Circumvallate papillae
Encyclopedia
The circumvallate papillae (or vallate papillae) are dome-shaped structures on the human tongue that vary in number from eight to twelve.
They are situated on the dorsum of the tongue
immediately in front of the foramen cecum
and sulcus terminalis
, forming a row on either side; the two rows run backward and medially, and meet in the midline.
Each papilla consists of a projection of mucous membrane
from 1 to 2 mm. wide, attached to the bottom of a circular depression of the mucous membrane (some text referred to as moats); the margin of the depression is elevated to form a wall (vallum), and between this and the papilla is a circular sulcus termed the fossa
.
The papilla is shaped like a truncated cone, the smaller end being directed downward and attached to the tongue, the broader part or base projecting a little above the surface of the tongue and being studded with numerous small secondary papillæ and covered by stratified squamous epithelium
.
Ducts of lingual salivary glands, referred to as Von Ebner's glands
empty serous secretion into the base of the circular depression (moats). The function of the secretion is presumed to flush materials from the base of circular depression to ensure that taste buds can respond to changing stimuli rapidly. (Michael H. Ross, Histology: A text and alas 5th edition)
The circumvallate papillae get SVA innervation from cranial nerve IX, the glossopharyngeal nerve
, even though they are anterior to the sulcus terminalis. The rest of the anterior 2/3s of the tongue gets SVA innervation from the chorda tympani of cranial nerve VII, distributed with the lingual nerve of cranial nerve V.
They are situated on the dorsum of the tongue
Tongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
immediately in front of the foramen cecum
Foramen cecum (tongue)
The dorsum of the tongue is convex and marked by a median sulcus, which divides it into symmetrical halves; this sulcus ends behind, about 2.5 cm from the root of the organ, in a depression, the foramen cecum , from which a shallow groove, the sulcus terminalis, runs lateral and anterior on either...
and sulcus terminalis
Terminal sulcus (tongue)
The dorsum of the tongue is convex and marked by a median sulcus, which divides it into symmetrical halves; this sulcus ends about 2.5 cm. from the root of the organ, in a depression called the foramen cecum, from which a shallow groove, the terminal sulcus, runs laterally and forward on either...
, forming a row on either side; the two rows run backward and medially, and meet in the midline.
Each papilla consists of a projection of mucous membrane
Mucous membrane
The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...
from 1 to 2 mm. wide, attached to the bottom of a circular depression of the mucous membrane (some text referred to as moats); the margin of the depression is elevated to form a wall (vallum), and between this and the papilla is a circular sulcus termed the fossa
Fossa (anatomy)
In anatomical terminology, fossa has come to mean a depression or hollow, in general, in a bone. Other parts of the body may be involved, for example, the antecubital fossa...
.
The papilla is shaped like a truncated cone, the smaller end being directed downward and attached to the tongue, the broader part or base projecting a little above the surface of the tongue and being studded with numerous small secondary papillæ and covered by stratified squamous epithelium
Stratified squamous epithelium
A stratified squamous epithelium consists of squamous epithelial cells arranged in layers upon a basement membrane. Only one layer is in contact with the basement membrane; the other layers adhere to one another to maintain structural integrity...
.
Ducts of lingual salivary glands, referred to as Von Ebner's glands
Von Ebner's glands
Von Ebner's glands are named after Anton Gilbert Victor von Ebner, Ritter von Rosenstein, who was an Austrian histologist....
empty serous secretion into the base of the circular depression (moats). The function of the secretion is presumed to flush materials from the base of circular depression to ensure that taste buds can respond to changing stimuli rapidly. (Michael H. Ross, Histology: A text and alas 5th edition)
The circumvallate papillae get SVA innervation from cranial nerve IX, the glossopharyngeal nerve
Glossopharyngeal nerve
The glossopharyngeal nerve is the ninth of twelve pairs of cranial nerves . It exits the brainstem out from the sides of the upper medulla, just rostral to the vagus nerve...
, even though they are anterior to the sulcus terminalis. The rest of the anterior 2/3s of the tongue gets SVA innervation from the chorda tympani of cranial nerve VII, distributed with the lingual nerve of cranial nerve V.