Flashcards in Lecture 2 - Histology 1 (Baekey) Deck (108)
what are the 3 different layers of lips within the oral cavity?
what cell type is found within the mucosa of the lips?
stratified squamous epithelium (keratinized in herbivores not carnivores)
what type of tissue do you find within the core layer of the lips?
fibroelastic connective tissue and skeletal muscle
what does the primary palate form from?
caudal growth of the medial palatal process
what does the secondary palate form from?
lateral palatal processes that elevate and grow medially and use in the center with the primary palate and nasal septum
in what species do you most commonly see a cleft palate? what is it caused by?
brachycephalic dogs, Abyssinian cats
can be caused by ingestion of lupine (wildflowers) by pregnant sheep or cattle
what layers do you see within the hard palate
1. mucosa - keratinized stratified squamous epithelium
2. lamina propria - extensive vascular beds for heat exchange
what is the function of the soft palate?
divides oropharynx and nasopharynx
what is on the dorsal and ventral surface of the soft palate?
dorsal surface: nasopharynx w/ respiratory epithelium
ventral (oral) surface: keratinized stratified squamous epithelium
what are the layers of the soft palate?
1. lamina propria
2. core: fibrous connective tissue and skeletal muscle
what cell types do you find in the tongue?
stratified squamous epithelium covering a core of skeletal muscle
what are the 5 different tyeps of papillae?
5. vallate (circumvallate)
what characteristics about filiform papillae are significant?
its keratinized (especially in cats) and in rows
what characteristics about conical papillae are significant?
keratinized; located on dorsal surface of root
what characteristics about fungiform papillae are significant?
gustatory (taste buds), scattered
what characteristics about foliate papillae are significant?
taste buds, serous glands at base
what characteristics about vallate (circumvallate) papillae are significant?
ringed by furrow; taste buds; serous glands at base
what cell types do you find in taste buds?
location of tastes
sweet = tip of tongue
salt = tip
sour (acid) = sides
bitter = region of circumvallate papillae
taste is mediated by what cranial nerves?
7, 9, and 10
describe the development of teeth
1. invagination of oral ectoderm forms dental lamina
2. dental buds form at base of dental lamina
3. dental buds differentiate into inverted cups called enamel organs, which produce deciduous teeth
what is dental papilla derived from?
and what does it form?
dental papilla is derived from neural crest
forms from tooth dentin and pulp
occurs in each deciduous tooth as downward growth of root exerts pressure against alveolar bone, and the crown is forced upward to break through enamel organ and gingiva
describe the development of permanent teeth
a second bud forms off of the dental lamina. the growing permanent tooth puts pressure on the root of the deciduous tooth, causing the root to be resorbed and the deciduous tooth to fall out
what is an example of ectopic teeth?
ear teeth in horses
what are the 3 cell types seen in teeth
apical processes (Tome's processes) secrete slightly mineralized rods; mineralization initiates in rods, forming enamel (the hardest substance in the body)
neural crest origin
- deposit predentin at the dentinoenamel junction
- predentin is mineralized, forming dentin
- odontoblastic processes extend as odontoblasts retreat
forms cementum which binds dentin to alveolar bone via peridontal ligaments