Oral Structures

Question 1

Function of Human Oral Cavity

Answer 1

• Gateway to digestive system
• Articulation and resonation of sound
• modulation of the tongue helps us talk
• respiration
• defense - teeth

Question 2

Spaces of Oral Cavity

Answer 2

• Vestibule - space between lips and gums
• oral cavity proper
• Pharynxx - back part of oral cavity

Question 3

Oral Mucous membrane

Answer 3

• stratified squamous epithelium
• places with keratinized (a lot of friction) and non keratinized
• wet almost all of the time
• sublingual area is permeable to certain substances

Question 4

External Surface of lips and cheeks

Answer 4

• tough
• keratinized stratified squamous
• hair and sweat glands

Question 5

Vermilion Zone

Answer 5

• Red area of lips
• transition between keratinized and non keratinized
• high proportion of capillaries
• no hair or sweat glands

Question 6

internal surface of lips and cheeks

Answer 6

• oral mucosa
• non keratinized
• tethered to underlying muscle at intervals resulting in many folds

Question 7

Two main regions of the tooth

Answer 7

Crown
- white part of the tooth
- formed (covered) by enamel
Root
- inside the gums
Neck
- between the crown and root

Question 8

Enamel

Answer 8

• Made from calcium crystals

- strongest component in the human body

Question 9

Dentin

Answer 9

• forms majority of the tooth
• under the enamel
• contains collagen and mineral
• harder than bone but not enamel

Question 10

Pulp

Answer 10

• within dentin
• connective tissue
• contains capillaries and nerves
• where you feel a tooth ache
• Apical foramen - communication between the pulp and bottom of tooth (root canal)
• Under the odontoblasts
• as more dentin is laid down, the pulp cavity diminishes in size

Question 11

Cementum

Answer 11

• bone layer of tooth root
• attaches tooth to periodontal ligament
• separates dentin from periodontal ligament
• produced by cementocytes
• Rich in calcium
• Contains Sharpey’s Fibers

Question 12

Periodontal ligament

Answer 12

• Flexible
• shock absorber
• allows for wiggle movement
• anchors tooth in bony socket of the jaw
• continuous with gingiva (gums)

Question 13

Ameloblasts

Answer 13

• produce enamel rods

Question 14

Odontoblasts

Answer 14

• produce predentin
• predintin matures to dentin
• contain odontoblast processes which entend into small canals (dentinal tubules)

Question 15

Alveolar Processes

Answer 15

• Alveolar bone of maxillary/mandible bones

- Form sockets for dental roots

Question 16

Gingiva

Answer 16

• Attached to bone on one side and teeth on the other
• Gingival Sulcus- has a depth that is associated with healthy teeth
• the gingival sulcus is lined by non keratinized epithelium

Question 17

Development of Teeth

Answer 17

• Crown forms before the root
• root forms when crown is mostly completed and we have tooth eruption
• Bud Stage - invagination that forms a bud
• Cap stage - bud continues to form and creates a cap that deepens, also a second bud forms (origin of permanent tooth)
• Bell stage - bell structure is formed and pushes through forming the tooth (baby tooth)

Question 18

Enamel organ

Answer 18

• ectodermal origin

- cellular down growth of oral epithelium which forms enamel related structures

Question 19

Dental lamina

Answer 19

• serves as the origin for the permanent tooth

Question 20

Dental papilla

Answer 20

• Mesodermal origin
• forms the pulp
• forms dentin related structures

Question 21

Mesenchyme

Answer 21

• dental sac

- forms cementoblasts and periodontal ligament

Question 22

Palate

Answer 22

Hard Palate
- front part (2/3 of the palate)
- Bone
Soft Palate
- in the back of the mouth
- contains the uvula
- large number of taste buds
Both contain some salivary glands that produce mucous
- salivary glands in the lip as well

Question 23

The tongue

Answer 23

• allows to talk, masticate, suckle, swallow and taste
• Papillae - involved in taste
• Primarily striated muscle

Oral Portion 
- most of the papillae involved in tasting
- smooth on the bottom
- top is more rough
Pharyngeal Portion
- where the tonsils are 
Terminal Sulcus
- separates the oral and pharyngeal portions

Question 24

Filiform Papillae

Answer 24

• Most abundant
• Keratinized
• do not have taste buds

Question 25

Fungiform Papillae

Answer 25

- look like mushrooms | - contain a few taste buds

Question 26

Circumvallate Papillae

Answer 26

- Majority of the taste buds - just in front of sulcus terminalis - also called Vallate Papillae

Question 27

Taste Buds

Answer 27

- connected with sensory innervation - produce different sensations - innervated by nerves Gustatory Cells - contain microvilli - Taste detection Supportive Cells Basal Stem cells - needed for the high turnover of injured cells Taste Pore - where microvilli are located

Question 28

Lingual Tonsils

Answer 28

- located in the pharyngeal portion of the tongue - lymphoid nodules - Have epithelial glands - minor salivary glands that produce mucous

Question 29

Saliva

Answer 29

- Main composition is water - Contains proteins - in the mucin group - Enzymes - involved in digestion - Electrolytes for tissue environment - Antimicrobial factors

Question 30

Major Salivary Glands

Answer 30

- Produce Saliva - Parotid, submandibular, sublingual - encapsulated

Question 31

Minor Salivary glands

Answer 31

- All over - not encapsulated - short ducts - secrete mucous on the lip, back of the tongue and other locations

Question 32

Cell types of Major Salivary Glands

Answer 32

Serous cells - contain secretory granules Mucous Cells - secrete mucin Myoepithelial Cells - Have properties of epithelial cells and muscle cells which surround the duct and secretory portions - Facilitate the movement of saliva Plasma cells - secrete IgA - antimicrobial component

Question 33

Salivary Secretory Control

Answer 33

- Opposite effects - Parasympathetic stimulation produces less saliva - Sympathetic stimulation produces more saliva - Superior Salivary Nucleus - controls sublingual glands and submandibular glands - Inferior Salviary nucleus - innervates the parotid glands

Question 34

Salivary Secretion

Answer 34

- Primary secretion by acini | - Striated ducts contribute to electrolyte addition to saliva

Question 35

Parotid Glands

Answer 35

- Produce 25 % of saliva - Back of the mouth - innervated by facial nerve - Serous type - many granules - Largest salivary duct - Secretes water, electrolytes and amylase - Has plasma cells - produce IgA - Opens to outside on inner surface of cheek - Stenson's Duct - Abundant interstitial fat

Question 36

Submandibular Glands

Answer 36

- Produce 70% of saliva - Mixed type - majority serous with some mucous - Has serous demilunes - Primarily tubuloalveolar - Open on the floor of the mouth - Wharton's duct - Little or no interstitial fat

Question 37

Sublingual Glands

Answer 37

- produce 5% of saliva - smallest - predominately mucus - Occasional demilunes - Multiple ducts that open posteriorly to the submandibular ducts - Bartholin's Duct - No interstitial fat

Question 38

Oropharynx

Answer 38

- Conducts food from oral cavity to esophagus | - stratified squamous epithelium (non-keratinized)

Question 39

Nasopharynx

Answer 39

- Conducts air from the nasal cavities to the larynx and trachea - Pseudostratified ciliated columnar epithelium (respiratory epithelium)