Q: What is the prominent line that runs from the uvula to the incisive papilla?
(A). Palatine raphe
(B). Palatine rugae
(C). Labial frenum
(D). Circumvallate papillae
- Palatine raphe is the prominent seam line that runs from the uvula to the incisive papilla on the surface of the palate.
- Palatine rugae are the firm irregular ridges of wavelike tissue on the surface of the palate and are perpendicular to the palatine raphe.
- Labial frenum is the vertical band that attaches the lips to the alveolar mucosa.
- Circumvallate papillae are larger papillae on the base of the tongue that contain taste buds.
Answer: (A). Palatine raphe
Landmarks of the oral cavity are located in StudentRDH’s Head and Neck anatomy chapter for the national dental hygiene boards. If you are a full package member, please jump ahead and keep studying or review this information. You can also read about the landmarks of the tongue and neck. This will complete your knowledge. If you are studying for another exam, this is still useful.
Learn more for the dental hygiene boards
If you feel productive today, here are a few more landmarks to know related to the tongue.
o Base of the tongue: posterior one-third of the tongue.
o Body of the tongue: anterior two-thirds of the tongue.
o Dorsal surface of the tongue: the top surface of the tongue.
o Filiform papillae: most numerous papillae on the dorsal surface.
o Fungiform papillae: mushroom-shaped papillae, appear as red dots.
o Sulcus terminalis: V-shaped groove separating the body and base of the tongue.
o Lingual papillae: larger papillae at the base of the tongue.
o Lingual tonsil: an irregular mass of lymphoid tissue in the far back of the tongue (posterior to circumvallate papillae).
o Circumvallate papillae: larger papillae lined along the sulcus terminalis (10-14 in number).
o Foramen cecum: depression located in the midline of the tongue in the V-shaped groove.
o Lateral surface of the tongue: sides of the tongue.
o Foliate papillae: papillae on the sides of the tongue.
o Ventral surface of the tongue: the bottom surface of the tongue.
o Lingual veins: dark veins on the ventral surface that are more visible on elderly patients.
o Plica fimbriata: bilateral fold next to the lingual veins.
o Lingual frenum: a band of tissue between the ventral side of the tongue and floor of the mouth.
o Sublingual caruncle: duct opening for the submandibular and sublingual salivary glands.
o Lingual tonsil is an irregular mass of lymphoid tissue in the far back of the tongue (posterior to the circumvallate papillae). Sulcus terminalis is a V-shaped groove separating the body and base of the tongue.
If StudentRDH has to choose the TOP important fact for the dental hygiene boards of the NBDHE/NDHCE, they would be the filiform papillae. The reason why I want to highlight these specific papillae is because when the tongue is affected by median rhomboid glossitis or geographic tongue, it is those filiform papillae that are affected. That is why the erythema (red) area is smooth – the filiform papillae are NOT there anymore! But, these papillae do NOT play in role in taste. Only the fungiform papillae, foliate papillae, and the circumvallate papillae contain taste buds.
Learn more about how the taste buds work
Now we know the two papillae of the tongue that can help you detect taste, let’s be more curious! Honestly, this is all related to the National or regional dental hygiene board exams (CSCE, CDCA, CRDTS, WREB, NBDHE, NDHCE), but it is always fun to know more. This is directly from PubMed Health, U.S. National Library of Medicine.
Fungiform papillae
Fungiform papillae are the most common: between 200 and 400 bumps are spread all over the surface of the tongue. They are found mostly at the tip of the tongue and at the edges where they make sure that these areas are especially sensitive to taste. Fungiform papillae not only detect taste, they also contain sensory cells for touch and temperature. Each papilla contains 3 to 5 taste buds.
Circumvallate papillae
Circumvallate papillae are very large and found at the base of the tongue, where the throat begins. Every person has only 7 to 12 circumvallate papillae, yet these papillae each contain several thousand taste buds. Circumvallate papillae are round, raised, and visible to the naked eye. They are arranged in the shape of a V at the back of the tongue. These papillae are called circumvallate papillae, because they are surrounded by a trench containing many glands that “rinse” the taste-producing substances into the sensory cells.
Foliate papillae
Foliate papillae can also be seen with the naked eye on the rear edges of the tongue. There you can see several folds that lie close together. Our tongue has about 20 foliate papillae, each of which has several hundred taste buds.
What are taste buds?
Taste buds are the true taste organ. They have numerous sensory cells that are in turn connected to many different nerve fibers.
Each taste bud has between 10 and 50 sensory cells. These cells form a capsule that is shaped like a flower bud or an orange. At the tip of this capsule, there is a pore that works as a fluid-filled funnel. This funnel contains thin, finger-shaped sensory cell extensions, which are called taste hairs. Proteins on the surface bind chemicals to the cell for tasting.
The taste buds are located in the walls and grooves of the papillae. Adults have between 2,000 and 4,000 taste buds in total. The sensory cells in the taste buds are renewed once a week.
Most of the taste buds are on the tongue. But there are also cells that detect taste elsewhere inside the oral cavity: in the back of the throat, epiglottis, the nasal cavity, and even in the upper part of the esophagus. Infants and young children also have sensory cells on their hard palate, in the middle of their tongue as well as in the mucous membranes of their lips and cheeks.
The final step in perceiving taste is transferred to the nervous system. This is done by several cranial nerves. All information is carried along the cranial nerves to the part of the lower section of the brainstem (the medulla oblongata). At that point, there is a split: Some fibers carry taste signals together with signals from other sensory perceptions like pain, temperature or touch through several exchange points to consciousness.
The other fibers pass over these exchange points of conscious perception and lead directly to the parts of the brain that are connected with sensory perception and which are responsible for securing our survival. It is here that taste signals are combined with different smell signals.
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(Disclaimer: StudentRDH is NOT affiliated with the NBDHE, NDHCE, CSCE, CDCA, WREB.)
