Practice exam for Oral Histology

SECTION A

MULTIPLE CHOICE QUESTIONS – circle the correct answer in this test booklet.

1. Enamel is formed by which type of cell?

A) Odontoblasts
B) Enameloblasts
C) Ameloblasts
D) Fibroblasts

2. Enamel is usually % mineralised by weight:

A) 50
B) 65
C) 70
D) 96

3. Which of the following dental tissues are derived from the same embryonic source?

A) Enamel and dentine
B) Enamel and pulp
C) Enamel, dentine and pulp
D) Dentine and pulp

4. The peritubular dentine found surrounding each tubule is:

A) not true dentine
B) less calcified than intertubular dentine
C) more calcified than intertubular dentine
D) not different from intertubular dentine

5. In a healthy, mature tooth where is the location of the cell body of an odontoblast?

A) at the dentino-enamel junction
B) in the outer wall of the pulp
C) in the centre of the dentinal tubules
D) within the pulpal core

6. Secondary dentine forms:

A) before the completion of the apical foramen
B) in response to trauma
C) at the dentino-enamel junction
D) on the outside wall of the pulp

7. Enamel rods are longest:
(i) cusps tips
(ii) at the CEJ
(iii) incisal edges
(iv) at the bottom of fissures

A) i and ii
B) i and iv
C) ii and iii
D) i and iii

8. Incremental lines within the enamel that appear to transverse the rods are known as:

A) Lines of Retzius
B) Imbrication lines of Von Ebner
C) Enamel spindles
D) Perikymata


9. Which of the following properties is NOT characteristic of enamel?

A) Dynamic tissue
B) Highly mineralised
C) Nonvital
D) Highly vascular


10. Partially calcified enamel faults, which often extend from the DEJ to the outer surface, are known as:

A) Enamel tufts
B) Gnarled enamel
C) Enamel spindles
D) Enamel lamellae

PART B Short Answer Questions

1. Describe how fluoride interacts with enamel during amelogenesis and post-eruptively
(5 marks)


2. You are placing a fissure sealant in a molar tooth. A step in the process is applying an acid etching solution to the enamel area to be sealed. Describe how the histology of enamel tissues enables the sealant to adhere to the tooth using the acid etch technique
(8 marks)



3. Describe the age changes that occur in the dental pulp? How do these changes affect the response of the dental pulp to an injury such as dental caries?
(6 marks)



4. You are examining a patient and note that due to using a hard toothbrush and a vigorous action, they have worn away some of the enamel on the buccal surfaces of their molars.
4a What symptoms may these patients be experiencing and explain why?
(3 marks)











4b What would this patient be at higher risk for on these affected surfaces? Give reasons for your answer.
(2 marks)
5. Ivor Payne has come into the surgery with a toothache in his upper left quadrant. Clinically only a small break in the enamel through an occlusal pit of 26 can be detected.




A bitewing radiograph of the area shows occlusal caries well established into dentine of the 26

5a Discuss the histological properties of enamel and dentine that explain why the caries appears radiographically.
(6 marks)













5b Why would Ivor be experiencing pain from the tooth?
(4 marks)














5c What mechanisms can the pulp initiate to protect itself from the bacterial invasion?
(3 marks)

6. The following diagram shows the developing dentine and enamel tissues during the apposition stage of tooth development.
Developing enamel
Diagram from Bath-Balogh M and Fehrenbach MJ (2006) Illustrated Dental Embryology, Histology and Anatomy, 2nd edition, Elsevier Saunders: St Louis
Developing dentine


6a Label the diagram where indicated. Then in the space below, discuss the purpose of each labelled feature (9 marks)
















6b Describe what occurs to the ameloblasts and odontoblasts after formation of their relevant dental tissues, and what implications this has for the tooth.
(4 marks)







7. The junctional epithelium (JE) is considered to be the first line of defence that protects the underlying connective tissue from onslaught from bacterial toxins. How does the JE performs this function from a histological perspective.
(5 marks)











8. During a clinic session a patient presents with clinically healthy gingival tissues.
(6 marks)

a. Describe how you would record the appearance of healthy gingival tissues on your examination sheet?










b. The presence of stippling is one indicator of gingival health. Explain what causes stippling on a histological level.














c. You notice that in one area, around the 34, there is an isolated area of 4-5 mm of recession. Outline any possible cause/s of this isolated case.












9. Explain how the periodontal ligament performs the following functions:
(7 marks)


Formative/regenerative







Nutritive








Sensory








Adaptive








Supportive








10. What radiographic indications could give you evidence of a healthy attachment apparatus? (4 marks)















11. Draw a series of clearly labelled diagrams to represent a tooth and its supporting structures. The following must be included: (pencil can be used to answer this question) (18 marks)

Enamel Alveolar crest
Dentine CEJ
Cementum Apex
Junctional epithelium Lamina dura
Sulcular epithelium Free gingiva
Gingival margin Attached gingiva
Mucogingival junction Alveolar mucosa
Free gingival groove Gingival col area

Think tank begins!

Here are some oral histology questions to start blogging.

1. Explain how gingival recession occurs and what are some of the causes of recession? Why would patients with thin gingival biotypes be more prone to gingival recession than those with thicker gingival biotypes?

 

2.     Explain the meaning of probing depth.

a.    What is considered to be a healthy probing depth?

b.    What is a periodontal pocket?

c.    Can you determine the depth of a periodontal pocket from a radiograph? Justify your answer.

3.          What is a pseudopocket? How is this formed?

4.   What is attachment loss? Why is this considered to be a more critical determinant of periodontitis than pocket depths alone?

Practice Test for 16/5 Hum Bio

None of the diagrams were able to be copied onto the blog - so you will have to refer back to your copy on My Uni for the pics.

SECTION A                                                                              Each question is worth 1 mark

MULTIPLE CHOICE QUESTIONS – circle the correct answer

1.         What is the role of tropomyosin in skeletal muscles?

            A     tropomyosin is the name of a contracting unit.

            B     tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites      on the actin molecules.

            C     tropomyosin serves as a contraction inhibitor by blocking the actin binding sites          on the myosin molecules.

            D     tropomyosin is the receptor for the motor neuron neurotransmitter.

2.         Which muscle cells have the greatest ability to regenerate?

            A     skeletal

            B     cardiac

            C     smooth

            D     no muscle can regenerate

3.         What structure in skeletal muscle cells functions in calcium storage?

            A     sarcoplasmic reticulum

            B     mitochondria

            C     intermediate filament network

            D     myofibrillar network

4.         What does oxygen deficit represent?

            A     amount of energy needed for exertion

            B     the difference between the amount of oxygen needed for totally aerobic muscle          activity and the amount actually used

            C     the amount of oxygen taken into the body prior to the exertion

            D     the amount of oxygen taken into the body immediately after the exertion

5.         The major function of the sarcoplasmic reticulum in muscle contraction is to                      .

               

            A     make and store phosphocreatine

            B     synthesize actin and myosin myofilaments

            C     provide a source of myosin for the contraction process

            D     regulate intracellular calcium concentration

6.         What produces the striations of a skeletal muscle cell?

            A     a difference in the thickness of the sarcolemma

            B     the arrangement of myofilaments

            C     the sarcoplasmic reticulum

            D     the T tubules

7.         Which of the following are composed of myosin?

            A     thick filaments

            B     thin filaments

            C     all myofilaments

            D     Z discs

8.         During muscle contraction, myosin cross bridges attach to which active sites?

            A     myosin filaments

            B     actin filaments

            C     Z discs

            D     thick filaments

9.         Rigor mortis occurs because                               .

               

            A     the cells are dead

            B     sodium ions leak out of the muscle

            C     no ATP is available to release attached actin and myosin molecules

            D     proteins are beginning to break down, thus preventing a flow of calcium ions

10.       The term aponeurosis refers to                            .

               

            A     the bands of myofibrils

            B     a sheet-like indirect attachment to a skeletal element

            C     the rough endoplasmic reticulum

            D     the tropomyosin-troponin complex

11        The structure of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand tension stress?

               

            A     spongy bone

            B     irregular bone

            C     compact bone

            D     trabecular bone

12.       Yellow bone marrow contains a large percentage of ________.

               

            A     fat

            B     blood-forming cells

            C     elastic tissue

            D     Sharpey's fibers

13.       What kind of tissue is the forerunner of long bones in the embryo?

            A     elastic connective tissue

            B     dense fibrous connective tissue

            C     fibrocartilage

            D     hyaline cartilage

14.       Which structure allows the diaphysis of the bone to increase in length until early childhood, as well as shaping the articular surfaces?

            A     lacunae

            B     Haversian system

            C     epiphyseal plate

            D     epiphyseal line

15.       The periosteum is secured to the underlying bone by dense connective tissue called:

            A     Volkmann's canals

            B     a bony matrix with hyaline cartilage

            C     perforating (Sharpey's) fibers

            D     the struts of bone known as spicules

16.       Wolff's law is concerned with ________.

               

            A     vertical growth of bones being dependent on age

            B     the thickness and shape of a bone being dependent on stresses placed upon it

            C     the function of bone being dependent on shape

            D     the diameter of the bone being dependent on the ratio of osteoblasts to osteoclasts

               

17.       Spongy bone is made up of a framework called ________.

            A     osteons

            B     lamellar bone

            C     trabeculae

            D     osseous lamellae

18.        Which muscle can be made more prominent by turning the patient’s head to the side?

            A          Masseter

B          Trapezius

C          Platysma

D          Sternocleidomastoid

19.        Which of the following muscles in a prime mover in depression (opening) of the mandible?

            A          Stylohyoid

            B          Medial Pterygoid

            C          Trapezius

            D          Mylohyoid

20.        Which of the following ligaments is not associated with the TMJ?

            A          Temporomandibular Ligament

            B          Stylohyoid Ligament

            C          Stylomandibular Ligament

D          Sphenomandibular Ligament.

21.        Which of the following muscles in a prime mover in lateral movement of the mandible?

            A          Buccinator

            B          Medial Pterygoid

            C          Lateral Pterygoid

            D          Masseter.

22.        Which of the following muscles, when contacted, raises the lower lip, making scaling in the lower mandibular areas very difficult?

            A          Mentalis

            B          Orbicularis Oculi

            C          Geniohyoid

            D          Mylohyoid.

23.        Which anatomical feature of the TMJ secretes synovial fluid?

            A          Condyle

            B          Articular Disc

            C)         Synovial membrane lining the joint capsule

D)         Articular cartilage

                                                                                                              

24.        Which of the following muscle groups are the most highly toned?

            A          Facial Expression

            B          Hyoid groups

            C          Mastication

D          Cervial (neck)

25.        Which of the following muscles forms the floor of the oral cavity?

            A          Buccinator

            B          Orbicularis Oculi

            C          Depressor Labii Inferioris

            D          Mylohyoid.

True/False Questions - clearly circle either TRUE or FALSE to indicate your answer

26.       Hematopoiesis refers to the formation of blood cells within the red marrow cavities of certain bones.                                                                                    TRUE/FALSE

           

27.       Compact bone is replaced more often than spongy bone.              TRUE/FALSE

28.       Bones are classified by whether they are weight bearing or protective in function.

                                                                                                                        TRUE/FALSE

29.       The periosteum is a tissue that serves only to protect the bone because it is not supplied with nerves or blood vessels.                                                TRUE/FALSE

30.       Short, irregular, and flat bones have large marrow cavities in order to keep the weight of the bones light.                                                                  TRUE/FALSE

31.       The term osteoid refers to the organic part of the matrix of compact bones.

                                                                                                                        TRUE/FALSE

32.       In infants, the medullary cavity and all areas of spongy bone contain yellow bone marrow.                                                                                      TRUE/FALSE

33.       Sixty-five percent of the mass of bone is a compound called hydroxyapatite.

                                                                                                                        TRUE/FALSE

34.       All bones formed by intramembranous ossification are irregular bones.

                                                                                                                        TRUE/FALSE

35.       The trabeculae of spongy bone are oriented toward lines of stress.

                                                                                                            TRUE/FALSE

Try this application...

Doctors prescribe calcium channel blockers to control high blood pressure. They work by blocking the channels that allow calcium ions to diffuse into the sarcoplasm of muscle fibres, such as those found in cardiac muscle.

What role does calcium play in muscle contraction?

Extension question: (this is second year material but give it a go) How do you think blood pressure/hypertension is controlled with this medication? 

Muscle Tissue Revision Questions

The following questions will help you prepare for the online Quiz on the Muscle Tissue.

1. Describe the difference between muscle fibres, myofirils amd myofilaments.

2. What are the main differences between skeletal, smooth and cardiac muscle tissue.

3. What is meant by oxygen debt and the all or none principle?

4. (i) Name a muscle that is identified/named based on: a.  its origin and insertion .b. the orientation of the  fascicles c. movement d. shape and e. location.
    (ii) How do you distinguish between the insertion and the origin of a muscle?

5. Describe the following terms:

a.) motor neuron synaptic bulb
b) synaptic vesicles
c) synaptic cleft
d) motor end plate
e) t-tubules
f) sarcoplasmic reticulum
g) ACh and AChesterase

6.) What is the role of the Tropomyosin and the Troponin on the thin filament?

7.) What is a sarcomere?

8.) Distinguish between a tendon, aponeurosis and raphe. How is a tendon formed?


lets get some discussion going on these topics in preparation for the Trial test.

Thanks
Sophie