Illustrated Dental Embryology Histology and Anatomy 4th ed By Margaret J. Fehrenbach -Test Bank

Illustrated Dental Embryology Histology and Anatomy 4th ed By Margaret J. Fehrenbach -Test Bank

Chapter 09: Oral Mucosa

MULTIPLE CHOICE

1. Both the attached gingiva and buccal mucosa are mainly pinkish in color and not reddish due to the:
a. vascularity of the lamina propria.
b. closeness to bone tissue.
c. decreased number of melanocytes.
d. increased thickness of the epithelial layers.

ANS: D
The nonkeratinized stratified squamous epithelium of the labial mucosa and buccal mucosa is extremely thick and overlies and obscures a lamina propria with an extensive vascular supply, giving the overall mucosa an opaque and pinkish appearance. The attached gingiva has a thick layer of mainly parakeratinized stratified squamous epithelium that obscures the extensive vascular supply in the lamina propria, making the tissue appear opaque and pinkish.

REF: Chapter 9, Labial Mucosa and Buccal Mucosa: Histologic Features, Page 110 | Chapter 9, Attached Gingiva: Histologic Features, Page 113

2. The basal layer of oral mucosa in the oral cavity generally has:
a. columnar-shaped cells.
b. two cell layers.
c. cells undergoing mitosis.
d. keratin being produced.

ANS: C
The basal layer for both nonkeratinized and keratinized stratified squamous epithelium is a single layer of cuboidal epithelial cells overlying the basement membrane, which, in turn, is situated superior to the lamina propria.

REF: Chapter 9, Nonkeratinized Stratified Squamous Epithelium, Page 107

3. In the oral cavity, masticatory mucosa always contains a(n):
a. keratin layer without nuclei.
b. distinct granular layer.
c. prickle layer.
d. underlying submucosa.

ANS: C
Histologically, masticatory mucosa is associated with orthokeratinized stratified squamous epithelium as well as parakeratinized stratified squamous epithelium. Superficial to the basal layer is the prickle layer for both types of keratinization.

REF: Chapter 9, Masticatory Mucosa, Page 105 | Chapter 9, Orthokeratinized Stratified Squamous Epithelium, Page 105 | Chapter 9, Parakeratinized Stratified Squamous Epithelium, Page 108

4. When viewing the oral mucosa of the floor of the mouth through a microscope, which of the following can be noted?
a. Thick epithelial layers
b. Narrow connective tissue papillae
c. Extensive vascular supply
d. Keratinized epithelium

ANS: C
The floor of the mouth has an extremely thin, nonkeratinized stratified squamous epithelium overlying, but not obscuring, a lamina propria with an extensive vascular supply. The connective tissue papillae of the lamina propria are broad in the floor of the mouth.

REF: Chapter 9, Ventral Tongue Surface and Floor of the Mouth: Histologic Features, Page 111

5. Which of the following areas of the oral cavity is categorized as a lining mucosa?
a. Attached gingiva
b. Hard palate
c. Dorsal tongue surface
d. Soft palate

ANS: D
Lining mucosa includes the buccal mucosa, labial mucosa, and alveolar mucosa, as well as the mucosa lining the ventral surface of the tongue, floor of the mouth, and soft palate. Histologically, lining mucosa is a type that is associated with nonkeratinized stratified squamous epithelium.

REF: Chapter 9, Lining Mucosa, Page 104

6. Which of the following statements concerning pigmentation in the oral cavity is correct?
a. Melanin is formed by epithelial basal cells.
b. Pigmentation is most noticeable in the alveolar mucosa.
c. The number of melanocytes differs according to clinical appearances.
d. Clinical levels of pigmentation are controlled by genetic programming.

ANS: D
Melanin is a pigment formed by melanocytes, which are epidermal cells derived from the neural crest cells. Because melanocytes are evenly distributed throughout the oral mucosa, clinical levels of pigmentation are based on the degree of melanin-producing activity of the melanocytes, which is controlled by genetic programming. Melanocytes are clear cells that occupy a position in the basal layer of the stratified squamous epithelium between the dividing epithelial cells. Pigmentation appears most abundant in the attached gingiva at the base of the interdental gingiva associated with both dentitions.

REF: Chapter 9, Oral Mucosal Pigmentation, Page 119

7. What type of tissue makes up the bulk of the lamina propria of the oral mucosa?
a. Connective tissue
b. Muscle tissue
c. Nerve tissue
d. Epithelium

ANS: A
The entire oral cavity has an epithelial covering with connective tissue making up the bulk of lamina propria.

REF: Chapter 9, Oral Mucosa Properties, Page 104

8. In a young adult, the buccal mucosa may contain Fordyce spots, which refer to:
a. salivary gland tissue trapped in the lamina propria.
b. deposits of sebum from misplaced sebaceous gland tissue.
c. hyperkeratinized areas from localized tissue trauma.
d. remnants of tonsillar tissue misplaced in the epithelium.

ANS: B
A variable number of Fordyce spots are scattered throughout the tissue. These are a normal variant, visible as small, yellowish bumps on the surface of the mucosa. They correspond to deposits of sebum from misplaced sebaceous glands in the submucosa.

REF: Chapter 9, Labial Mucosa and Buccal Mucosa: Clinical Appearance, Page 110

9. The attached gingiva of the oral cavity consists of which type of oral mucosa?
a. Alveolar mucosa
b. Masticatory mucosa
c. Specialized mucosa
d. Lining mucosa

ANS: B
The oral mucosa of the attached gingiva that covers the alveolar process of the dental arches is classified as a masticatory mucosa. Alveolar mucosa is a type of lining mucosa.

REF: Chapter 9, Attached Gingiva: Clinical Appearance, Page 112

10. Melanin pigment for the oral cavity is synthesized in which of the following cells?
a. Melanocytes
b. Melanosomes
c. Keratinocytes
d. Nonkeratinocytes

ANS: B
The melanocytes have small cytoplasmic granules as inclusions called melanosomes, which store the melanin pigment that they have formed. They inject these granules into the neighboring, newly formed epithelial cells of the basal layer.

REF: Chapter 9, Oral Mucosal Pigmentation, Page 119

11. The mucogingival junction is absent from which of the following oral surfaces?
a. Buccal surface of the maxillary arch
b. Palatal surface of the maxillary arch
c. Facial surface of the mandibular arch
d. Lingual surface of the mandibular arch

ANS: B
There are three areas where the anatomic feature of the mucogingival junction can be noted: on the facial of the maxillary arch and on both the facial and lingual of the mandibular arch but not on the palate.

REF: Chapter 9, Attached Gingiva: Clinical Appearance, Page 112

12. Keratohyalin granules are located in which of the following epithelial layers in the oral cavity?
a. Stratum spinosum
b. Stratum granulosum
c. Stratum corneum
d. Stratum basale

ANS: B
Superficial to the prickle layer is the granular layer, or stratum granulosum. The epithelial cells in this layer are flat and stacked in a layer three to five cells thick. In the cytoplasm, each of the cells has a nucleus with prominent keratohyaline granules, which stain as dark spots. The keratohyaline granules form a chemical precursor for the keratin (keratohyalin) that is found in the more superficial layers.

REF: Chapter 9, Orthokeratinized Stratified Squamous Epithelium, Page 108

13. Which of the following layers make up the bulk of nonkeratinized epithelium in the oral cavity?
a. Basal layer
b. Intermediate layer
c. Superficial layer
d. Prickle layer

ANS: B
The intermediate layer makes up the bulk of nonkeratinized stratified squamous epithelium. Each area of lining mucosa has at least three layers within the epithelium: basal, intermediate, and superficial. The prickle cell layer is found instead in both orthokeratinized stratified squamous epithelium as well as parakeratinized stratified squamous epithelium.

REF: Chapter 9, Nonkeratinized Stratified Squamous Epithelium, Page 108

14. Which of the following layers of nonkeratinized stratified squamous epithelium produces the basal lamina of the basement membrane within the oral mucosa?
a. Basal layer
b. Intermediate layer
c. Superficial layer
d. Prickle layer

ANS: A
The basal layer produces the basal lamina of the basement membrane. Each area of lining mucosa has at least three layers within the epithelium: basal, intermediate, and superficial. The prickle cell layer is found instead in both orthokeratinized stratified squamous epithelium as well as parakeratinized stratified squamous epithelium.

REF: Chapter 9, Nonkeratinized Stratified Squamous Epithelium, Page 107 | Chapter 9, Orthokeratinized Stratified Squamous Epithelium, Page 107

15. Which is the most superficial layer of the lamina propria of oral mucosa?
a. Dense layer
b. Capillary plexus
c. Submucosa
d. Papillary layer

ANS: D
The lamina propria, like all forms of connective tissue proper, has two layers: papillary and dense. The lamina propria, like all forms of connective tissue proper, has two layers: papillary and dense. Between the papillary layer and the deeper layers of the lamina propria is a capillary plexus. A submucosa may or may not be present deep to the dense layer of the lamina propria, depending on the region of the oral cavity.

REF: Chapter 9, Lamina Propria of Oral Mucosa, Page 108

16. What is the most common cell in the lamina propria of oral mucosa?
a. Mast cell
b. Fibroblast
c. Macrophages
d. Lymphocytes

ANS: B
The most common cell in the lamina propria of all types of oral mucosa, similar to all connective tissue proper, is the fibroblast. Other cells present in the lamina propria in smaller numbers are white blood cells, such as macrophages, lymphocytes, and mast cells.

REF: Chapter 9, Lamina Propria of Oral Mucosa, Page 109

17. Which of the following is considered correct regarding hyperkeratinization of the oral mucosa?
a. It commonly occurs on buccal mucosa with the linea alba.
b. It is associated with chronic freezing of the tissue.
c. It is a response to frictional but not chemical trauma.
d. Changes are reversible even if the source of the injury is not removed.

ANS: A
Nonkeratinized epithelium may, however, readily transform into a keratinizing type in response to frictional or chemical trauma, in which case it undergoes hyperkeratinization. Hyperkeratinization commonly occurs on the usually nonkeratinized buccal mucosa when the linea alba forms. Hyperkeratinized tissue is also associated with the chronic heat production from smoking or hot fluids on the hard palate in the form of nicotinic stomatitis. Changes such as hyperkeratinization are reversible if the source of the injury is removed, but it takes time for the tissue to shed the keratin.

REF: Chapter 9, Clinical Considerations for Oral Mucosa Pathology, Page 109

18. Which lingual papillae are found in lesser numbers on the body of the dorsal surface of the tongue?
a. Circumvallate
b. Foliate
c. Fungiform
d. Filiform

ANS: C
The fungiform lingual papillae are found in lesser numbers than are the filiform on the body of the dorsal surface of the tongue. The circumvallate lingual papillae are lined up in an inverted V-shaped row on the dorsal surface of the tongue facing the pharynx, just anterior to the sulcus terminalis. The foliate lingual papillae appear on the lateral surface of the tongue in its most posterior part. The filiform lingual papillae are the most common lingual papillae located on the body of the dorsal surface of the tongue.

REF: Chapter 9, Fungiform Lingual Papillae, Page 117-118

19. Where are the taste buds located within the circumvallate lingual papillae on the dorsal surface of the tongue?
a. None are present within the epithelium.
b. Hundreds are surrounding the entire base.
c. The are on the lateral parts of structure.
d. A variable number can be found in the most superficial part.

ANS: B
Hundreds of taste buds are located in the epithelium surrounding the entire base of each circumvallate lingual papilla, opposite the circular trough lined by the surrounding tongue surface tissue. No taste buds are present in the epithelium of the filiform lingual papillae. Taste buds are located in the epithelial layer on the lateral parts of the leaf-shaped structure of the foliate lingual papillae. A variable number of taste buds are located in the most superficial part of the epithelial layer of the fungiform lingual papillae; however, taste buds are not located near the base of the structure.

REF: Chapter 9, Circumvallate Lingual Papillae, Page 118

20. Which of the following lingual papillae are involved in the normal variation of geographic tongue?
a. Circumvallate
b. Foliate
c. Fungiform
d. Filiform

ANS: D
Geographic tongue is a type of normal variation that shows the sensitivity of the filiform lingual papillae to changes in their environment. The lesion appears as red and then paler pink to white patches on the body of the tongue; these patches change shape with time, resembling a geographic map.

REF: Chapter 9, Clinical Considerations for Tongue Pathology, Page 118

21. Which of the following lingual papillae are involved in the lesion of black hairy tongue?
a. Circumvallate
b. Foliate
c. Fungiform
d. Filiform

ANS: D
Black hairy tongue is a change in the normal shedding of epithelium of the filiform lingual papillae, so it does not occur. As a result, a thick layer of dead cells and keratin builds up on the tongue surface, which becomes extrinsically stained by tobacco, medications, or chromogenic (colored) oral bacteria. In some cases, it might be an effect of fungal overgrowth, possibly as a result of high doses of antibiotics or radiation therapy.

REF: Chapter 9, Clinical Considerations for Tongue Pathology, Page 119

22. Which of the following changes can occur in the oral mucosa as it ages?
a. Increase in rete ridges in epithelium
b. Increase in lingual papillae on the dorsal tongue surface
c. Decrease in taste buds with the lingual papillae
d. Decrease in lingual veins on the ventral surface of the tongue

ANS: C
Aging of the oral mucosa reduces the number of lingual papillae and associated taste buds. The rete ridges in the epithelium are also reduced. Also, the lingual veins enlarge to form lingual varicosities on the ventral surface of the tongue.

REF: Chapter 9, Oral Mucosa Turnover Time, Repair, and Aging, Page 121

23. Which of the following regions in the oral cavity has the lowest turnover times?
a. Hard palate
b. Floor of the mouth
c. Buccal and labial mucosa
d. Attached gingiva

ANS: A
The turnover time is the time it takes for the newly divided cells to be completely replaced throughout the tissue. The turnover time differs for each of the basic tissue types in the orofacial region, as well as for specific regions of the oral cavity. The hard palate has the lowest turnover time (in mean values) in the oral cavity at 24 days; the floor of the mouth is higher (20 days), as well as the buccal and labial mucosa (14 days) and attached gingiva (10 days).

REF: Chapter 9, Table 9-6, Page 120

24. What is one difference in the repair process of the oral mucosa as compared to that of the skin?
a. Dry scab is present.
b. Clot stays moist over time.
c. Inflammatory response is triggered.
d. Fibroblasts migrate to produce immature connective tissue.

ANS: B
The repair process of the oral mucosa is similar to that of the skin, except that it involves a moist clot and not a dried scab from clot that forms on the skin surface. After an injury to the oral mucosa, the clot from blood products forms in the area, and the inflammatory response is triggered with its white blood cells. The epithelial cells at the periphery of the injury will lose their desmosomal junctions and migrate to form a new epithelial surface layer beneath the clot. At the same time, fibroblasts migrate to produce an immature connective tissue in the injured lamina propria deep to the clot and newly forming epithelial surface.

REF: Chapter 9, Oral Mucosa Turnover Time, Repair, and Aging, Page 120

25. Which of the following statements concerning granulation tissue formation during the repair process in the oral mucosa is correct?
a. Has more fibers in the lamina propria
b. Has a decreased number of blood vessels
c. Appears as a hard, dark red dried scab
d. Is later replaced by firmer and paler scar tissue

ANS: D
At the same time, fibroblasts migrate to produce an immature connective tissue in the injured lamina propria deep to the clot and newly forming epithelial surface. This immature connective tissue is considered granulation tissue and has fewer fibers and an increased number of blood vessels. Granulation tissue appears as a soft, bright red tissue that bleeds easily. This temporary granulation tissue is later replaced by firmer and paler scar tissue in the affected area.

REF: Chapter 9, Oral Mucosa Turnover Time, Repair, and Aging, Page 120