GI Histo I Flashcards
(33 cards)
What type of cell is responsible for forming dentin matrix?
odontoblasts
What is Tome’s dentinal fibers? and what cells form this?
Formed by odontoblasts. Tome’s dentinal fibers are cytoplasmic extensions of the odontoblasts continuing through the predentin and dentinal layers to the dentin-enamel junction
What percentage of dentin matrix is organic? and how is this compared to bone?
dentin matrix is 20% organic and is mostely collagen Type I. This is compared to bone of 35% organic
What cell type forms the enamel?
Ameloblasts form enamel which covers only the tooth crown
What is the composition of enamel?
96% inorganic salts
90% calcium phosphate in form of apatite crystals
4% organic matter and water
What causes increment lines of Retzius?
periods of rhythmic growht
What are the components of the pulp?
fibroblasts, macrophages, peripheral odontoblats, reticular fibers, nerve fibers, and blood vessels. They enter the tooth via the apical foramen.
What type of cell is cementum formed from?
cells of the dental sac differentiate into cementoblasts which deposit cementum on the dentin of the root from neck of tooth to the apex.
What are the components of the periodontal membrane?
fibroblasts, osteoblasts, cementoblasts, collagen fibers, blood vessels, and nerve fibers.
What is the function of the periodontal membrane of the tooth?
binds cementum to bony socket and limits movement. Absorbs pressures of mastication and prevents this pressure from damaging alveolar bone. The tissue is also highly metabolically active.
What structure is most effected by diabetes and scurvy?
periodontal membrane.
What is the tongue composed of?
skeletal muscle and glands makes up core of tongue and is covered by mucous membrane
What structure separates the anterior 2/3 of the tongue from the posterior 1/3 of the tongue?
sulcus terminalis
What is the name of projections on the oral portion of the tongue?
lingual papillae
What are the 4 papillae that make up the lingual papillae?
filiform papillae
fungiform papillae
foliate papillae
circumvallate papillae
What specific lingual papillae is rudimentary in humans but well developing in lower animals?
foliate papillae
What specific lingual papillae is located along the sulcus terminalis surrounded by a moat and contains taste buds on the lateral walls?
circumvallate papillae
What specific lingual papillae is the most numerous, evenly distributed in oral upper portion, conical in appearance, and lack taste buds?
filiform papillae
What specific lingual papillae are relatively few in number, interspersed singly between rows of filiform papillae, have mushroom appearance, and contain taste buds?
Fungiform papillae
What cells, derived from a single stem cell, make up the taste buds?
sustentacular cells
taste cells
What cells are involved in tooth development?
odontoblasts ameloblasts pulp cementum periodontal membrane
What are the four layers of the digestive tube?
mucosa (innermost)
submucosa
muscularis externa
outermost layer: serosa and adventitia
What are the 3 components of the digestive tube mucosa?
epithelium
lamina propria
muscularis mucosa
What layer of the digestive tube includes the Meissner’s plexus?
The submucosa of the digestive tube includes the meissner’s plexus (submucosal plexus)
