Lecture 12 - Oral Flashcards
Oral mucous membrane
mostly stratified squamous epithelium (non-keratinized but friction areas are keratinized), wet mucosa, and highly permeable on the floor
Areas of high friction in mouth
gingiva, hard palate, and dorsal suface of tongue may be keratinized.
Vermillion zone
transition between keratinized and non-keratinized. Abundant dermal capillaries (red color)
Type of muscle in the lip
striated muscle.
number of permanent teeth and the division and roots
32. 8 incisors (cutting, 1 root) 4 canine (grasping, 1 root) 8 premolars (grinding, 2 roots) 12 molars (grinding, 2 roots)
number of baby teeth
20 deciduous teeth
Structure of tooth
crown (exposed) and root (in socket)
Enamel
99% calcium crystals. outer most part. Produced by ameloblasts
Dentin
bulk of the tooth. contains type I collagen and minerals
Pulp cavity
vessels and nerves. inner most part of tooth.
Apical foramen
communication area between pulp and what goes into the bone
Periodontal ligament
between cementum and the bone and allows for slight movement of teeth. continuous with gingiva
Cementum
bone layer of tooth root. Connects dentin to the ligament. produced by cementocytes
Odontoblasts
give rise to dentin (predentin first but matures). which surround the pulp cavity. processes that extend into canals (dentinal tubules)
Ameloblasts
produce enamel. Rods like structure
Branching occurs in what portion of the odontoblasts?
middle portion
Cementocytes
produce cementum
sharpey’s fibers
collagen bundles from periodontal ligament
alveolar processes
bone that forms sockets for dental roots
Gingival sulcus
space between the free gingival and crown. lined by non-keratinized epithelium.
Development of teeth
begins at 6-7 weeks of gestation. crown formation begins before root. Root will coincide with eruption
Enamel organ origin (bud phase)
ectoderm. cellular down-growth of oral epithelium. origin of crown.
Dental papilla origin (cap phase)
mesoderm. forms dentin related structures and pulp.
Mesenchyme origin (bell phase)
dental sac. forms cementoblasts and periodontal ligament.
Hard palate
first 2/3 of palate which separates nasal cavity from oral cavity. salivary glands (mucus)
Soft palate
separates nasopharynx and oropharynx. uvula. Taste buds.
Tongue
interlacing skeletal muscle. dorsal surface has thick keratinized.
oral protion of tongue
anterior 2/3 has lingual papillae.
Pharyngeal portion of tongue
posterior 1/3. lingual tonsils.
Sulcus terminalis
V-shaped shallow groove separating palatine and pharyngeal portions
3 types of papillae
filiform, fungiform, and circumvallate
Filiform papillae
most numerous, conical shaped, keratinized, no taste buds.
Fungiform papillae
mushroom shaped, contain a few taste buds
Circumvallate papillae
moat. located in front of the sulcus terminalis. Contains taste buds and glands of von ebner
Glands of von ebner
in circumvallate. deliver serous secretions to help clean.
Taste buds
gustatory cells (taste) lined by microvilli (light stainint), other cells are support cells (dark staining) and basal stem cells (connect to the nerve).
Taste pore
microvilli project into the ppore and are exposed to the microenvironment.
Lingual tonsils
minor salivary glands secrete mucus into crypts
Composition of saliva
95% water, proteins (enzymes, mucus, IgA, lysozyme, lactoferrin) and electrolytes
Location of major salivary glands
parotid, submandibular, and sublingual. All encapsulated
Minor salivary glands
not encapsulated, short ducts, and located everywhere and continuous.
Serous
more aqueous (zymogen ganules and amylase), stain dark. SAD
Mucus
mucin (lubrication), more dense. stain light.
Acini of glands
formed by myoepithelial cells. similar to muscle to help secret saliva.
type of ducts for salivary glands
striated ducts which help modify with electrolytes
Parasympathetic stimulation of saliva
more saliva
Sympathetic stimulation of saliva
reduces saliva.
2 nuclei in the brain stem that affect saliva
superior - sublingual and submandibular
inferior - parotid
Parotid glands
25% of saliva. serous type (compound alveolar) - water, electrolytes, and amylase, IgA. Stenson’s duct - inner cheek.
Submandibular glands
70% of saliva. mixed type (serous predominates) with serous demilunes (compound tubuloalveolar) - mucin. Wharton’s duct on the floor of the mouth.
Sublingual glands
5% saliva. smallest. mixed type (mucous predominates) with serous demilunes (compound tubuloalveolar) - mucin. Bartholin’s duct - to submandibular ducts
Oropharynx
conducts food to esophagus. stratified squamous epithelium (non-keratinized)
Nasopharynx
conducts air to the larynx and trachae. Pseudostratified ciliated columnar epithelium (respiratory)