Oral Cavity

Question 1

Oral mucosa

Answer 1

. Stratified squamous epithelium and underlying lamina propria
. Langerhans cells, Merkel cells, and melanocytes present in epithelium

Question 2

Lining mucosa of oral cavity

Answer 2

. Nonkeratinized epithelium
. Forms inner lining of lips, cheeks, soft palate, floor of mouth, and inf surface of the tongue
. Elastic fibers inflaming propria

Question 3

Masticatory mucosa

Answer 3

Keratinized//parakeratinized epithelium
. Found in gingiva and hard palate
. Tall narrow CT papillae
. Mucoperiosteum as attachment to bone

Question 4

Specialized mucosa in oral cavity

Answer 4

. Keratinized w/ papillae and taste buds

. Found on dorsal surface of tongue

Question 5

Tooth components

Answer 5

. Crown and roots

. Formed by enamel, dentin, and cementum

Question 6

Enamel

Answer 6

. Hardest part of body (96-98% hydroxyapatite)
. Thin layer covering tooth exposed to oral environment
. Derived from epithelium
. Secreted by ameloblasts (only present during development)
. Composed of enamel rods
. Small portion of enamel is covered by gingiva

Question 7

Dentin

Answer 7

. Harder than bone (70% mineral)
. Most abundant dental issue
. Lies deep to enamel in the crown and deep to cementum in the root
. Organic component (type I collagen) secreted by odontoblasts
. Permeated by closely packed dental tubules traversing entire thickness

Question 8

Odontoblasts

Answer 8

. Cell bodies aligned along inner edge of dentin

. Form peripheral body of dental pulp

Question 9

Dentinal tubules

Answer 9

. Contain long cytoplasmic processes of odontoblasts (Tomes’ fibers)

Question 10

Cementum

Answer 10

. Covers dentin of root
. Produced continuously of the root
. Similar to bone but avascular
. Secreted by cementoblasts that mature into cementocytes

Question 11

Pulp cavity

Answer 11

. Hollow cavity divided into root canal and pulp chamber in crown
. Surrounded by dentin
. Filled by loose CT (tooth pulp)
. Pup is highly innervated and vascularized

Question 12

Periodontal ligament

Answer 12

. Runs from cementum into dental alveolus in alveolar bone
. Specialized CT btw tooth and alveolar bone (connects tooth to jaw)
. Highly cellular, well vascularized
. Rich in collagen bundles
. Fibers distribute pressures fo mastication to protect bone from direct transmission of pressure

Question 13

Alveolar bone

Answer 13

. Thin layer of compact bone that forms the wall of the alveolus
. Periodontal ligament is attached to it
. Covered by gingiva w/ mucous membrane tightly attached to underling periosteum

Question 14

Tongue

Answer 14

. Interlacing bundles of skeletal muscles covered by oral mucosa
. Dorsal surface divided by sulcus terminalis (v-shaped groove) into anterior 2/3 and posterior 1/3
. Anterior to sulcus terminalis covered by specialized mucosa w/ papillae
. Posterior to sulcus terminalis has accumulations of lymph tissues forming the lingual tonsil in lamina propria of the base of the tongue

Question 15

Papillae

Answer 15

Elevations of oral mucosa

Question 16

Filiform papillae

Answer 16

. Most numerous 
. 2-3 mm long 
. Conical shape 
. Tips keratinized
. No taste buds

Question 17

Fungiform papillae

Answer 17

. Mushroom shaped
. Visible to unaided eye 
. Most at tip of tongue 
. Not keratinized
. Some taste buds

Question 18

Circumvallate papillae

Answer 18

. Large (up tp 3 mm)
. Dome-shaped
. Surrounded by moat-like furrow
. Form 1 row of 8-12 papillae just ant. To sulcus terminalis
. Many taste buds on lat. walls w/ taste receptors
. Von Ebner ducts empty serous fluid into base of furrow to wash food material away from taste buds

Question 19

Taste buds

Answer 19

. Small intraepithelial organs w/ neuroepithelial cells as most numerous cells
. Transducers of chemical stimuli to afferent nerve endings

Question 20

Foliate papillae

Answer 20

Not well developed in humans
. Leaf-shaped
. Along lateral edges of the tongues
. Have taste buds

Question 21

Palate

Answer 21

. Forms the roof of the mouth separating oral and nasal cavities
. Contains hard and soft palate and numerous submucosal glands

Question 22

Hard palate

Answer 22

. Ant. Bony part covered by masticatory mucosa

. Adheres to periosteum

Question 23

Soft palate

Answer 23

. Mobile

. Important during swallowing

Question 24

Structure of major salivary glands

Answer 24

. Branches tubuloalveolar glands

. Capsule formed by dense CT that gives rise to CT septa that divide gland into lobules

Question 25

Serous cells in salivary gland

Answer 25

. Watery secretion w/ electrolytes and enzymes
. Pyramidal cells w/ eosinophilia cytoplasm containing basophilic granules
. Similar protein-secreting cells
. Nucleus round and located near center of cell
. Basal surface rests of basal lamina

Question 26

Mucous cells in salivary glands

Answer 26

. Thick, viscous secretion
. Pale cytoplasm
. Flattened nucleus near basal surface

Question 27

Myoepithelial (basket) cells

Answer 27

. Contractile cells w/ numerous processes

Question 28

Acini

Answer 28

. Secretory portion of gland
. Outer surface has contractile myoepithelial cells
. Myoepithelial cells and acting’s enclosed by basal lamina

Question 29

Intralobular ducts

Answer 29

. Contain Intercalated ducts and striated ducts

Question 30

Intercalated ducts

Answer 30

. Drain 2 secretory units
. W/in lobule
. Lined low cuboidal epithelium

Question 31

Striated ducts

Answer 31

. Drain 2+ intercalated ducts
. Drain single lobule
. Simple cuboidal epithelium that becomes columnar as it approaches excretory duct
. Cells have characteristics of ion-transporting cells (basal infoldings w/ abundant mitochondria)

Question 32

Excretory (interlobular and interlobar) ducts

Answer 32

. Btw lobules (drain them)
. Stratified cuboidal that becomes stratified columnar as duct diameter inc.
. Becomes stratified squamous as it opens into oral cavity

Question 33

Saliva

Answer 33

. 750-1200 mL daily production
. Moistens and cleanses oral cavity
. Contains alpha-amylase to start carb digestion
. Contains lysozyme and IgA to help control microbial flora in the oral cavity
. Production under ANS control
. Sympathetic stimulation produces small amounts of protein-rich (viscous) saliva that gives feeling of dry mouth and thirst
. Parasympathetic stimulation induces production of water-rich saliva

Question 34

Parotid gland

Answer 34

. Produces 25% of saliva
. Exclusively serous salivary gland
. Secretion rich in proteins
. High alpha-amylase activity

Question 35

Submandibular salivary gland

Answer 35

. Produces 70% of saliva
. Mixed, mostly serous salivary gland
. 80% serous and 20% mucous

Question 36

Sublingual salivary gland

Answer 36

. Mixed, mostly mucous salivary gland
. CT capsule not well defined
. 30% serous (only as serous demilunes) and 70% mucous

Question 37

Sjorgen’s syndrome

Answer 37

. Autoimmune where exocrine glands (parotid) attacked

Question 38

Dry mouth syndrome

Answer 38

. Caused by damage of salivary glands

. Common in radiation treatment of head and neck cancers