Oral Cavity Histology

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Answer 7

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 16

Answer 16

Question 17

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Question 20

Answer 20

Question 21

Answer 21

Question 22

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

Xerostomia

Answer 25

= dry mouth

• impaired taste
• impaired sppech
• increased mucosal injury
• increased gum an tooth disease

Question 26

Causes of Xerostomia

Answer 26

• stress
• aging
• radiation therapy
• chemotherapy
• some medications
• Sjogren’s Syndrome

Question 27

4 Types of Lingual Papillae

Answer 27

• filiform
• fungiform
• circumvallate
• foliate

Question 28

Filiform Papillae

Answer 28

•simple keratinized projections covering most of the tongue

Question 29

Fungiform Papillae

Answer 29

• interspersed among filiform papillae
• taste buds on exposed surface

Question 30

Circumvallate Papillae

Answer 30

• are conspicuous projections that lie in a posterior pointing V formation that demarcates anterior and posterior portions of the tongue
• Each circumvallate papilla is a large projection surrounded by a moat-like sulcus. Taste buds are present in the epithelium lining both sides of the sulcus.

Question 31

Foliate Papillae

Answer 31

•are elongated taste bud-bearing ridges along the lateral aspects of the tongue

Question 32

Lingual Tonsils

Answer 32

• posterior region of tongue
• Each lingual tonsil consists of a single crypt of invaginated stratified squamous epithelium associated with about a half dozen lymphoid follicles.

Question 33

Palantine Tonsils

Answer 33

• situated close to oropharynx
• The palatine tonsils have a similar structure but are much larger, with multiple deep crypts. These can trap food particles and become infected and inflamed (tonsillitis).

Question 34

Adenoids (nasopharyngeal tonsils)

Answer 34

• posterior wall of nasal cavity, midline
• composed of lymphoid follicles aggregated around a crypt, but in this case lined by pseudostratified ciliated epithelium

Question 35

Langerhans Cells

Answer 35

•located in the stratified squamous epithelium sample antigens and present them to lymphocytes within the follicle

Question 36

M Cells

Answer 36

• located in the pseudostratified ciliated epithelium
• pick up antigens at the luminal surface and deliver them to macrophages and lymphocytes in underlying follicles

Question 37

What does saliva contain?

Answer 37

• digestive enzymes (amylase for digestion of starch);
• mucin and fluid for lubrication of food and for dissolving substances which act on taste buds;
• immunoglobulins (mainly IgA; some IgM) for immune defense;
• the antibacterial enzyme, lysozyme; • proteins which form a thin protective layer on the teeth called a pellicle

Question 38

serous cells

Answer 38

• secrete the enzymes amylase and lysozyme.
• conduct transepithelial transport of polymeric antibodies (of the five antibody types, only IgA and IgM are polymeric) from the lamina propria, where it is deposited by plasma cells, into saliva. This process is mediated by the poly-Ig receptor, a glycoprotein expressed at the basolateral surface of salivary gland serous cells (as well as other epithelial cells in the mucosa of digestive, respiratory and urogenital tracts).
• The serous cells are roughly pyramid-shaped epithelial cells with basophilic cytoplasm and secretory granules in the apical cytoplasm.

Question 39

Mucous Cells

Answer 39

•are cuboidal to columnar cells with foamy cytoplasm. They secrete mucus.

Question 40

Myoepithelial Cells

Answer 40

•help expel the contents of the acini. They are spindle or stellar shaped cells underlying epithelial cells (within the basal lamina).

Question 41

Intercalated Duct Cells

Answer 41

•are low cuboidal epithelial cells with lightly staining cytoplasm.

Question 42

Striated Duct Cells

Answer 42

• are high cuboidal to columnar epithelial cells.
• The basal cytoplasm has a “striated” appearance due to the organization of mitochondria among the extensive infoldings of the basal plasma membrane. This morphology is characteristic of cells involved in active ion transport.
• The striated duct cells modify the ion and fluid composition of saliva; they can adjust the pH and the osmolarity of saliva according to the requirements of the oral cavity.

Question 43

Excretory Duct Cells

Answer 43

• are cuboidal to columnar epithelial cells. In distal regions of the ducts, these cells form a stratified epithelium 2 cell layers thick.
• Near the opening of the glands into the oral cavity the excretory duct epithelium becomes stratified squamous.

Question 44

3 Pairs of Major Salivary Glands

Answer 44

• parotid (serous)
• submandibular (mucous)
• sublingual (mixed)
• Each of the major salivary glands has a connective tissue capsule with a hilum for passage of blood vessels, nerves and lymphatics. Innervation is both sympathetic and parasympathetic.
• The main control of salivary secretion in response to food is via parasympathetic stimulation.
• Sympathetic stimulation increases mucus secretion but decreases volume by causing vasoconstriction of capillaries in the gland.

Question 45

Minor Salivary Glands

Answer 45

• underlie oral epithelium
• These glands provide a basal salivary secretion that is important for keeping the oral cavity lubricated between meals and at night.