Author examined the dorsal lingual surfaces of the adult Japanese lesser flying squirrel (Pteromys momonga) and four-toed hedgehog (Atelerix albiventris) by scanning electron microscopy. In the Japanese lesser flying squirrel, the filiform papilla of the lingual body consisted of a large conical papilla. The filiform papilla of the lingual prominence was spoon in shape. The fungiform papillae were round in shape and scattered among the filiform papillae. Many foliate papillae were observed on the posterolateral regions of the lingual body. The foliate papillae had some ridges separated by deep grooves. The vallate papilla was located between lingual body and root. Several long conical papillae derived from the posterolateral margin of the tongue. In the four-toed hedgehog, the filiform papilla of the lingual apex had a conical process. The filiform papilla of the lingual body had some processes. The fungiform papillae were round in shape. The foliate papillae were observed on the posterolateral regions of the lingual body. The papilla was separated from each other by a furrow. The vallate papilla consisted of a central papilla and an annular pad. These findings suggest that in the structure of the lingual papillae of the Japanese lesser flying squirrel there is similar to that of the sugar glider and the lingual papillae of the four-toed hedgehog is different from that of the Japanese lesser flying squirrel.

We examined the dorsal lingual surfaces of an adult bharal (Pseudois nayaur) by scanning electron microscopy. The filiform papillae of the lingual apex and body consisted of a main papilla and smaller secondary papillae. The filiform papilla of the lingual body was big as compared to that of the lingual apex. The connective tissue cores of the filiform papillae consisted of several processes. The fungiform papilla was round in shape. The connective tissue cores of the fungiform papillae were flower-bud shaped. The lenticular papillae of large size were limited on the lingual prominence. The connective tissue cores of the lenticular papillae were hair-like in shape. The vallate papillae were located on both sides of the posterolateral aspects. The vallate papillae were flattened-oval shaped and the papillae were surrounded by an oval-shaped trench. The connective tissue cores of the vallate papillae were covered with numerous small spines The lingual surface of the bharal closely resembled that of the family Bovidae.

We microscopically examined the dorsal lingual surface of an adult lion-tailed macaque (Macaca silenus). The tongue of the chimpanzee was about 13 cm long. Filiform papillae on the lingual apex consisted of several pointed processes. There were dome-shaped fungiform papillae scattered among the filiform papillae. The connective tissue cores of those filiform papillae consisted of processes of various size, while these of the fungiform papillae had several ditches. The vallate papilla was surrounded by a groove and pad, and were flattened-oval shaped. The connective tissue cores of the vallate papillae were covered with numerous small spines. Many foliate papillae were observed on the posterolateral regions of the tongue. After removing epithelium from the foliate papillae many processes became apparent.

We examined the dorsal lingual surfaces of an adult Chapman's zebra by scanning electron microscopy. The filiform papillae of the lingual apex consisted of a main papilla and smaller secondary papillae. The fungiform papillae were round in shape. The filiform papillae of central region of the lingual body were needle-like in shape. The filiform papillae of posterior region of the lingual body were hair-like in shape. Many grooves were observed on posterolateral regions and the fungiform papillae were observed on the inside of some grooves. The vallate papillae were located on both sides of the posterior region and surrounded by a groove. The anatomical characteristic of the lingual surface of the Chapman's zebra is the fungiform papillae on the inside of some grooves.

We microscopically examined the dorsal lingual surface of an adult chimpanzee (Pan troglodytes). The tongue of the chimpanzee was about 13 cm long. Filiform papillae were distributed over the entire dorsal surface of the lingual body. There were many fungiform papillae scattered among the filiform papillae. At the posterior end of the lingual body, a triangular arrangement of the vallate papillae, with the apex of the triangle directed posteriorly, was observed. The filiform papillae on the lingual apex consisted of a main papilla and secondary papillae. The filiform papillae on the lingual body had several pointed processes. There were dome-shaped fungiform papillae scattered among the filiform papillae. The vallate papillae were surrounded by grooves and were flattened-oval shaped. Many foliate papillae were observed on the posterolateral regions of the tongue.

We examined the dorsal lingual surfaces of a newborn and an old polar bears by using scanning electron microscopy. In the newborn polar bear, the filiform papilla on the lingual apex was cylindrical in shape. The connective tissue core of the filiform papillae was needle-shaped and that of the fungiform papillae was funnel-shaped. The filiform papillae on the lingual body was dome-shaped. The connective tissue core of the filiform papillae was U-shaped and that of the fungiform papillae was column-shaped. On the lingual apex and body, there could not distinguish the filiform from fungiform papillae. The connective tissue core of the filiform papilla was different from the fungiform papilla. The vallate papillae were surrounded by a groove and pad and the surface was smooth. In the old bear, the filiform papilla on the lingual apex had several pointed processes. The processes of the filiform papilla on the lingual body were larger than those of the lingual apex. The vallate papillae were surrounded by a groove and pad and the surface was rough. There are no foliate papillae.

The dorsal lingual surface of the grey crowned crane (Balearica regulorum), American flamingo (Phoenicopterus rubber), great egret (Ardea alba), mallard (Anas platyrhynchos), Himalayan monal (Lophophorus impejanus), black-necked stilt (himantopus mexicanus) and green macaw (Ara militaris) were examined by scanning electron microscopy. In the grey crowned crane, the surface of the lingual apex was relatively rough. Many openings of the lingual glands in both lateral regions of the lingual body were observed. The surfaces of many conical papillae were smooth. Many openings of the lingual glands were observed in the region of the lingual root. In the American flamingo, the surface of the lingual apex was relatively smooth. The surfaces of many fang-like and mustache-like structures were smooth. In the great egret, the surfaces of the lingual apex, central part of the posterior lingual body and giant conical papilla were relatively smooth. Many openings of the lingual glands were observed on the lingual root. In the mallard, the surface of the lingual apex was relatively smooth. The thread-shaped and scale-shaped structures were observed on the anterolateral region of the lingual body. The saw-shaped papillae on the posterolateral region of the lingual body consisted of the thread-shaped structure and big processes. In the Himalayan monal, the dorsal surfaces of the lingual apex and body were relatively smooth. The posterior part of the lingual body consisted of several conical papillae. Many openings of the lingual glands were observed on the lingual root. In the black-necked stilt, the surface of the lingual apex was relatively smooth. The dorsal surface of the lingual body was rough to comparison with that of the lingual apex. The posterior part of the lingual body consisted of several conical papillae. In the green macaw, the surface of the lingual apex had many grooves. The posterior part of the lingual body consisted of several conical papillae. These findings indicate a close correlation between the shape of the tongue and the method of food intake, the type of food, and bird's habitat.

The dorsal surface structure of the lingual papillae in the least weasel was compared with that of other carnivorous mammalian species. Two types of mechanical papillae (filiform and conical) and two types of gustatory papillae (fungiform and vallate) were observed. The filiform papillae had secondary processes. Rarely conical papillae were observed. A few taste buds were seen on the surfaces of the fungiform papillae. The four vallate papillae were located on both sides of the posterior end of the lingual body. In conclusion, morphological characteristics of the lingual papillae and their distribution in the least weasel were similar to those of the Japanese marten and ferret. The conical papillae in the lingual apex of the Japanese marten and ferret were not observed, but the conical papillae were seen in the lingual apex of the least weasel.

We examined the dorsal lingual surface of an adult Asian short-clawed otter (Aonyx cinerea) by using scanning electron microscopy. The filiform papilla on the lingual apex had some pointed processes. The connective tissue core of the filiform papillae consisted of several rod-like processes, and the connective tissue core with a long process was rarely observed. The filiform papilla on the lingual body had several pointed processes and the fungiform papilla had smooth surface. The connective tissue core of the filiform papillae consisted of a large main and several small processes. The vallate papillae were surrounded by a groove and some pads, and many processes were observed on this surface. The tongue of the Asian short-clawed otter was different from that of the Japanese marten belong to family Mustelidae.

We examined the dorsal lingual surface of an adult eastern grey kangaroo (Macropus gigantues) by scanning electron microscopy. The filiform papillae on the lingual apex and anterior body consisted of a main papilla and secondary papillae. The connective tissue core of the filiform papillae on the lingual apex had several processes. The filiform papillae on the lingual posterior body were thread-like in shape. The connective tissue core of the filiform papillae on the lingual posterior body consisted of many slender processes. The fungiform papillae were round in shape. Three vallate papillae with the apex of the triangle directed posteriorly consisted of a groove and pad. Several conical papillae derived from the posterolateral margin of the tongue where foliate papillae have been shown to be distributed in many other animal species. The surface structure of the tongue in the eastern grey kangaroo resembles that of the red kangaroo.

We examined the dorsal lingual surfaces of an adult eland (Taurotragus oryx) by scanning electron microscopy. Filiform, fungiform and vallate papillae were observed. The filiform papillae of the lingual apex consisted of a larger main papilla and smaller secondary papillae. The connective tissue core of the filiform papilla was U-shaped. The fungiform papillae were round in shape. The connective tissue core of the fungiform papilla was flower-bud shaped. The filiform papillae of the lingual body consisted of a main papilla and were big as compared to that of the lingual apex. The connective tissue core of the filiform papilla resembled that of the lingual apes. The lenticular papillae of large size were limited on the lingual prominence. The connective tissue core of the lenticular papilla consisted of numerous small spines. The vallate papillae were located on both sides of the posterolateral aspects. The vallate papillae were flattened-oval shaped and the papillae were surrounded by a semicircular trench. The connective tissue core of the vallate papilla was covered with numerous small spines. The lingual surface of the eland closely resembled that of the family Bovidae.

We examined the dorsal lingual surface of an adult brush-tailed rat kangaroo (Bettongia penicillata) by scanning electron microscopy. The filiform and fungiform papillae on the lingual apex and body consisted of a main papilla and secondary papillae. The connective tissue core of the filiform papillae on the lingual apex was cylindrical in shape with a crushed top. The connective tissue core of the filiform papillae on the lingual body had one large and several small processes. The fungiform papillae were round in shape. The connective tissue core of the fungiform papillae had several depressions on its top. The surface of the vallate papillae was rough and the papillae were surrounded by a groove and a pad. Several long conical papillae derived from the posterolateral margin of the tongue where foliate papillae have been shown to be distributed in many other animal species. The long conical papillae were very similar to those of the koala and opossum.

The mammalian tongue has different functions for feeding. We investigated the morphological characteristics of the surface of the tongue of Egyptian buffalo (Bubalus bubalis) using scanning electron microscopy. The lingual surface exhibited different degrees of specialization. The tongue can be divided into the apex, body, and root. The lingual prominence was observed on the posterior area of the lingual body. The lenticular, conical, and vallate papillae were observed on the caudal part of the tongue. The filiform papillae were lingual papillae covering the entire dorsal and ventral surface of the tongue at the lingual apex; they consisted of a main process that functions to transport food materials towards the pharynx. The fungiform papillae were dispersed between the filiform papillae. Large lenticular papillae were found at the lingual prominence. The highly keratinized lenticular papillae aid the physical mastication of plant materials. Twelve vallate papillae were arranged in V shape on the lingual root. These anatomical characteristics of the lingual surface of Egyptian buffalo may enhance understanding of its feeding behavior adaptations.

We examined the dorsal lingual surface of an adult fishing cat (Prionailurus viverrinus) by scanning electron microscopy. The filiform papillae on the lingual apex had several pointed processes. The connective tissue core of the filiform papillae resembleda a well in shape. The filiform papillae on the anterior part of the lingual body were large and cylindrical in shape. The connective tissue core of the filiform papillae consisted of a large conical papilla. The filiform papillae on the central part of the lingual body were large and conical. The connective tissue core of the filiform papillae consisted of a large main process and some secondary processes. The connective tissue core of the fungiform papillae did not have processes. The vallate papillae were surrounded by a groove and a pad. The top of the connective tissue core of the vallate papillae had a rough surface with no spines.

We examined the dorsal lingual surface of an adult black-backed jackal (Canis mesomelas) by using scanning electron microscopy. The filiform papilla on the lingual apex exhibited a crown-like shape with several pointed processes. The connective tissue core of the filiform papilla was U-shaped. The filiform papillae on the lingual body had several pointed processes. The connective tissue core of the filiform papillae consisted of one large and several small conical papillae. The fungiform papillae on the lingual apex and body had a smooth surface. The connective tissue core of the fungiform papillae was not hollow and did not have processes. The vallate papillae were surrounded by a groove and pad with many processes on the surface. The connective tissue core of the vallate papillae had many ditches. Thus, the tongue of the black-backed jackal more closely resembles that of the bush dog than those of the raccoon dog or fox.

The parathyroid glands hold a special place in human anatomy, since they were the last major organ to be recognized by humans.The glands are recognized in all vertebrate animals higher than fish, and are derived from the pharyngeal pouches.The molecular signaling pathways that are involved in determining the differentiation of the glands are being elucidated.Studies in mice have demonstrated that the transcription factor encoded by Glial cells missing 2 (Gcm2) is a key regulator of parathyroid development.Recent studies indicate that the tetrapod parathyroid glands and the gills of fish are evolutionarily related structures, and that the parathyroid glands likely come into being as a result of the transformation of the gills during tetrapod evolution.The parathyroid chief cells play a central role in calcium homeostasis by sensing changes in extracellular calcium and releasing parathyroid hormone (PTH) to correct or maintain normal blood calcium levels.Chief cells undergo morphologic changes corresponding to different stages of the secretory cycle.Parathyroid oxyphil cells derived from chief cells as aging or some metabolic derangements, have the potential to produce PTH, PTH-related protein, and calcitriol.The existence of water-clear cells is confirmed in some kinds of animals, which may represent hyperfunction of the parathyroid gland.The presence of water-clear cell is associated with parathyroid hyperplasia or parathyroid adenoma.The molecular regulation of PTH synthesis and release indicates that parathyroid cells detect changes of the extracellular calcium levels by calcium-sensing receptor, which plays a central role in regulating PTH secretion.

We examined the dorsal lingual surfaces of an adult jaguar (Panthera onca) by scanning electron microscopy. The tongue of the jaguar was about 17 cm long, and the center of the lingual apex became hollow. There were 7 vallate papillae in total. The filiform papilla on the lingual apex consisted of a larger main papilla and some secondary papillae. The connective tissue core of the filiform papilla was mountain-like in shape. The connective tissue core of the fungiform papilla was mushroom-like in shape. The filiform papilla on the anterior part of the lingual body was large and cylinder-like in shape. The connective tissue core of the filiform papilla consisted of a big conical papilla and many rod-like papillae. The filiform papilla on the central part of the lingual body was a big conical papilla. The connective tissue core of the filiform papilla consisted of a rod process and bowl-like structure. The vallate papillae were located on both sides of the posterolateral aspects. The vallate papillae were flattened-oval in shape and the papillae were surrounded by a groove and pad. The top of the connective tissue core of the vallate papilla had a rough surface with no spines.

The parathyroid glands hold a special place in human anatomy, since they were the last major organ to be recognized by humans. The glands are recognized in all vertebrate animals higher than fish, and are derived from the pharyngeal pouches. The molecular signaling pathways that are involved in determining the differentiation of the glands are being elucidated. Studies in mice have demonstrated that the transcription factor encoded by Glial cells missing 2 (Gcm2) is a key regulator of parathyroid development. Recent studies indicate that the tetrapod parathyroid glands and the gills of fish are evolutionarily related structures, and that the parathyroid glands likely come into being as a result of the transformation of the gills during tetrapod evolution. The parathyroid chief cells play a central role in calcium homeostasis by sensing changes in extracellular calcium and releasing parathyroid hormone (PTH) to correct or maintain normal blood calcium levels. Chief cells undergo morphologic changes corresponding to different stages of the secretory cycle. Parathyroid oxyphil cells derived from chief cells as aging or some metabolic derangements, have the potential to produce PTH, PTH-related protein, and calcitriol. The existence of water-clear cells is confirmed in some kinds of animals, which may represent hyperfunction of the parathyroid gland. The presence of water-clear cell is associated with parathyroid hyperplasia or parathyroid adenoma. The molecular regulation of PTH synthesis and release indicates that parathyroid cells detect changes of the extracellular calcium levels by calcium-sensing receptor, which plays a central role in regulating PTH secretion.

The dorsal lingual surface of scarlet macaw (Ara macao) was examined by scanning electron microscopy. Macroscopically, the lingual apex of the scarlet macaw had a lip-like shape. Three parts were distinguished in the dorsal surface of the tongue: the apex, body, and root of the tongue. The surface of the lingual apex had many grooves toward lingual root. The surface of the lingual apex was relatively smooth. The central surface of the papillary layer in the lingual apex after removal of the epithelium consisted of numerous dermal papillae, but the papillae were not observed in the lateral region. A pair of openings of the lingual glands was observed in the posterolateral region of the lingual body. The opening of the lingual gland after removal of the epithelium showed more clear structure than before removal. Many conical papillae in the posterior region of the lingual body were observed. The structure of the tongue of the scarlet macaw was different from that of the rainbow lorikeet.

The dorsal lingual surface of the Egyptian rousette bat was examined by scanning electron microscopy. Filiform, fungiform and vallate papillae were observed. The filiform papillae were distributed over the entire dorsal surface of the tongue. The filiform papillae notably differed in morphology by their location on the tongue and could be classified into 5 types: 1) scalelike, 2) small crown-like, 3) giant trifid, 4) large crown-like, 5) conical papillae. The fungiform papillae were present rounded bodies on the anterior 2/3 of the tongue. The Egyptian rousette bat showed the a triangular arrangement of the three vallate papillae, with the apex of the triangle directed posteriorly. These findings indicate that the tongue of the Egyptian rousette bat is similar to that of the large flying fox.