. Underneath the papillae, there are mucous and serous glands, pockets of adipose tissue, and a layer of skeletal muscle and connective tissue. The skeletal muscle is arranged in three different planes, which allows the tongue to perform a number of complex movements.

Now have a look at this section, a vertical section of tongue taken just anterior to the sulcus, that shows part of a circumvallate papilla. See if you can identify Von Ebner's glands, the cleft of the circumvallate papilla, the taste buds, and the muscle layer.