Histology Of Oral Cavity Flashcards
- Oral cavity is lined by which of 3 epithelium?
2. What is parakeratinized mean?
- Keratinized, parakeratinized, or nonkeratinized stratified squamous
- Surface cells are keratinized, but retain their nuclei
Keratinized stratified squamous:
- Function
- What 2 places of the oral cavity have it
- Location of lamina propria in these regions?
- Resists damage from abrasion
- Masticatory mucosa of gingiva and hard palate
- Directly on periosteum of underlying bone
Nonkeratinized stratified squamous
- In lining mucosa of what 5 regions?
- Lining mucosa overlies what in these regions?
- Soft palate, cheeks, inner lips, inferior surface of tongue and floor of mouth
- Submucosa containing many minor salivary glands
Outer surface of lips contains what 3 things?
Sweat glands, hair follicles, and sebaceous glands
- Where is vermilion zone?
- Type of epithelium
- Contains
- Lacks what 2 things
- How is it kept moist?
- Between skin and oral mucosa of lips
- Lightly keratinized
- Rich microvasculature (imparts pink color)
- Salivary or sweat glands
- Saliva
Dorsal mucosa on anterior 2/3 of tongue contains? Which are?
Which type is the most numerous?
Hundreds of papillae; elevations of mucus membrane
Filiform
Filiform papillae:
- Shape
- Epithelium
- Function
- Elongated cones
- Heavily keratinized
- Provide rough surface that facilitates handling of food
Fungiform papillae:
- Location
- Shape?
- __ and __ cores of lamina propria
- Interspersed among filiform papillae
- Mushroom shaped
- Well vascularized and innervated
Foliate papillae:
1. Location
- Ridges on lateral side of tongue
Vallate (circumvallate) papillae:
- Location
- Each papilla is surrounded by a groove; significance?
- Function of these glands?
- These are the largest; located anterior to terminal sulcus
- Ducts of serous salivary glands (von Ebner glands) empty into this groove
- Wash away food particles so taste buds can receive/process new stimuli
Posterior to sulcus terminalis there is a large amount of ?
Diffuse lymphoid tissue/nodules with germinal centers which constitute the lingual tonsil
- Lingual tonsil is part of?
2. Consists of what 4 tonsils?
- Waldeyer tonsillar ring
2. Palatine, lingual, tonsil, and pharyngeal (adenoid)
Taste buds:
- Function
- Located on all papilla except?
- What other 3 places are they located
- Sample general chemical composition of ingested material
- Filiform
- Mucosa of epiglottis, soft palate, and posterior wall of pharynx
Taste buds have what 3 types of cells?
Base of taste buds are located? What happens here?
Gustatory, supportive and basal (stem) cells
On basal lamina; entered by nerve fibers that form synapses with gustatory cells
- Where is the taste pore located?
- What projects into taste pores?
- What are tastants? Where do they bind?
- Apical end of taste bud
- Microvilli from apical ends taste cells
- Molecules that generate taste; bind to receptors in plasma membrane of microvilli taste cells
- Children have how many teeth?
2. 2 incisors, 1 canine, and 2 molars are located where?
- 20
2. In each half of maxillary and mandibular dental arches
- Adults have how many teeth?
2. Which extra teeth are located in each half of maxillary and mandibular dental arches
- 32
2. This space has 3 molars instead of 2 and also contains 2 premolars
Describe each part of the tooth:
- Crown
- Root
- Neck
- Projects into oral cavity from gingiva
- Fixed in alveolus by periodontal ligament/membrane
- Between crown and root (slightly constricted part)
Most of the tooth is composed of? What is it covered by in crown and root?
Dentin; covered by enamel over crown and cement over root
Pulp cavity contains?
Root canal transmits nerves and vessels where? Thru?
LCT, blood and lymph vessels, and nerves
To and from pulp cavity thru apical foramen
Dentin:
- What about its composition makes it harder than bone
- Produced by? How?
- Dentin is 70% hydroxyapatite; bone is 50-65%
2. Odontoblasts; secrete predentin matrix that is mineralized to become dentin
Odontoblasts:
- Derived from?
- Location
- Location of its processes?
- Processes are important for
- Why do they continue predentin production into adult life?
- Neural crests
- Line tooths pulp cavity
- Extend from apical surface of odonoblasts and penetrate thickness of dentin within dentinal tubules
- Maintenance of dentin matrix
- Gradually reduce size of pulp cavity and can repair dentin if tooth is damaged
Dentin:
- Unmyelinated nerve fibers extend from where to where?
- Stimulated by?
- Pulp cavity into dentinal tubules along odontoblast processes
- Stimuli like cold, heat, and acidic pH - produce tooth sensitivity
- Why is enamel the hardest component of human body
- Enamel containing fluoride is more resistant to?
- What else contributes to enamels hardness/resistance?
- 96% hydroxyapatite
- Acidic dissolution caused by microorganisms (without fluoride, tooth is more likely to decay)
- Consists of uniform interlocking columns that extend thru entire thickness of enamel layer
- What produces enamel?
- Derived from?
- Why cant enamel be replaced
- Ameloblasts
- Ectodermal lining of embryonic oral cavity
- Ameloblasts are lost once tooth erupts (because they are located on the surface, not on the bottom)
Periodontium:
- Includes what 4 structures?
- Responsible for?
- Cementum, periodontal ligament, alveolar bone, and gingiva
- Maintaining teeth in maxillary and mandibular alveolar processes
Cementum:
- Location
- Similar to bone except?
- Produced by
- Covers dentin of root of tooth
- Avascular
- Cementoblasts
Cementoblasts:
- Secrete?
- During cementum formation, what happens to cementoblasts?
- What contains cementocytes and their processes?
- ECM that undergoes mineralization
- They are incorporated into cementum and become cementocytes
- Lacunae and canaliculi in cementum
Difference between cementocytes in lacunae vs canaliculi
In lacunae, they are irregularly distributed. In canaliculi they do not form an interconnected network like in bone
Peridontal ligament (membrane):
- Composed of
- Has bundles of __ that bind what 2 things?
- Why is it unlike typical ligaments?
- Fibrous connective tissue
- Collagen (Sharpey fibers) that bind cementum and alveolar bone
- It is highly cellular and has a rich supply of blood vessels/nerves
Salivary glands:
- Type of glands
- Empty into?
- Has what 3 types of functions
- 3 major salivary glands
- Secretes
- Exocrine
- Oral cavity
- Digestive, lubricating, and protective
- Parotid, submandibular and sublingual
- Saliva
Each major salivary gland is surrounded by? Be specific
Connective tissue capsule - parenchyma consisting of secretory units and branching duct system arranged in lobules separated by septa of connective tissue
Saliva from parotid is __; submandibular/sublingual saliva is__; salvia from minor salivary glands is mostly __
Serous (watery); seromucus; mucus
Salivary secretory units consist of what 3 cell types
Serous cells, mucus cells, and myoepithelial cells
Serous cells:
- Secrete?
- Shape/structure?
- Proteins/enzymes
2. Pyramidal with round basal nuclei and well developed rER and apical secretory granules
Mucus cells:
- Shape/structure
- Have poorly staining?
- Pyramidal with a more compressed basal nuclei
2. Apical mucin granules
Myoepithelial cells:
- Located where?
- Surrounds what 3 things?
- Have contractile processes around secretory unit/duct that are important for?
- Basal lamina
- Acini, tubules and proximal ends of duct system
- Moving secretory products into and thru ducts
- __ empty into short intercalated ducts
- Short intercalated ducts are lined by what type of cells?
- These ducts join to form _
- Secretory acini
- Cuboidal epithelial cells
- Striated duct
Striated ducts:
- Lined by what type of cells; have numerous
- Cells absorb __ and folded cell membrane provides __; this facilitates?
- Columnar epithelial cells; mitochondria
- Na ions and cell membrane provides large surface area for ion transporters; rapid ion transcytosis and makes secretions slightly hypotonic
IgA
- What cells release it/where are these cells located
- Where does it bind
- How is it internalized
- What is its function
- Plasma cells in CT surrounding secretory units and small ducts
- Receptor in basal plasma membrane
- Receptor-mediated endocytosis; carried thru cell to apical plasma membrane then released to lumen
- Provides defense against specific pathogens in oral cavity
Excretory ducts:
- Ultimately connect to?
- Epithelium of small excretory ducts?
- Epithelium gradually changes to?
- Epithelium then changes to __ as it approaches oral cavity
- Oral cavity
- Simple cuboidal
- Stratified cuboidal or pseudostratified columnar
- Stratified squamous
- Which gland exclusively has serous acini
2. What does serous acini secrete? Why?
- Parotid
2. Alpha amylase to initiate hydrolysis of carbs and proline-rich proteins with antimicrobial properties
Submandibular gland is mostly serous acini, but also has __
Secretes alpha amylase and proline rich proteins as well as __, why?
Mucus secretory units capped by serous demilunes
Lysozyme for hydrolysis of bacterial walls
What predominates in sublingual gland?
What is rarely present?
Mucus secretory units
Pure serous acini is rarely present