Chapter 06: Tooth Development and Eruption
MULTIPLE CHOICE
- What happens to the specific cells from the enamel organ that will differentiate into preameloblasts?
| a. | Their length shortens. |
| b. | Their nuclei repolarize. |
| c. | Their cellular contents mineralize. |
| d. | They line up along the basement membrane. |
ANS: B
After the formation of the inner enamel epithelium in the enamel organ, these innermost cells grow even more columnar as they elongate and differentiate into preameloblasts, lining up alongside the basement membrane. During this differentiation process, the nucleus in each cell moves away from the center of the cell to the position farthest away from the basement membrane that separates the enamel organ from the dental papilla, which is considered cellular repolarization.
REF: Chapter 6, Preameloblast Formation, Page 62
- Which embryonic structure is specifically responsible for the development of the root?
| a. | Stellate reticulum |
| b. | Enamel organ |
| c. | Stratum intermedium |
| d. | Cervical loop |
ANS: D
The structure responsible for root development is the cervical loop, which is the most cervical part of the enamel organ, a bilayer rim that consists of only inner and outer enamel epithelium. Between the outer and inner enamel epithelium are the two innermost layers, the stellate reticulum and stratum intermedium. Earlier a depression results in the deepest part of each tooth bud of dental lamina, forming the cap shape of the enamel organ.
REF: Chapter 6, Root Development, Page 66
- If a tooth has two roots, how many horizontal epithelial extensions or flaps will be involved in its root formation?
ANS: B
During the formation of the enamel organ on a multirooted tooth, its cervical loop elongates, which allows the development of long, tongue-like horizontal epithelial extensions or flaps within it. Two or three such extensions can be present on multirooted teeth, depending on the similar number of roots on the mature tooth.
REF: Chapter 6, Multirooted Tooth Development, Page 68
- During root development, the Hertwig epithelial root sheath is entirely composed of:
| a. | all layers of the enamel organ. |
| b. | enamel organ and dental papilla. |
| c. | inner and outer cells of the dental papilla. |
| d. | inner and outer enamel epithelium. |
ANS: D
To form the root region, the cervical loop begins to grow deeper into the surrounding ectomesenchyme of the dental sac, elongating and moving away from the newly completed crown area to enclose more of the dental papilla, forming Hertwig epithelial root sheath. The cervical loop is the most cervical part of the enamel organ, a bilayer rim that consists of only inner and outer enamel epithelium.
REF: Chapter 6, Root Development, Page 66
- The dental lamina is an embryonic structure that develops from the:
| a. | oral epithelium. |
| b. | mesenchyme. |
| c. | neural crest cells. |
| d. | endodermal layer. |
ANS: A
During the latter part of the seventh week, the oral epithelium grows deeper into the ectomesenchyme and is induced to produce a layer, the dental lamina.
REF: Chapter 6, Initiation Stage, Page 53
- Enamel hypocalcification is a type of enamel dysplasia that involves:
| a. | an increased number of ameloblasts. |
| b. | a reduction in the quantity of enamel matrix. |
| c. | grooves and pitting on the enamel surface. |
| d. | interference in the metabolic processes of ameloblasts. |
ANS: D
Certain factors may interfere with the metabolic processes of the ameloblasts, resulting in enamel dysplasia, which is the faulty development of enamel. Enamel dysplasia may also involve enamel hypocalcification. This disturbance reduces the quality of the enamel maturation. The teeth appear more opaque, more yellow, or even browner because of an intrinsic staining of enamel.
REF: Chapter 6, Clinical Considerations with Apposition Stage and Maturation Stage Disturbances, Page 66
- Which of the following statements concerning active eruption of a permanent succedaneous tooth is correct?
| a. | The tooth erupts when the root is completed. |
| b. | The shedding of the associated primary tooth is intermittent. |
| c. | The first junctional epithelium is from the surrounding dental sac. |
| d. | The tooth actively erupts as gingival recession occurs. |
ANS: B
The process of shedding the primary tooth is intermittent. The tooth erupts before the root is completed. The process of eruption for a succedaneous permanent tooth is the same as for the primary tooth. The fused tissue that remains near the cementoenamel junction after the tooth erupts then serves as the initial junctional epithelium of the tooth. This process involves active eruption, which is the actual vertical movement of the tooth. This is not the passive eruption, which occurs with aging, when the gingival tissue recedes but no actual tooth movement takes place.
REF: Chapter 6, Permanent Tooth Eruption, Page 73
- How many buds in the dental lamina appear along each dental arch during odontogenesis of the primary dentition?
ANS: B
The second stage of odontogenesis is considered the bud stage and occurs at the beginning of the eighth week of prenatal development for the primary dentition. This stage is named for an extensive proliferation of the dental lamina into buds; at the end of the proliferation process involving the dental lamina of the primary dentition, both the future maxillary and mandibular arches will each have 10 buds.
REF: Chapter 6, Bud Stage, Page 54
- Nonsuccedaneous permanent teeth develop from buds that grow off an extension of:
| a. | each successional dental lamina. |
| b. | both paired palatal shelves. |
| c. | the posterior part of the intermaxillary segment. |
| d. | each primary second molar’s dental lamina. |
ANS: D
The permanent molars are nonsuccedaneous and have no primary predecessors. Instead, the six permanent molars per dental arch develop from a posterior extension of the dental lamina distal to the dental lamina of the primary second molar and its associated ectomesenchyme for each of the four quadrants of the oral cavity.
REF: Chapter 6, Cap Stage, Page 59
- During the cap stage of tooth development, the tooth germ consists of:
| a. | enamel organ and dental sac. |
| b. | enamel organ and dental papilla. |
| c. | enamel organ, dental sac, and dental papilla. |
| d. | dental sac and dental papilla. |
ANS: C
At the end of the cap stage, these three embryologic structures—the enamel organ, dental papilla, and dental sac—are now considered together to be the tooth germ, which is the primordium of the tooth.
REF: Chapter 6, Cap Stage, Page 58
- The outer cells of the dental papilla are induced to differentiate during tooth development into:
| a. | pulp tissue. |
| b. | preameloblasts. |
| c. | odontoblasts. |
| d. | cementoblasts. |
ANS: C
In the future, the outer cells of the dental papilla will differentiate into dentin-secreting cells, the odontoblasts, whereas the inner central cells become the primordium of the pulp.
REF: Chapter 6, Bell Stage, Page 62
- Which of the following embryonic structures becomes the dentinoenamel junction during completion of tooth development?
| a. | Inner cells of the dental papilla |
| b. | Outer cells of the dental papilla |
| c. | Outer enamel epithelium of the enamel organ |
| d. | Basement membrane between the enamel organ and dental papilla |
ANS: D
During the cap stage, a basement membrane still exists as before, but now it is between the enamel organ and the dental papilla, being the site of the future dentinoenamel junction.
REF: Chapter 6, Cap Stage, Page 58
- Which of the following structures is not part of the enamel organ?
| a. | Stellate reticulum |
| b. | Stratum intermedium |
| c. | Odontoblastic layer |
| d. | Outer epithelial cells |
ANS: C
During the bell stage, differentiation on all levels occurs to its furthest extent, and as a result, four different types of cells are now found within the enamel organ. These cell types include the outer enamel epithelium, stellate reticulum, stratum intermedium, and inner enamel epithelium.
REF: Chapter 6, Bell Stage, Page 60
- Which part of the tooth germ is the primary source for the periodontal ligament of the tooth?
| a. | Dental sac |
| b. | Hertwig epithelial root sheath |
| c. | Stratum intermedium |
| d. | Central cells of dental papilla |
ANS: A
In the future, the dental sac of the tooth germ will produce the periodontium, the supporting tissue types of the tooth: cementum, periodontal ligament, and alveolar process.
REF: Chapter 6, Cap Stage, Page 58
- Which part of the enamel organ is the main source of the junctional epithelium?
| a. | Outer enamel epithelium |
| b. | Stellate reticulum |
| c. | Stratum intermedium |
| d. | Inner enamel epithelium |
ANS: C
The external cells of the reduced enamel epithelium are mostly from the stratum intermedium cells, but they are possibly cellular remnants of the stellate reticulum and outer enamel epithelium; thus these undifferentiated epithelial cells will divide and multiply and eventually give rise to the junctional epithelium.
REF: Chapter 6, Primary Tooth Eruption and Shedding, Page 70
- The overlapping period between the primary and permanent dentition is best considered the _____ period.
| a. | deciduous |
| b. | adult |
| c. | secondary |
| d. | mixed dentition |
ANS: D
An overlapping period between the primary and permanent dentition during the preteen years is considered the mixed dentition period, when an individual has some teeth from both dentitions.
REF: Chapter 6, Tooth Development, Page 51
- Which of the following statements is correct when considering odontogenesis?
| a. | Has a clear-cut beginning and end point to the process |
| b. | Does not include the maturation of the dental tissues |
| c. | Parallels the formation of the face |
| d. | Does not have any identifiable stages |
ANS: C
Odontogenesis is a continuous process until completed, and there is no clear-cut beginning or end point between stages. After initiation of odontogenesis, the initial identifiable stages in tooth development include the bud stage, the cap stage, and the bell stage. Odontogenesis then progresses to the apposition stage with the formation of the partially mineralized dental tissue types, such as enamel, dentin, and cementum, and then finally to the maturation stage for these structures through continued mineralization. During these stages of odontogenesis, many physiologic processes occur. In many ways, these parallel the processes that occur in the formation of other embryonic structures, such as the face.
REF: Chapter 6, Tooth Development, Page 51
- The initiation stage of odontogenesis mainly involves the process of:
| a. | differentiation. |
| b. | proliferation. |
| c. | induction. |
| d. | morphogenesis. |
ANS: C
This first stage of tooth development, known as the initiation stage, involves the physiologic process of induction, which is an active interaction between the embryologic tissue types.
REF: Chapter 6, Initiation Stage, Page 53
- Where does the dental lamina begin to form first in the developing dental arches?
| a. | Near the midline |
| b. | Adjacent to the mental foramen |
| c. | Over the region of the future molars |
| d. | Adjacent to the developing temporomandibular joint |
ANS: A
During the later part of the seventh week, the oral epithelium grows deeper into the ectomesenchyme and is induced to produce a layer, the dental lamina. The dental lamina then begins to form initially in the midline for both arches and progresses posteriorly.
REF: Chapter 6, Initiation Stage, Page 53
- Which permanent teeth undergo partial anodontia the most within the developing oral cavity?
| a. | Third molars |
| b. | Mandibular second premolars |
| c. | Maxillary lateral incisors |
| d. | Maxillary first premolars |
ANS: A
However, partial anodontia is more common and most commonly occurs (listed in order of occurrence) with the permanent third molars, maxillary lateral incisors, and mandibular second premolars.
REF: Chapter 6, Clinical Considerations with Initiation Stage Disturbances, Page 54
- What is the known etiology of supernumerary teeth?
| a. | Hereditary factors |
| b. | Occlusal trauma involvement |
| c. | Infective teratogen considerations |
| d. | Disintegration of associated membranes |
ANS: A
These extra teeth may be either erupted or nonerupted and in both cases may cause dentition displacement, crowding, and delayed eruption to the adjacent teeth, as well as occlusal disruption.
REF: Chapter 6, Clinical Considerations with Initiation Stage Disturbances, Page 54
- Which of the following permanent teeth can be considered nonsuccedaneous?
| a. | Incisors |
| b. | Canines |
| c. | Premolars |
| d. | Molars |
ANS: D
The permanent molars are nonsuccedaneous and have no primary predecessors. Permanent teeth formed with primary predecessors are considered to be succedaneous and include the anterior teeth and premolars, which replace the primary anterior teeth and molars, respectively.
REF: Chapter 6, Cap Stage, Page 59
- Which of the following is the most common complication associated with dens in dente?
| a. | Macrodontic tooth size |
| b. | Abnormal arch spacing |
| c. | Lingual pit formation |
| d. | Hypercementosis of root surface |
ANS: C
The invagination produces an enamel-lined pocket extending from the lingual surface. This usually leaves the tooth with a deep lingual pit in the area where the invagination occurs, and it may appear as a “tooth within a tooth” on radiographic examination. This lingual pit may lead to pulpal exposure, pathology, and subsequent endodontic therapy; therefore, early detection is important.
REF: Chapter 6, Clinical Considerations with Cap Stage Disturbances, Page 59
- Which stage of tooth formation occurs for the primary dentition during the eleventh and twelfth week of prenatal development?
| a. | Bell stage |
| b. | Initiation stage |
| c. | Cap stage |
| d. | Bud stage |
ANS: A
The fourth stage of odontogenesis is considered the bell stage, which occurs for the primary dentition between the eleventh and twelfth week of prenatal development. Odontogenesis of the primary dentition begins between the sixth and seventh week of prenatal development, during the embryonic period; this first stage of tooth development is known as the initiation stage. The third stage of odontogenesis is considered the cap stage and occurs for the primary dentition between the ninth and tenth week of prenatal development. The second stage of odontogenesis is considered the bud stage and occurs at the beginning of the eighth week of prenatal development for the primary dentition.
REF: Chapter 6, Bell Stage, Page 60
- What term describes the movement of the nuclei within the inner enamel epithelium as the tissue forms into preameloblasts?
| a. | Dentinogenesis |
| b. | Repolarization |
| c. | Disintegration |
| d. | Maturation |
ANS: B
After the formation of the inner enamel epithelium in the enamel organ, these innermost cells grow even more columnar as they elongate and differentiate into preameloblasts, lining up alongside the basement membrane. During this differentiation process, the nucleus in each cell moves away from the center of the cell to the position farthest away from the basement membrane that separates the enamel organ from the dental papilla, which is considered cellular repolarization.
REF: Chapter 6, Preameloblast Formation, Page 62
- What is the angled part of the ameloblast that secretes the enamel matrix?
| a. | Inner enamel epithelium |
| b. | Repolarized preameloblasts |
| c. | Tomes process |
| d. | Disintegrating basement membrane |
ANS: C
The enamel matrix is directly secreted from Tomes process, an angled distal part of each ameloblast that faces the fully disintegrated basement membrane, formed from the group movement of the ameloblasts away from the basement membrane.
REF: Chapter 6, Ameloblasts, Enamel Matrix, and Dentinoenamel Junction Formation, Page 64
- Where does the initial teeth for both dentitions develop?
| a. | Anterior maxillary region |
| b. | Anterior mandibular region |
| c. | Posterior maxillary region |
| d. | Posterior mandibular region |
ANS: B
The initial teeth for both dentitions develop in the anterior mandibular region, followed later by the anterior maxillary region, and then development progresses posteriorly in both jaws.
REF: Chapter 6, Tooth Development, Page 51
- During what period of prenatal development is most of the permanent dentition formed?
| a. | Preimplantation period |
| b. | Embryonic period |
| c. | Fetal period |
| d. | Both embryonic and fetal period |
ANS: C
Most of the permanent dentition is formed during the fetal period. The primary dentition develops during both the embryonic period and fetal period of prenatal development.
REF: Chapter 6, Tooth Development, Page 51-52
- Lack of initiation within the dental lamina results in the absence of a single tooth or multiple teeth, producing:
| a. | supernumerary teeth. |
| b. | anodontia. |
| c. | dens in dente. |
| d. | germination. |
ANS: B
Lack of initiation within the dental lamina results in the absence of a single tooth (partial) or multiple teeth (complete), producing anodontia. Abnormal initiation may result in the development of one or more extra teeth, which are considered supernumerary teeth. During the cap stage, the enamel organ may abnormally invaginate by growth into the dental papilla, resulting in dens in dente. During the cap stage, germination can occur when a single tooth germ tries unsuccessfully to divide into two tooth germs.
REF: Chapter 6, Clinical Considerations with Initiation Stage Disturbances, Page 53-54
- Tubercles are a developmental disturbance that occurs during the cap stage of tooth development with both dentitions, but with the permanent dentition it can be mainly noted on the:
| a. | occlusal surface of premolars. |
| b. | occlusal surface of third molars. |
| c. | cingulum on mandibular lateral incisors. |
| d. | cingulum of mandibular canines. |
ANS: B
Teeth may also have tubercles that appear as small rounded enamel extensions forming extra cusps. They are noted mainly on the occlusal surface of permanent molars, especially the third molars, and may also be present as a lingual extension on the cingulum on permanent maxillary anterior teeth, especially lateral incisors and canines.
REF: Chapter 6, Clinical Considerations with Cap Stage Disturbances, Page 60
Chapter 07: Cells
MULTIPLE CHOICE
- Which of the following functions are performed by the Golgi complex within the cell?
| a. | Metabolizes foreign compounds |
| b. | Produces ribosomes |
| c. | Packages protein compounds |
| d. | Produces energy for the cell |
ANS: C
The Golgi complex is involved in the functions of segregation, packaging, and transport of protein compounds within the cell.
REF: Chapter 7, Golgi Complex, Page 80
- During the cell cycle, interphase involves the cells engaging in:
| a. | organelle replacement. |
| b. | substance destruction. |
| c. | chromatin removal. |
| d. | centrosome reduction. |
ANS: A
Cells between mitotic divisions and within interphase engage in growth, metabolism, organelle replacement, and substance production, including chromatin and centrosome replication.
REF: Chapter 7, Table 7-2, Page 82
- Which type of cellular junction attaches the junctional epithelium to the tooth surface?
| a. | Cemental |
| b. | Lysosomal |
| c. | Desmosomal |
| d. | Hemidesmosomal |
ANS: D
Hemidesmosomes are involved as a mechanism allowing gingival tissue to be secured to the tooth surface by the epithelial attachment. A hemidesmosome involves an attachment of a cell to an adjacent noncellular surface.
REF: Chapter 7, Intercellular Junctions, Page 83
- The smallest living unit of organization in the body is a(n):
| a. | organ. |
| b. | tissue. |
| c. | cell. |
| d. | system. |
ANS: C
The smallest living unit of organization in the body is the cell because each cell is capable of performing any necessary functions without the aid of other cells. Each cell has a cell membrane, cytoplasm, organelles, and inclusions. Thus, every cell is a world unto itself.
REF: Chapter 7, Cell Properties, Page 77
- A collection of similarly specialized cells in the body is termed a(n):
| a. | organ. |
| b. | tissue. |
| c. | cell. |
| d. | system. |
ANS: B
Cells with similar characteristics of form and function are grouped together to form a tissue. Thus, a tissue is a collection of similarly specialized cells, most often surrounded by extracellular materials. The smallest living unit of organization in the body is the cell because each cell is capable of performing any necessary functions without the aid of other cells.
REF: Chapter 7, Cell Properties, Page 77
- An independent body part formed from tissue is a(n):
| a. | organ. |
| b. | tissue. |
| c. | cell. |
| d. | system. |
ANS: A
Various tissue types are then bonded together to form an organ, a somewhat independent body part that performs a specific function or functions. Cells with similar characteristics of form and function are grouped together to form a tissue. The smallest living unit of organization in the body is the cell because each cell is capable of performing any necessary functions without the aid of other cells. Organs can function together as a system.
REF: Chapter 7, Cell Properties, Page 77
- Organs in the body are know to be able to functioning together as a(n):
| a. | organ. |
| b. | tissue. |
| c. | cell. |
| d. | system. |
ANS: D
Organs can function together as a system. Various tissue types are then bonded together to form an organ, a somewhat independent body part that performs a specific function or functions. The smallest living unit of organization in the body is the cell because each cell is capable of performing any necessary functions without the aid of other cells. Organs can function together as a system.
REF: Chapter 7, Cell Properties, Page 77
- The semifluid part contained within cell membrane boundary is considered to be:
| a. | nucleoplasm. |
| b. | cytoplasm. |
| c. | tissue fluid. |
| d. | nuclear envelope. |
ANS: B
The cytoplasm includes the semifluid part contained within the cell membrane boundary, as well as the skeletal system of support or cytoskeleton. The fluid part within the nucleus is the nucleoplasm, which contains important molecules used in the construction of ribosomes, nucleic acids, and other nuclear materials. The cells in each tissue type are surrounded by extracellular materials, which include both tissue fluid and intercellular substance. The nucleus is surrounded by the nuclear envelope, a membrane similar to the cell membrane.
REF: Chapter 7, Cell Anatomy, Page 79
- The fluid part within the nucleus of the cell is considered to be:
| a. | cytoplasm. |
| b. | nucleoplasm. |
| c. | nuclear envelope. |
| d. | tissue fluid. |
ANS: B
The fluid part within the nucleus is the nucleoplasm, which contains important molecules used in the construction of ribosomes, nucleic acids, and other nuclear materials. The cytoplasm includes the semifluid part contained within the cell membrane boundary, as well as the skeletal system of support or cytoskeleton. The nucleus is surrounded by the nuclear envelope, a membrane similar to the cell membrane. The cells in each tissue type are surrounded by extracellular materials, which include both tissue fluid and intercellular substance.
REF: Chapter 7, Nucleus, Page 79
- The specialized, metabolically active structures within the cell are generally considered to be:
| a. | nuclear pores. |
| b. | organelles. |
| c. | chromosomes. |
| d. | vacuoles. |
ANS: B
The organelles are metabolically active specialized structures within the cell. Nuclear pores may pierce the nuclear envelope. In an actively dividing cell, the chromatin condenses into microscopically visible, discrete, rodlike chromosomes. The cytoplasm contains cavities or vacuoles.
REF: Chapter 7, Organelles, Page 79
- The chromosomes have clear, constricted areas near each middle, specifically considered to be:
| a. | chromatin. |
| b. | chromatids. |
| c. | centromeres. |
| d. | cytoplasm. |
ANS: C
Each chromosome has a centromere, a clear, constricted area near the middle. The chief nucleic acid in the nucleoplasm is deoxyribonucleic acid in the form of chromatin. Chromosomes become two chromatids joined by a centromere during cell division. The cytoplasm includes the semifluid part contained within the cell membrane boundary.
REF: Chapter 7, Nucleus, Page 79
- The active transport of material from a vesicle within the cell out into the extracellular environment is termed:
| a. | endocytosis. |
| b. | phagocytosis. |
| c. | exocytosis. |
| d. | interphase. |
ANS: C
Exocytosis is an active transport of material from a vesicle within the cell out into the extracellular environment. The uptake of materials from the extracellular environment into the cell is endocytosis. Endocytosis can also take the form of phagocytosis, which is the engulfing and then digesting of solid waste and foreign material by the cell through enzymatic breakdown of the material. Interphase involves the cells engaging in growth, metabolism, organelle replacement, and substance production, including chromatin and centrosome replication between mitosis.
REF: Chapter 7, Cell Properties, Page 77
- During what phase of mitosis does the chromatin condense within the cell?
| a. | Metaphase |
| b. | Prophase |
| c. | Anaphase |
| d. | Telophase |
ANS: B
During prophase, chromatin condenses into chromosomes in cell. During metaphase, chromosomes move so that their centromeres are aligned in the equatorial plane. During anaphase, centromeres split, and each chromosome separates into two chromatids. During telophase, division into two daughter cells occurs.
REF: Chapter 7, Table 7-2, Page 82
- During what phase of mitosis do the chromosomes move so that the centromeres are aligned in the equatorial plane?
| a. | Metaphase |
| b. | Prophase |
| c. | Anaphase |
| d. | Telophase |
ANS: A
During metaphase, chromosomes move so that their centromeres are aligned in the equatorial plane. During prophase, chromatin condenses into chromosomes in a cell. During anaphase, centromeres split, and each chromosome separates into two chromatids. During telophase, division into two daughter cells occurs.
REF: Chapter 7, Table 7-2, Page 82
- When does the nuclear membrane reappear during mitosis?
| a. | Metaphase |
| b. | Prophase |
| c. | Anaphase |
| d. | Telophase |
ANS: A
During metaphase, chromosomes move so that their centromeres are aligned in the equatorial plane and then the nuclear membrane reappears. During prophase, chromatin condenses into chromosomes in cell. During anaphase, centromeres split, and each chromosome separates into two chromatids. During telophase, division into two daughter cells occurs.
REF: Chapter 7, Table 7-2, Page 82
- How many phases are within interphase when it occurs between cell division?
ANS: C
Interphase has three phases: Gap 1, or G1 (initial resting phase: cell growth and functioning), Synthesis, or S (cell DNA synthesis by duplication), and Gap 2, or G2 (second resting phase: resuming cell growth and functioning). The cell division that takes place during mitosis between interphase consists of four phases: prophase, metaphase, anaphase, and telophase.
REF: Chapter 7, Cell Division, Page 81
- How many phases are within mitosis or cell division?
ANS: D
The cell division that takes place during mitosis consists of four phases: prophase, metaphase, anaphase, and telophase. Between mitosis is interphase. Interphase has three phases: Gap 1, or G1 (initial resting phase: cell growth and functioning), Synthesis, or S (cell DNA synthesis by duplication), and Gap 2, or G2 (second resting phase: resuming cell growth and functioning).
REF: Chapter 7, Cell Division, Page 81
- Which of following are metabolically inert substances in the cell that are also considered transient?
| a. | Inclusions |
| b. | Vacuoles |
| c. | Intermediate filaments |
| d. | Lysosomes |
ANS: A
The cell contains inclusions, which are metabolically inert substances that are also considered transient over time in the cell. The cytoplasm contains cavities or vacuoles. The intermediate filaments are of various types of thicker, threadlike microscopic structures within the cell that serve as part of the cytoskeleton. The lysosomes are organelles produced by the Golgi complex and function in both intracellular and extracellular digestion by the cell.
REF: Chapter 7, Inclusions, Page 81
- Which of the following organelles in a cell can appear microscopically either smooth or rough?
| a. | Golgi complex |
| b. | Lysosomes |
| c. | Cytoskeleton |
| d. | Endoplasmic reticulum |
ANS: D
The endoplasmic reticulum can be classified as either smooth or rough, which is determined by the absence or presence of ribosomes, each giving a different microscopic appearance to the structure, as well differing in function. Once the endoplasmic reticulum has modified the new protein entering the cell, it is then transferred to the Golgi complex for subsequent segregation, packaging, and transport of protein compounds. The lysosomes are organelles produced by the Golgi complex and function in both intracellular and extracellular digestion by the cell. Within the cell there is a three-dimensional system of support using cellular scaffolding, the cytoskeleton.
REF: Chapter 7, Endoplasmic Reticulum, Page 80
- Which of the following organelles are produced by the Golgi complex and function as well in both intracellular and extracellular digestion by the cell?
| a. | Lysosomes |
| b. | Ribosomes |
| c. | Endoplasmic reticulum |
| d. | Nucleus |
ANS: A
The lysosomes are organelles produced by the Golgi complex and function in both intracellular and extracellular digestion by the cell. The ribosomes are produced in the nucleolus from rRNA and protein molecules and are assembled in the cytoplasm. Once the endoplasmic reticulum has modified the new protein entering the cell, it is then transferred to the Golgi complex for subsequent segregation, packaging, and transport of protein compounds. The nucleus stores the genetic code.
REF: Chapter 7, Lysosomes, Page 80
- Which of the following is the main hydrolytic enzyme found in lysosomes?
| a. | Intercellular substance |
| b. | Hyaluronidase |
| c. | Tissue fluid |
| d. | Lysozyme |
ANS: B
The lysosomes are organelles produced by the Golgi complex and function in both intracellular and extracellular digestion by the cell. The main hydrolytic enzyme in lysosomes is hyaluronidase. The cells in each tissue type are surrounded by extracellular materials, which include both intercellular substance and tissue fluid. Lysozyme is a gastric enzyme found in the organ of the stomach during digestion.
REF: Chapter 7, Lysosomes, Page 80
- Where is the centrosome specifically located within the cell, as it plays a significant role in forming the mitotic spindle apparatus during mitosis?
| a. | Cell membrane |
| b. | Golgi complex |
| c. | Nucleus |
| d. | Mitochondria |
ANS: C
The centrosome is always located near the nucleus, which is important because it plays a significant role in forming the mitotic spindle apparatus during mitosis or cell division.
REF: Chapter 7, Centrosome, Page 81
- Which of the following is not considered a component of the cytoskeleton within a cell?
| a. | Microfilaments |
| b. | Intermediate filaments |
| c. | Microtubules |
| d. | Vacuoles |
ANS: D
The components of the cytoskeleton include microfilaments, intermediate filaments, and microtubules. The cytoplasm contains cavities or vacuoles.
REF: Chapter 7, Cytoskeleton, Page 81
- What is the main difference between the cell membrane and nuclear envelope within the cell?
| a. | Cell membrane has nuclear pores. |
| b. | Nuclear envelope is double-layered. |
| c. | Nuclear envelope contains cytoplasm. |
| d. | Cell membrane contains nucleoplasm. |
ANS: B
The nucleus is surrounded by the nuclear envelope, a membrane similar to the cell membrane, except that it is double-layered. The nuclear pores may pierce the nuclear envelope. The fluid part within the nucleus is the nucleoplasm. The cytoplasm includes the semifluid part contained within the cell membrane boundary.
REF: Chapter 7, Nucleus, Page 79
- Which of the following involves the engulfing and then digesting of solid waste and foreign material by the cell through enzymatic breakdown of the material?
| a. | Exocytosis |
| b. | Phagocytosis |
| c. | Endoplasmic reticulum |
| d. | Intermediate filaments |
ANS: B
Phagocytosis is the engulfing and then digesting of solid waste and foreign material by the cell through enzymatic breakdown of the material. Exocytosis is an active transport of material from a vesicle within the cell out into the extracellular environment. The endoplasmic reticulum’s primary functions are modification, storage, segregation, and finally transport of proteins that the cell manufactures (on the ribosomes) for use in other sections of the cell or even outside the cell. The intermediate filaments are of various types of thicker, threadlike microscopic structures within the cell and are part of the cytoskeleton.
REF: Chapter 7, Cell Properties, Page 77
Chapter 11: Head and Neck Structures
MULTIPLE CHOICE
- In a lymph node, the B-cell lymphocytes mature within the:
| a. | hilus. |
| b. | capsule. |
| c. | lymph vessel. |
| d. | germinal center. |
ANS: D
Each lymphatic nodule has a germinal center containing many immature lymphocytes. As they mature, these lymphocytes enter either the area of the nodule surrounding the germinal center or the lymph. These mature lymphocytes are of the B-cell type and are mainly involved in the humoral immune response with immunoglobulin production by the plasma cells.
REF: Chapter 11, Lymph Nodes, Page 143
- In salivary glands, which of the following structures is composed of secretory epithelial cells?
| a. | Acinus |
| b. | Capsule |
| c. | Lobule |
| d. | Excretory duct |
ANS: A
Secretory cells are found in a group, or acinus. Connective tissue surrounds the epithelium, protecting and supporting the gland. The connective tissue of the gland is divided into the capsule, which surrounds the outer part of the entire gland, and the septa. Each septum helps divide the inner part of the gland into the larger lobes and smaller lobules. The final part of the salivary gland ductal system is the excretory duct, or secretory duct, which is located in the septum of the gland.
REF: Chapter 11, Secretory Cells and Acini, Page 134
- The connective tissue capsule surrounding the salivary gland is continuous with the connective tissue septa that run between the epithelial components, creating:
| a. | nodes and nodules. |
| b. | ducts and acinus. |
| c. | lobes and lobules. |
| d. | channels and ducts. |
ANS: C
The connective tissue of the gland is divided into the capsule, which surrounds the outer part of the entire gland, and the septa. Each septum helps divide the inner part of the gland into the larger lobes and smaller lobules.
REF: Chapter 11, Salivary Gland Histology, Page 134
- The foramen cecum of the tongue is a:
| a. | groove pointing toward the pharynx. |
| b. | median line demarcating the fusion of the tongue. |
| c. | depression at the apex of the sulcus terminalis. |
| d. | collection of diffuse tonsillar tissue. |
ANS: C
The foramen cecum, which is the opening of the thyroglossal duct, is a small, pitlike depression located where the sulcus terminalis points backward toward the oropharynx. This duct shows the origin of the thyroid and the migration pathway of the thyroid gland into the neck region.
REF: Chapter 11, Thyroid Gland Development, Page 140
- The reduction in the amount of glandular secretion noted in patients with xerostomia is called:
| a. | dysplasia. |
| b. | hyposalivation. |
| c. | cystic transformation. |
| d. | ossification. |
ANS: B
The decreased production of saliva is considered hyposalivation and can result in xerostomia, or dry mouth.
REF: Chapter 11, Clinical Considerations for Salivary Gland Pathology, Page 139
- Which of the following salivary glands are associated with the circumvallate lingual papillae and secrete only serous saliva?
| a. | von Ebner |
| b. | Sublingual |
| c. | Submandibular |
| d. | Bartholin |
ANS: A
The von Ebner salivary glands are associated with the larger circumvallate lingual papillae on the posterior part of the dorsal surface of the tongue. These glands contain only serous acini and thus secrete only a watery serous secretory product. The sublingual gland has mainly mucous but with some mucous acini with serous demilunes. The submandibular gland secretes a more viscous mixed secretory product than the parotid, but it is mainly serous because it has both serous and mucous acini with serous demilunes. The short ducts associated with the sublingual gland combine to form the sublingual duct or Bartholin duct.
REF: Chapter 11, Minor Salivary Glands, Page 137
- Which of the following paranasal sinuses may be compromised with a periapical infection in a permanent maxillary molar?
| a. | Maxillary sinus |
| b. | Frontal sinus |
| c. | Sphenoidal sinus |
| d. | Ethmoidal sinuses |
ANS: A
Because the roots of the maxillary posterior teeth are in close proximity to the maxillary sinus, maxillary sinusitis can sometimes result as infection spreads from a periapical abscess associated with one of the roots of a maxillary posterior tooth.
REF: Chapter 11, Clinical Considerations for Nasal Cavity and Paranasal Sinus Pathology, Page 146
- Which of the following salivary glands is unencapsulated?
| a. | Submandibular gland |
| b. | Parotid gland |
| c. | Sublingual gland |
| d. | Both parotid and sublingual glands |
ANS: C
The sublingual salivary gland is the only unencapsulated major salivary gland. Both the parotid and submandibular salivary glands are encapsulated major salivary glands.
REF: Chapter 11, Major Salivary Glands, Page 137
- Where is the tonsillar tissue located in the oral cavity?
| a. | Epithelium |
| b. | Lamina propria |
| c. | Basement membrane |
| d. | Submucosa |
ANS: B
Intraoral tonsillar tissue consists of nonencapsulated masses of lymphoid tissue located in the lamina propria of the oral mucosa. It is covered by stratified squamous epithelium that is continuous with the surrounding oral mucosa.
REF: Chapter 11, Intraoral Tonsillar Tissue, Page 143
- The palatine tonsils are two rounded masses of variable size located between the:
| a. | lymph nodes. |
| b. | parathyroid glands. |
| c. | faucial pillars. |
| d. | base and body of the tongue. |
ANS: C
The palatine tonsils are two rounded masses of variable size located between the anterior and posterior faucial pillars. The lingual tonsil is an indistinct layer of diffuse lymphoid tissue located on the base of the dorsal surface of the tongue, posterior to the circumvallate lingual papillae. The parathyroid glands are within the thyroid gland. Lymph nodes are found throughout the head and neck regions.
REF: Chapter 11, Intraoral Tonsillar Tissue, Page 143
- Where is the lingual tonsil located in the oral cavity?
| a. | Dorsal tongue surface |
| b. | Lateral tongue surface |
| c. | Walls of the nasopharynx |
| d. | Between the faucial pillars |
ANS: A
The lingual tonsil is an indistinct layer of diffuse lymphoid tissue located on the base of the dorsal surface of the tongue. Behind the uvula, on the superior and posterior walls of the nasopharynx, are the pharyngeal tonsils, forming an incomplete ring of tissue, Waldeyer ring. The palatine tonsils are two rounded masses of variable size located between the anterior and posterior faucial pillars. The foliate lingual papillae are located on the lateral surface of the tongue.
REF: Chapter 11, Intraoral Tonsillar Tissue, Page 143
- Which of the following statements concerning salivary glands is false?
| a. | Saliva supplies the minerals for subgingival calculus formation. |
| b. | Mucoserous acini have both a group of mucous cells surrounding the lumen and a serous demilune. |
| c. | Saliva supplies the minerals for supragingival calculus formation. |
| d. | More than one myoepithelial cell can be found on a single acinus. |
ANS: A
Saliva supplies the minerals for supragingival calculus formation; gingival crevicular fluid supplies the minerals via the blood system for subgingival calculus formation. Mucoserous acini have both a group of mucous cells surrounding the lumen and a serous demilune. More than one myoepithelial cell can be found on a single acinus.
REF: Chapter 11, Salivary Glands, Page 133-134
- Which of the following can never be palpated during an extraoral examination of a patient?
| a. | Thyroid gland |
| b. | Lymph nodes |
| c. | Parathyroid glands |
| d. | Parotid gland |
ANS: C
The parathyroid glands within the thyroid gland are not palpable during an extraoral examination of a patient. The thyroid gland and parotid salivary gland can be palpated during an extraoral examination in a healthy patient. With inflammation or other disease states, the lymph nodes in the head and neck regions can be palpated during an extraoral examination.
REF: Chapter 11, Thyroid Gland, Page 143
- Which of the following ducts are associated with the terminal part of the salivary gland?
| a. | Intercalated |
| b. | Striated |
| c. | Excretory |
| d. | Both the intercalated and striated ducts |
ANS: A
The duct associated with an acinus or terminal part of the salivary gland is the intercalated duct. The striated duct is a part of the ductal system that is connected to the intercalated ducts in the lobules of the salivary gland. The final part of the salivary gland ductal system is the excretory duct, or secretory duct, which is located in the septum of the salivary gland.
REF: Chapter 11, Ductal System, Page 136
- Which of the following ducts are located in the septum of the salivary gland?
| a. | Intercalated |
| b. | Striated |
| c. | Excretory |
| d. | Both the intercalated and striated ducts |
ANS: C
The connective tissue of the gland is divided into the capsule, which surrounds the outer part of the entire gland, and the septa. Each septum helps divide the inner part of the gland into the larger lobes and smaller lobules. The final part of the salivary gland ductal system is the excretory duct, or secretory duct, which is located in the septum of the salivary gland. The duct associated with an acinus or terminal part of the salivary gland is the intercalated duct. The striated duct is a part of the ductal system that is connected to the intercalated ducts in the lobules of the salivary gland.
REF: Chapter 11, Ductal System, Page 137
- Which of the following ducts are connected to the intercalated ducts in the lobules of the salivary gland?
| a. | Intercalated |
| b. | Striated |
| c. | Excretory |
| d. | Both the intercalated and striated ducts |
ANS: B
